Appendix C GAIN Examples 1

C.1. Material system #1: AlGaAs/ AlGaAs 1

C.1.1. Calculation of material compositions and energy band edges. 1

C.1.2. Energy level calculations 3

C.1.3. Computation of Gain and Laser Characteristics 10

C.2 Material system #2: InGaAs/InGaAlAs/InP_ 16

C.2.1. Calculation of material compositions and energy band edges. 16

C.2.2. Energy level calculations 18

C.2.3 Computation of Gain and Laser Characteristics 23

C.3. Material system #3: InGaAs/InGaAsP/InP_ 31

C.3.1. Calculation of material compositions and energy band edges. 31

C.3.2. Energy level calculations 33

C.3.3. Computation of Gain and Laser Characteristics 40

C.4. Material system #4: InGaAlAs/InGaAlAs/InP_ 43

C.4.1. Calculation of material compositions and energy band edges. 43

C.4.2. Energy level calculations 49

C.4.3. Simulations of Gain and Laser properties 55

C.5. Material system #5: GaInP/AlzGawIn1-z-wP/Al0.5In0.5P_ 56

C.5.1. Calculation of material compositions and energy band edges. 56

C.5.2. Energy level calculations 63

C.5.3. Computation of Gain and Laser Characteristics 69

C.6. Material system #6: InGaAs/AlGaAs/AlGaAs 75

C.6.1. Calculation of material compositions and energy band edges. 75

C.6.2. Energy level calculations 89

C.6.3. Computation of Gain and Laser Characteristics 96

C.8. Material system #8: AlyInxGa1-x-yAs/AlzGa1-zAs/GaAs 89

C.8.1. Calculation of material compositions and energy band edges. 89

C.8.2. Energy level calculations 104

C.8.3. Computation of Gain and Laser Characteristics 111

C.9. Material system # 9: InGaAs/AlGaInAs/AlGaInAs  (substrate InP) 103

C.9.1. Calculation of material compositions and energy band edges. 103

C.9.2. Energy level calculations 119

C.9.3. Computation of Gain and Laser Characteristics 110

C.12. Material system #12: In(y)Ga(1-y)As(x)N(1-x)/GaAs (dilute N) 134

C.12.1. Calculation of material compositions and energy band edges. 134

C.12.2. Energy level calculations 136

C.12.3. Computation of Gain and Laser Characteristics 143

C.13. Material system #13: In(1-x)Ga(x)As(y)P(1-y)/GaAs 149

C.13.1. Calculation of material compositions and energy band edges. 149

C.13.2. Energy level calculations 152

C.13.3. Computation of Gain and Laser Characteristics 159


Appendix C GAIN Examples

 

In this appendix, the use of the GAIN program is demonstrated for ten material systems.  Each section below contains an example of how GAIN is used with one of these material systems.

 

C.1. Material system #1: AlGaAs/ AlGaAs

 

This is a simulation of a five-layer laser structure that contains a single quantum well (QW), two separated confinement heterostructure (SCH) layers, and two cladding layers as shown in Fig. C.1.1.

 

Figure C.1.1. Energy band diagram for the simple quantum well structure

 

C.1.1. Calculation of material compositions and energy band edges.

 

The first step of the GAIN program is to calculate the material compositions and energy band edges of the each layer. The user is asked to enter the photoluminescence wavelength, thickness, and strain of the QW, SCH, and cladding layers. After these parameters are input, the GAIN program generates two output files: cbandeg.dat and vbandeg.dat, containing the material compositions, and the conduction band edges and valence band edges respectively. The detailed explanation is provided in Chapter 2 of this manual.

 

a) The input parameters to the GAIN program in this step islisted in Table. C.4.1.

 

Table C.4.1. Input parameters to the GAIN program in this step.

Layer

l (um)

Strain

Thickness (Ǻ)

QW (AlxGa1-xAs)

0.87

------

50

SCH (AlxGa1-xAs)

0.74

------

60

Cladding (AlxGa1-xAs)

0.58

 

100

 

b) The steps in using the GAIN program to calculate the material compositions and energy band edges are listed in Table C.1.2

 

Table C.1.2. steps to run the GAIN program for necessary parameters.

ENTER 1 FOR THE NECESSARY PARAMETERS

       2 FOR THE ENERGY VALUES OF CONDUCTION BAND

       3 FOR THE ENERGY VALUES OF HEAVY HOLE BAND

       4 FOR THE ENERGY VALUES OF LIGHT HOLE BAND

       5 FOR THE LASER G-J AND G(LAMBDA)

       6 FOR RATE EQUATIONS(TWO SECTION MODEL INCLUDED)

       7 FOR EXIT

 

1

 

 ENTER 1 FOR AlGaAs/AlGaAs

       2 FOR InGaAsP/InGaAsP/InP

       3 FOR InGaAs/InGaAsP/InP

       4 FOR InGaAlAs/InGaAlAs/InP

       5 FOR GaInP/(AlGa)0.5In0.5P/AlInP

       6 FOR InGaAs/AlGaAs/AlGaAs

       7 FOR InGaAs/InGaAsP/Ga0.51In0.49P(MATCHED GaAs)

       8 FOR AlyInxGa1-x-yAs/AlzGa1-zAs/GaAs

       9 FOR InzGa1-zAs/AlyGaxIn1-x-yAs/InP

      10 FOR InGaAlAs/InGaAlAs/AlAsxSb1-x(matched InP)

      11 FOR InzGa1-zAs/AlyGaxIn1-x-yAs/AlAsxSb1-x

      12 FOR In(y)Ga(1-y)As(x)N(1-x)/GaAs (dilute N)

      13 FOR In(1-x)Ga(x)As(y)P(1-y)/GaAs

      14 FOR EXIT, BACK TO MAIN PAGE!

1

 INPUT THE LAYER # FOR GRIN STRUCTURE(STEP)

 STEP N=

2

  INPUT THE WELL WAVELENGTH (um)

0.87

  INPUT THE BARRIER WAVELENGTH (um)

0.74

  INPUT THE CLADDING WAVELENGTH (um)

0.58

  BANDGAP ENERGY OF QUANTUM WELL=   1.42528735632184       eV

  INPUT CLADDING, BARRIER,QUANTUM WELL WIDTH (A)

100 60 50

 

  WRITE CONDUCTION BAND PARAMETERS INTO CBANDEG.DAT

 

  WRITE VALENCE BAND PARAMETERS INTO VBANDEG.DAT

  INPUT 1 FOR NEW CALCULATION

        2 FOR EXIT

  INPUT =?

2

 

 ENTER 1 FOR AlGaAs/AlGaAs

       2 FOR InGaAsP/InGaAsP/InP

       3 FOR InGaAs/InGaAsP/InP

       4 FOR InGaAlAs/InGaAlAs/InP

       5 FOR GaInP/(AlGa)0.5In0.5P/AlInP

       6 FOR InGaAs/AlGaAs/AlGaAs

       7 FOR InGaAs/InGaAsP/Ga0.51In0.49P(MATCHED GaAs)

       8 FOR AlyInxGa1-x-yAs/AlzGa1-zAs/GaAs

       9 FOR InzGa1-zAs/AlyGaxIn1-x-yAs/InP

      10 FOR InGaAlAs/InGaAlAs/AlAsxSb1-x(matched InP)

      11 FOR InzGa1-zAs/AlyGaxIn1-x-yAs/AlAsxSb1-x

      12 FOR In(y)Ga(1-y)As(x)N(1-x)/GaAs (dilute N)

      13 FOR In(1-x)Ga(x)As(y)P(1-y)/GaAs

      14 FOR EXIT, BACK TO MAIN PAGE!

14

  THIS PROGRAM STOP HERE!, BACK TO MAIN PAGE

 

c) The output files, cbandeg.dat and vbandeg.dat are explained in Table C.1.3.

           

                Table C.1.3. Material compositions and band offsets:

 

a) cbandeg.dat for conduction band

************************************************************************

  QW strain    lattice constant

0.000000E+00  0.565311E-09

                                          material compositions

  layer thickness,                Al                                     conduction band edges

   0.10000000E+03   0.56115438E+00     0.0000000     0.4632184        cladding layer

   0.60000000E+02   0.20182492E+00     0.0000000     0.1627524        SCH layer

   0.50000000E+02   0.10323627E-02      0.0000000     0.0000000        quantum well

   0.60000000E+02   0.20182492E+00     0.0000000     0.1627524        SCH layer

   0.10000000E+03   0.56115438E+00     0.0000000     0.4632184        cladding layer

************************************************************************

 

b) vbandeg.dat for valence band

**************************************************** ********************

  QW strain    lattice constant

0.000000E+00  0.565311E-09

                                          material compositions

  layer thickness,                Al                                   valence band edges

   0.10000000E+03   0.56115438E+00     0.0000000    -0.2494253       cladding layer

   0.60000000E+02   0.20182492E+00     0.0000000    -0.0876359       SCH layer

   0.50000000E+02   0.10323627E-02      0.0000000     0.0000000       quantum well

   0.60000000E+02   0.20182492E+00     0.0000000    -0.0876359       SCH layer

   0.10000000E+03   0.56115438E+00     0.0000000    -0.2494253       cladding layer

************************************************************************

 

C.1.2. Energy level calculations

 

After the calculation of the material compositions and energy band edges, the GAIN program calculates energy levels in the conduction band and valence bands. The detailed explanations are discussed in Chapter 3 of this manual.

 

a) The steps of how to calculate the energy levels are shown in Table C.1.4.

 

Table C.4.4. Steps to calculate the energy levels

 

i) Steps to calculate the conduction band energy levels

ENTER 1 FOR THE NECESSARY PARAMETERS

       2 FOR THE ENERGY VALUES OF CONDUCTION BAND

       3 FOR THE ENERGY VALUES OF HEAVY HOLE BAND

       4 FOR THE ENERGY VALUES OF LIGHT HOLE BAND

       5 FOR THE LASER G-J AND G(LAMBDA)

       6 FOR RATE EQUATIONS(TWO SECTION MODEL INCLUDED)

       7 FOR EXIT

 

2

  INPUT THE NUMBER OF QUANTUM WELLS NUM=?

1

  INPUT TOTAL LAYERS FOR STRUCTURE--N ODD

  INPUT N=

5

  INPUT THE LOWEST POTENTIAL LAYER(1st Q-WELL) IC= ?

3

  INPUT THE SELECTED CENTER LAYER OF STRUCTURE ICR=

3

 *******************************************************

   INPUT I=1  FOR AlGaAs

         I=2  FOR InGaAsP

         I=3  FOR In1-xGaxAs/InGaAsP/InP

         I=4  FOR InGaAlAs/InGaAlAs

         I=5  FOR GaInP/(AlGa)0.5In0.5P/AlInP

         I=6  FOR InGaAs/AlGaAs/AlGaAs

         I=7  FOR InGaAs/InGaAsP/Ga0.51In0.49P(GaAs)

         I=8  FOR AlyInxGa1-x-yAs/AlzGa1-zAs/GaAs

         I=9  FOR InzGa1-zAs/AlxGayIn1-x-yAs/InP

         I=10 FOR InGaAlAs/InGaAlAs/AlAsxSb1-x(InP)

         I=11 FOR InzGa1-zAs/AlxGayIn1-x-yAs/AlAsxSb1-x

         I=12 FOR In(y)Ga(1-y)As(x)N(1-x)/GaAs

         I=13 FOR InGaAs/In(1-y)Ga(x)As(y)P(1-y)/GaAs

   INPUT I= ?

 *******************************************************

1

ENERGY EIGENVALUE===>  0.639537366786E-01 ERROR= .4682221E-14

ENERGY EIGENVALUE===>  0.192116584232E+00 ERROR= .4043667E-14

ENERGY EIGENVALUE===>  0.241763368724E+00 ERROR= .2926458E-14

ENERGY EIGENVALUE===>  0.310657613785E+00 ERROR= .2317973E-14

ENERGY EIGENVALUE===>  0.426765405664E+00 ERROR= .1485678E-14

 

  FOR CHECKING THE Schrodinger WAVE FUNCTION INPUT I==> 1

  SKIP INPUT I==> 2

  I=?

1

  INPUT THE EIGENVALUE

  EIGEN VALUE=

0.639537366786E-01

  INPUT THE NAME OF OUTPUT FILE

cb1.txt

 CONFINEMENT FACTOR OF    1 th LAYER = 0.82988859E-04

 CONFINEMENT FACTOR OF    2 th LAYER = 0.95857126E-01

 CONFINEMENT FACTOR OF    3 th LAYER = 0.80811977E+00

 CONFINEMENT FACTOR OF    4 th LAYER = 0.95857126E-01

 CONFINEMENT FACTOR OF    5 th LAYER = 0.82988859E-04

  INPUT NEW EIGENVALUE--> 1, BACK TO MAIN PAGE--> 2

  SELECT=?

1

  INPUT THE EIGENVALUE

  EIGEN VALUE=

0.192116584232E+00

  INPUT THE NAME OF OUTPUT FILE

cb2.txt

 CONFINEMENT FACTOR OF    1 th LAYER = 0.66304726E-02

 CONFINEMENT FACTOR OF    2 th LAYER = 0.39546197E+00

 CONFINEMENT FACTOR OF    3 th LAYER = 0.19581511E+00

 CONFINEMENT FACTOR OF    4 th LAYER = 0.39546197E+00

 CONFINEMENT FACTOR OF    5 th LAYER = 0.66304726E-02

  INPUT NEW EIGENVALUE--> 1, BACK TO MAIN PAGE--> 2

  SELECT=?

2

 

ii) Steps to calculate the heavy hole energy levels

 ENTER 1 FOR THE NECESSARY PARAMETERS

       2 FOR THE ENERGY VALUES OF CONDUCTION BAND

       3 FOR THE ENERGY VALUES OF HEAVY HOLE BAND

       4 FOR THE ENERGY VALUES OF LIGHT HOLE BAND

       5 FOR THE LASER G-J AND G(LAMBDA)

       6 FOR RATE EQUATIONS(TWO SECTION MODEL INCLUDED)

       7 FOR EXIT

3

  INPUT THE NUMBER OF QUANTUM WELLS NUM=?

1

  INPUT TOTAL LAYERS FOR STRUCTURE--N ODD

  INPUT N=

5

  INPUT THE HIGHEST POTENTIAL(1st Q-WELL) LAYER IC= ?

3

  INPUT THE SELECTED CENTER OF THE STRUCTURE ICR=?

3

 *******************************************************

   INPUT I=1  FOR AlGaAs

         I=2  FOR InGaAsP

         I=3  FOR In(1-x)Ga(x)As/InGaAsP/InP

         I=4  FOR InGaAlAs/InGaAlAs

         I=5  FOR GaInP/(AlGa)0.5In0.5P/AlInP

         I=6  FOR InGaAs/AlGaAs/AlGaAs

         I=7  FOR InGaAs/InGaAsP/Ga0.51In0.49P(GaAs)

         I=8  FOR AlyInxGa1-x-yAs/AlzGa1-zAs/GaAs

         I=9  FOR In(z)Ga(1-z)As/AlxGayIn1-x-yAs/InP

         I=10 FOR InGaAlAs/InGaAlAs/AlAsxSb1-x(InP)

         I=11 FOR InzGa1-zAs/AlxGayIn1-x-yAs/AlAsxSb1-x

         I=12 FOR In(y)Ga(1-y)As(x)N(1-x)/GaAs

         I=13 FOR InGaAs/In(1-x)Ga(x)As(y)P(1-y)/GaAs

   INPUT I= ?

 *******************************************************

1

 *******************************************************

 

  DOES THE STRUCTURE STRAIN OR STRAIN-COMPENSATED?

  IF STRAIN ONLY INPUT 1, STRAIN-COMPENSATED INPUT 2

  INPUT SELECT = ?

 

1

  ENERGY EIGENVALUE===> -0.238975151109E+00 ERROR= .3120685E-14

  ENERGY EIGENVALUE===> -0.197312089899E+00 ERROR= .4405413E-14

  ENERGY EIGENVALUE===> -0.166878855802E+00 ERROR= .2808856E-14

  ENERGY EIGENVALUE===> -0.139814196248E+00 ERROR= .4012646E-14

  ENERGY EIGENVALUE===> -0.111477421547E+00 ERROR= .3853459E-14

  ENERGY EIGENVALUE===> -0.102378800292E+00 ERROR= .1062527E-14

  ENERGY EIGENVALUE===> -0.681164844294E-01 ERROR= .2446502E-14

  ENERGY EIGENVALUE===> -0.188139816633E-01 ERROR= .1912450E-14

 

  FOR CHECKING THE Schrodinger WAVE FUNCTION INPUT I==> 1

  SKIP INPUT I==> 2

  I=?

1

  INPUT THE EIGENVALUE

  EIGEN VALUE=

-0.188139816633E-01

  INPUT THE NAME OF OUTPUT FILE

hh1.txt

 CONFINEMENT FACTOR OF    1 th LAYER = 0.38718131E-06

 CONFINEMENT FACTOR OF    2 th LAYER = 0.35292976E-01

 CONFINEMENT FACTOR OF    3 th LAYER = 0.92941327E+00

 CONFINEMENT FACTOR OF    4 th LAYER = 0.35292976E-01

 CONFINEMENT FACTOR OF    5 th LAYER = 0.38718131E-06

  INPUT NEW EIGENVALUE--> 1, BACK TO MAIN PAGE--> 2

  SELECT=?

1

  INPUT THE EIGENVALUE

  EIGEN VALUE=

-0.681164844294E-01

  INPUT THE NAME OF OUTPUT FILE

hh2.txt

 CONFINEMENT FACTOR OF    1 th LAYER = 0.68925350E-04

 CONFINEMENT FACTOR OF    2 th LAYER = 0.18086577E+00

 CONFINEMENT FACTOR OF    3 th LAYER = 0.63813061E+00

 CONFINEMENT FACTOR OF    4 th LAYER = 0.18086577E+00

 CONFINEMENT FACTOR OF    5 th LAYER = 0.68925350E-04

  INPUT NEW EIGENVALUE--> 1, BACK TO MAIN PAGE--> 2

  SELECT=?

2

 

iii) Steps to calculate the light hole energy levels

ENTER 1 FOR THE NECESSARY PARAMETERS

       2 FOR THE ENERGY VALUES OF CONDUCTION BAND

       3 FOR THE ENERGY VALUES OF HEAVY HOLE BAND

       4 FOR THE ENERGY VALUES OF LIGHT HOLE BAND

       5 FOR THE LASER G-J AND G(LAMBDA)

       6 FOR RATE EQUATIONS(TWO SECTION MODEL INCLUDED)

       7 FOR EXIT

 

4

  INPUT THE NUMBER OF QUANTUM WELLS NUM=?

1

  INPUT TOTAL LAYERS FOR STRUCTURE--N ODD

  INPUT N=

5

  INPUT THE HIGHEST POTENTIAL(1st Q-WELL) LAYER IC= ?

3

  INPUT THE SELECTED CENTER OF THE STRUCTURE ICR=?

3

 *******************************************************

   INPUT I=1  FOR AlGaAs

         I=2  FOR InGaAsP

         I=3  FOR In(1-x)Ga(x)As/InGaAsP/InP

         I=4  FOR InGaAlAs/InGaAlAs

         I=5  FOR GaInP/(AlGa)0.5In0.5P/AlInP

         I=6  FOR InGaAs/AlGaAs/AlGaAs

         I=7  FOR InGaAs/InGaAsP/Ga0.51In0.49P(GaAs)

         I=8  FOR AlyInxGa1-x-yAs/AlzGa1-zAs/GaAs

         I=9  FOR In(z)Ga(1-z)As/AlxGayIn1-x-yAs/InP

         I=10 FOR InGaAlAs/InGaAlAs/AlAsxSb1-x(InP)

         I=11 FOR InzGa1-zAs/AlxGayIn1-x-yAs/AlAsxSb1-x

         I=12 FOR In(y)Ga(1-y)As(x)N(1-x)/GaAs

         I=13 FOR InGaAs/In(1-x)Ga(x)As(y)P(1-y)/GaAs

   INPUT I= ?

 *******************************************************

1

 *******************************************************

 

  DOES THE STRUCTURE STRAIN OR STRAIN-COMPENSATED?

  IF STRAIN ONLY INPUT 1, STRAIN-COMPENSATED INPUT 2

  INPUT SELECT = ?

 

1

  ENERGY EIGENVALUE===> -0.205954300457E+00 ERROR= .3173697E-14

  ENERGY EIGENVALUE===> -0.149979763519E+00 ERROR= .2832057E-14

  ENERGY EIGENVALUE===> -0.114996860133E+00 ERROR= .2360129E-14

  ENERGY EIGENVALUE===> -0.415229761969E-01 ERROR= .2788797E-14

 

  FOR CHECKING THE Schrodinger WAVE FUNCTION INPUT I==> 1

  SKIP INPUT I==> 2

  I=?

1

  INPUT THE EIGENVALUE

  EIGEN VALUE=

-0.415229761969E-01

  INPUT THE NAME OF OUTPUT FILE

lh1.txt

 CONFINEMENT FACTOR OF    1 th LAYER = 0.38818584E-03

 CONFINEMENT FACTOR OF    2 th LAYER = 0.12463156E+00

 CONFINEMENT FACTOR OF    3 th LAYER = 0.74996051E+00

 CONFINEMENT FACTOR OF    4 th LAYER = 0.12463156E+00

 CONFINEMENT FACTOR OF    5 th LAYER = 0.38818584E-03

  INPUT NEW EIGENVALUE--> 1, BACK TO MAIN PAGE--> 2

  SELECT=?

1

  INPUT THE EIGENVALUE

  EIGEN VALUE=

-0.114996860133E+00

  INPUT THE NAME OF OUTPUT FILE

lh2.txt

 CONFINEMENT FACTOR OF    1 th LAYER = 0.13841264E-01

 CONFINEMENT FACTOR OF    2 th LAYER = 0.41302518E+00

 CONFINEMENT FACTOR OF    3 th LAYER = 0.14626712E+00

 CONFINEMENT FACTOR OF    4 th LAYER = 0.41302518E+00

 CONFINEMENT FACTOR OF    5 th LAYER = 0.13841264E-01

  INPUT NEW EIGENVALUE--> 1, BACK TO MAIN PAGE--> 2

  SELECT=?

2

 

b) The main output file from this part of GAIN program is energy.dat, containing all the energy levels as shown in Table C.1.5. After the energy eigen values are calculated, the GAIN program asks the user whether he would like to check the wave envelope function or not. We suggest that the user check the wave envelope functions of the first and second energy levels for conduction and valence bands. The plots of the envelope functions are shown in Fig. C.1.2, Fig. C.1.3, Fig C.1.4. 

 

Table C.1.5. output file energy.dat

  CONDUCTION BAND ENERGY===>  0.639537366786E-01 ERROR= .4682221E-14

                                                   

  CONDUCTION BAND ENERGY===>  0.192116584232E+00 ERROR= .4043667E-14

                                                   

  CONDUCTION BAND ENERGY===>  0.241763368724E+00 ERROR= .2926458E-14

                                                   

  CONDUCTION BAND ENERGY===>  0.310657613785E+00 ERROR= .2317973E-14

                                                    

  CONDUCTION BAND ENERGY===>  0.426765405664E+00 ERROR= .1485678E-14

                                                   

  HEAVY HOLE ENERGY===> -0.238975151109E+00 ERROR= .3120685E-14

                                                    

  HEAVY HOLE ENERGY===> -0.197312089899E+00 ERROR= .4405413E-14

                                                   

  HEAVY HOLE ENERGY===> -0.166878855802E+00 ERROR= .2808856E-14

                                                    

  HEAVY HOLE ENERGY===> -0.139814196248E+00 ERROR= .4012646E-14

                                                   

  HEAVY HOLE ENERGY===> -0.111477421547E+00 ERROR= .3853459E-14

                                                   

  HEAVY HOLE ENERGY===> -0.102378800292E+00 ERROR= .1062527E-14

                                                   

  HEAVY HOLE ENERGY===> -0.681164844294E-01 ERROR= .2446502E-14

                                                   

  HEAVY HOLE ENERGY===> -0.188139816633E-01 ERROR= .1912450E-14

                                                   

  LIGHT HOLE ENERGY===> -0.205954300457E+00 ERROR= .3173697E-14

                                                   

  LIGHT HOLE ENERGY===> -0.149979763519E+00 ERROR= .2832057E-14

                                                   

  LIGHT HOLE ENERGY===> -0.114996860133E+00 ERROR= .2360129E-14

                                                   

  LIGHT HOLE ENERGY===> -0.415229761969E-01 ERROR= .2788797E-14

                                                    

 

Fig. C.1.2. Wave envelop functions for energy levels in conduction band

Fig. C.1.3. Wave envelop functions for heavy hole energy levels

 

Fig. C.1.4. Wave envelop functions for light hole energy levels


 

C.1.3. Computation of Gain and Laser Characteristics

 

This is the last step of simulations using the GAIN program. With the previous calculated material composition, energy band edges, energy levels, and other parameters like material loss and Auger coefficient, the GAIN program can simulate the threshold current, threshold current density, slope efficiency, optical gain and mode gain as functions of wavelengths and photo energies, and L-I curve. The details are explained in Chapter 4 of the manual.

 

In this part of GAIN program, the input file needs to be constructed with the results of the previous steps and according to the laser design. In this example, single quantum well structure is used to simulate a three-QW laser. For the two-quantum-well laser with a ridge length of 750 µm and ridge width of 3 µm, the input file is shown in Table C.1.6. The detailed steps of simulations are listed in Table C.1.7. The main output files: L-I curve, optical gain as a function of the wavelength, and mode gain vs. current density are plotted in Fig. C.1.5, Fig. C.1.6, and Fig. C.1.7.

 

a) The input file:

 

Table C.1.6. Input file for gain and threshold current calculation

cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc

c     1. Input the compositions, width of well, effective index        c

c        and lasing wavelength.                                        c

c     Ex: xx,xz,qy,xy,lx,n,lam                                         c

c     for different materials the following are the forms of inputs.   c

c                                                                      c

c     w -- > well, b -- > barrier  cxz and cxy for cladding.           c

c                                                                      c

c     a.  AlxGa1-xAs : xx (Al w) xz (Al b) qy (0) xy (0)               c

c     b.  In1-xGaxAsyP1-y : xx (Ga w) xz (Ga b) qy (As w) xy (As b)    c

c     c.  In1-xGaxAs/InGaAsP : xx (Ga w) xz (Ga b) qy (0) xy (As b)    c

c     d.  AlxGayIn1-x-yAs/InP : xx (Ga w) xz (Ga b) qy (Al w) xy (Al b)c

c     e.                                                               c

c     f.  InxGa1-xAs/AlGaAs : xx (In w) xz (0) qy (0) xy (Al b)        c

c     g.                                                               c

c     h.  AlyInxGa1-x-yAs/AlGaAs : xx (Al w) xz (al b) qy (In w) xz (0)c

c     i.  In1-xGaxAs/AlGaInAs : xx (In w) xz (0) qy (Al b) xy (Ga b)   c

c     j.  In(y)Ga(1-y)As(x)N(1-x) :xx(As w),xz(As, b),qy(In w),xy(In b)c

c     k.  InGaAs/InGaAsP/GaAs: xx (In w), (0), xz(Ga w) xy (As b)

c     2. Input the energy gap,temperature, barrier band edges(both bands)

c     Ex: eg,temp,ec,ev                                                c

cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc

0.10323627E-02 0.20182492E+00  0  0  6.0  3.50  0.82

1.42528735632184 298 0.1627524 0.0876359

cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc

c     3. Input the ist level sub-band energy levels.                   c

c     Ex: ec1,eh1,el1                                                  c

c                                                                      c

c     4. Input the material loss, reflectivities, number of quantum    c

c        wells and beta(for spontaneous emission).                     c

c     Ex: alpha,r1,r2,mm,beta.                                         c

cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc

0.639537366786E-01  0.188139816633E-01  0.415229761969E-01  1  0.681164844294E-01  1

12.0d0  0.30   0.30   1  5.D-5

cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc

c     5. Input the cavity length, ridge width, internal efficiency     c

c        Auger, strain(except AlGaAs,put 0) and confinement factor.    c

c     Ex: cl,cw,etha,ca,es,confine                                     c

c                                                                      c

c     6. Input the cladding composition and band edges.                c

c     Ex: cxz,cxy,ecc,evv                                              c

cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc

750.D-4  3D-4  0.96  1.00d-29   0.01  0.009834488

0.56115438E+00 0.0  0.4632184  0.2494253

 

b) The steps for these calculations mentioned are listed in Table C.1.7

 

Table C.1.7. The steps for the gain and threshold current density calculations

ENTER 1 FOR THE NECESSARY PARAMETERS

       2 FOR THE ENERGY VALUES OF CONDUCTION BAND

       3 FOR THE ENERGY VALUES OF HEAVY HOLE BAND

       4 FOR THE ENERGY VALUES OF LIGHT HOLE BAND

       5 FOR THE LASER G-J AND G(LAMBDA)

       6 FOR RATE EQUATIONS(TWO SECTION MODEL INCLUDED)

       7 FOR EXIT

 

5

  THE INPUT FILE NAME=

in1_sys1_new.tex

  SELECT MATERIAL=?

  1--AlGaAs

  2--InGaAsP

  3--In1-zGazAs/InGaAsP/InP

  4-- InGaAlAs

  5--GaInP/AlzGawIn1-z-wP/Al0.5In0.5P

  6-- InxGa1-xAs/AlxGa1-xAs/AlGaAs

  7--In1-xGaxAs/InGaAsP/GaxIn1-xP(X=0.51) MATCHED TO GaAs

  8--AlyInxGa1-x-yAs/AlzGa1-zAs/GaAs

  9--InzGa1-zAs/AlxGayIn1-x-yAs/InP

  10-- InGaAlAs/InGaAlAs/AlAsSb

  11--InzGa1-zAs/AlxGayIn1-x-yAs/AlAsSb

  12--In(y)Ga(1-y)As(x)N(1-x)/GaAs

  13--InGaAs/In(1-x)Ga(x)As(y)P(1-y)/GaAs

  INPUT SELECTION

1

 INPUT MODE = ? FOR TE--> MODE =1, FOR TM--> MODE =2

  INPUT TE OR TM ?

1

 IF EL1 BELOW EH1 THEN SELECT 1, OTHERWISE SELECT 2

  SELECTION=?

1

  **************************************************

 CALCULATE THE EFFECTIVE MASS

  **************************************************

  FOR QUASI-FERMI LEVEL SELECT=1,

  FOR READ EXISTING QUASI-FERMI LEVEL SELECT=2

  SELECT=?

1

 

 J(LEAKAGE)=0.537974D+00 A/cm^2  N=0.239674D+19 1/cm^3

 J(LEAKAGE)=0.554846D+00 A/cm^2  N=0.241654D+19 1/cm^3

 J(LEAKAGE)=0.572232D+00 A/cm^2  N=0.243634D+19 1/cm^3

 J(LEAKAGE)=0.590147D+00 A/cm^2  N=0.245614D+19 1/cm^3

……….

J(LEAKAGE)=0.215349D+04 A/cm^2  N=0.788120D+19 1/cm^3

 J(LEAKAGE)=0.221784D+04 A/cm^2  N=0.790100D+19 1/cm^3

 J(LEAKAGE)=0.228410D+04 A/cm^2  N=0.792080D+19 1/cm^3

 J(LEAKAGE)=0.235231D+04 A/cm^2  N=0.794060D+19 1/cm^3

 J(LEAKAGE)=0.242253D+04 A/cm^2  N=0.796040D+19 1/cm^3

 J(LEAKAGE)=0.249481D+04 A/cm^2  N=0.798020D+19 1/cm^3

 J(LEAKAGE)=0.256922D+04 A/cm^2  N=0.800000D+19 1/cm^3

 **************************************************

 G(J) PARAMETERS FROM SINGLE WELL

 Go=0.218113D+02 1/cm  Jo=0.303353D+03 A/cm^2

 

 G(N) PARAMETERS FROM SINGLE WELL

 NGo=0.221783D+04 1/cm  XNo=0.136717D+19 1/cm^3

 

 Jtr=0.111597D+03 A/cm^2  NTR=0.502953D+18 1/cm^3

 

 

 THE OPTIMUM NUMBER OF QUANTUM WELL FOLLOWS THE ARTICLE

 BY McIlory et al. IEEE JQE-21 1985.

 

 THE OPTIMUM NUMBER OF QUANTUM WELL Nopt =           2

 INPUT Nopt(CAN BE DIFFERENT FROM ABOVE CALCULATION)=?

2

  NUMBER OF QUANTUM WELL(MAY OR MAY NOT BE Nopt)=?

2

 

  **************************************************

  **************************************************

  1ST CHECK USE SINGLE WELL TIMES # OF WELLS

  **************************************************

  **************************************************

  2ND CHECK FOLLOWS FORMULA BY McIlory IN IEEE

  JOURNAL OF QUANTUM ELECTRONIC QE-21 1985.

  **************************************************

  Gth=  28.0530 1/cm Nth=0.176316D+19 1/cm^3 IY=   85

  1ST CHECK Jth=   806.35405951 A/cm^2

  2ND CHECK Jth=   631.98567 A/cm^2

 

  1ST CHECK Ith=0.181430D+02 mA NUMBER OF WELLS=  2

  2ND CHECK Ith=0.142197D+02 mA

 

 **************************************************

CALCULATE THE P-I RELATION

 

NDATA=         316

 **************************************************

 CALCULATE THE SLOPE: mW/mA Y=A+BX

 CONSTANT A=  -7.3929014   SLOPE B=   0.4074803

 

 **************************************************

 INPUT POWER PO FOR THE LINEWIDTH, PO=0 FOR STOP

 INPUT PO=    mW

0

 INPUT 1 FOR THE DYNAMIC CALCULATION. 2 FOR SKIP

 INPUT =

2

  K-FACTOR= 0.35774 nS  MAXIUM FREQ.= 24.8387 GHz

 

  **************************************************

  INPUT 1 FOR CALCULATE THE GAIN(E) RELATION.

 

  INPUT 2 FOR CALCULATE THE LINEWIDTH ENHENCEMENT

  FACTOR AND PHOTON ENERGY RELATION

 

  INPUT 3 FOR EXIT THE PROGRAM

 

 THE INPUT # IS

1

 INPUT FERMILEVELS IN C-BAND, V-BAND, AND CARRIER DENSITY

0.139680787212E+00 -0.953800948086E-02 0.200075187970E+19

 CALCULATE THE CONVOLUTION GAIN(E) COEFFICIENT

  **************************************************

 INPUT THE NAME FOR THE CONVOLUTION OPTICAL GAIN(LAMBDA)

COGLa.txt

  **************************************************

 INPUT THE NAME FOR THE CONVOLUTION MODE GAIN(LAMBDA)

CMGLa.txt

 INPUT THE NAME FOR THE CONVOLUTION OPTICAL GAIN(E)

COGEa.txt

  **************************************************

 INPUT THE NAME FOR THE CONVOLUTION MODE GAIN(E)

CMGEa.txt

  **************************************************

 INPUT 1 FOR REPEAT THE G(E) CALCULATION

 INPUT 2 FOR REPEAT THE ALPHA(E) CALCULATION

 INPUT 3 FOR EXIT

1

  **************************************************

  INPUT 1 FOR CALCULATE THE GAIN(E) RELATION.

 

  INPUT 2 FOR CALCULATE THE LINEWIDTH ENHENCEMENT

  FACTOR AND PHOTON ENERGY RELATION

 

  INPUT 3 FOR EXIT THE PROGRAM

 

 THE INPUT # IS

1

 INPUT FERMILEVELS IN C-BAND, V-BAND, AND CARRIER DENSITY

0.160216100041E+00 -0.259237429430E-02 0.251553884712E+19

 CALCULATE THE CONVOLUTION GAIN(E) COEFFICIENT

  **************************************************

 INPUT THE NAME FOR THE CONVOLUTION OPTICAL GAIN(LAMBDA)

COGLb.txt

  **************************************************

 INPUT THE NAME FOR THE CONVOLUTION MODE GAIN(LAMBDA)

CMGLb.txt

 INPUT THE NAME FOR THE CONVOLUTION OPTICAL GAIN(E)

COGEb.txt

  **************************************************

 INPUT THE NAME FOR THE CONVOLUTION MODE GAIN(E)

CMGEb.txt

  **************************************************

 INPUT 1 FOR REPEAT THE G(E) CALCULATION

 INPUT 2 FOR REPEAT THE ALPHA(E) CALCULATION

 INPUT 3 FOR EXIT

3

ENTER 1 FOR THE NECESSARY PARAMETERS

       2 FOR THE ENERGY VALUES OF CONDUCTION BAND

       3 FOR THE ENERGY VALUES OF HEAVY HOLE BAND

       4 FOR THE ENERGY VALUES OF LIGHT HOLE BAND

       5 FOR THE LASER G-J AND G(LAMBDA)

       6 FOR RATE EQUATIONS(TWO SECTION MODEL INCLUDED)

       7 FOR EXIT

 

7

 

c) The Output characteristics of designed laser from step 5 are summarized in Table C.1.7.

 

Table C.1.7 Characteristics of the designed laser

Optimized number of QWs (Nopt)

2

Number of QWs

2

Slope efficiency (%)

40.75

Jth (A/cm^2)

806.35 - 1st check, for matching threshold conditions

631.99 – 2nd check, using McIlory method

Ith (mA)

18.14  - 1st check, for matching threshold conditions

14.22  - 2nd check, using McIlory method

Peak l at operating temperature (um)

0.819 um for carrier density of 2.0E18 /cm3

0.819 um for carrier density of 2.5E18 /cm3

Peak material gain (1/cm)

3619.36/cm for carrier density of 2.0E18 /cm3

4386.09 /cm for carrier density of 2.5E18 /cm3

 


 

Fig. C.1.5. L-I curve of the laser

Fig. C.1.6. Optical gain-l curve of the laser

 

                                    

      Fig. C.1.7. Mode gain as a function of current density (J)


 

C.2 Material system #2: InGaAs/InGaAlAs/InP

 

This is a simulation of a seventeen-layer laser structure that contains four quantum wells (QW), two separated confinement heterostructure (SCH) layers, and two cladding layers as shown in Fig. C.2.1. This device is a real one for research purpose. We will see the characteristics of this device.

 

Figure C.2.2. Energy band diagram for the simple quantum well structure

 

C.2.1. Calculation of material compositions and energy band edges.

 

The first step of the GAIN program is to calculate the material compositions and energy band edges of the each layer. The user is asked to enter the photoluminescence wavelength, thickness, and strain of the QW, SCH, and cladding layers. After these parameters are input, the GAIN program generates two output files: cbandeg.dat and vbandeg.dat, containing the material compositions, and the conduction band edges and valence band edges respectively. The detailed explanation is provided in Chapter 2 of this manual.

 

a) The input parameters to the GAIN program in this step are listed in Table. C.2.1.

 

Table C.2.1. Input parameters to the GAIN program in this step.

Layer

l (um)

Strain

Thickness (Ǻ)

QW (Ga1-xInxAsyP1-y)

1.525

-0.012

60

SCH (Ga1-xInxAsyP1-y)

1.28

 

50

Cladding (Ga1-xInxAsyP1-y)

0.98

 

100

 

b) The steps in using the GAIN program to calculate the material compositions and energy band edges are listed in Table C.2.2

 

Table C.2.2. steps to run the GAIN program for necessary parameters.

ENTER 1 FOR THE NECESSARY PARAMETERS

       2 FOR THE ENERGY VALUES OF CONDUCTION BAND

       3 FOR THE ENERGY VALUES OF HEAVY HOLE BAND

       4 FOR THE ENERGY VALUES OF LIGHT HOLE BAND

       5 FOR THE LASER G-J AND G(LAMBDA)

       6 FOR RATE EQUATIONS(TWO SECTION MODEL INCLUDED)

       7 FOR EXIT

1

 

 ENTER 1 FOR AlGaAs/AlGaAs

       2 FOR InGaAsP/InGaAsP/InP

       3 FOR InGaAs/InGaAsP/InP

       4 FOR InGaAlAs/InGaAlAs/InP

       5 FOR GaInP/(AlGa)0.5In0.5P/AlInP

       6 FOR InGaAs/AlGaAs/AlGaAs

       7 FOR InGaAs/InGaAsP/Ga0.51In0.49P(MATCHED GaAs)

       8 FOR AlyInxGa1-x-yAs/AlzGa1-zAs/GaAs

       9 FOR InzGa1-zAs/AlyGaxIn1-x-yAs/InP

      10 FOR InGaAlAs/InGaAlAs/AlAsxSb1-x(matched InP)

      11 FOR InzGa1-zAs/AlyGaxIn1-x-yAs/AlAsxSb1-x

      12 FOR In(y)Ga(1-y)As(x)N(1-x)/GaAs (dilute N)

      13 FOR In(1-x)Ga(x)As(y)P(1-y)/GaAs

      14 FOR EXIT, BACK TO MAIN PAGE!

2

 INPUT THE LAYER # FOR GRIN STRUCTURE(STEP)

 STEP N=

2

  INPUT THE WELL WAVELENGTH (um)

1.525

  INPUT THE BARRIER WAVELENGTH (um)

1.28

  INPUT THE CLADDING WAVELENGTH (um)

98

  BANDGAP ENERGY OF QUANTUM WELL=   0.683804000019804

  INPUT CLADDING, BARRIER,QUANTUM WELL WIDTH (A)

100 50 60

 

  In1-xGaxAsyP1-y, in output read Ga first then AsIN OUTPUT READ Ga FIRST THEN As

 

FOR InGaAsP, only compress strain (~1.5%) available

INPUT EX

-0.012

 

FOR LATTICE MATCHED BARRIER SELECT --> 1

FOR STRAIN COMPENSATED SELECT -- 2

 

INPUT SELECTION===> ?

1

 

WRITE CONDUCTION BAND PARAMETERS INTO CBANDEG.DAT

 

  WRITE VALENCE BAND PARAMETERS INTO VBANDEG.DAT

  INPUT 1 FOR NEW CALCULATION, 2 FOR EXIT

  I= ?

2

 

  ENTER 1 FOR AlGaAs/AlGaAs

       2 FOR InGaAsP/InGaAsP/InP

       3 FOR InGaAs/InGaAsP/InP

       4 FOR InGaAlAs/InGaAlAs/InP

       5 FOR GaInP/(AlGa)0.5In0.5P/AlInP

       6 FOR InGaAs/AlGaAs/AlGaAs

       7 FOR InGaAs/InGaAsP/Ga0.51In0.49P(MATCHED GaAs)

       8 FOR AlyInxGa1-x-yAs/AlzGa1-zAs/GaAs

       9 FOR InzGa1-zAs/AlyGaxIn1-x-yAs/InP

      10 FOR InGaAlAs/InGaAlAs/AlAsxSb1-x(matched InP)

      11 FOR InzGa1-zAs/AlyGaxIn1-x-yAs/AlAsxSb1-x

      12 FOR In(y)Ga(1-y)As(x)N(1-x)/GaAs (dilute N)

      13 FOR In(1-x)Ga(x)As(y)P(1-y)/GaAs

      14 FOR EXIT, BACK TO MAIN PAGE!

14

  THIS PROGRAM STOP HERE!, BACK TO MAIN PAGE

 

c) The output files, cbandeg.dat and vbandeg.dat are explained in Table C.2.3.

           

                Table C.2.3. Material compositions and band offsets:

 

a) cbandeg.dat for conduction band

************************************************************************

  QW strain    lattice constant

-.120000E-01  0.593923E-09

                                        material compositions

     layer thickness,                Ga                      Al        conduction band edges

    0.10000000E+03   0.50731155E-01     0.1116804     0.1763546        cladding layer

    0.50000000E+02   0.25335652E+00     0.5501187     0.0606978        SCH layer

0.60000000E+02   0.10405969E+00     0.5965452     0.0481108        quantum well

    0.50000000E+02   0.25335652E+00     0.5501187     0.0606978        SCH layer

0.10000000E+03   0.50731155E-01     0.1116804     0.1763546         cladding layer

************************************************************************

 

 

b) vbandeg.dat for valence band

**************************************************** ********************

  QW strain    lattice constant

-.120000E-01  0.593923E-09

                                          material compositions

  layer thickness,                Ga                      Al        valence band edges

    0.10000000E+03   0.50731155E-01     0.1116804    -0.2758368        cladding layer

    0.50000000E+02   0.25335652E+00     0.5501187    -0.0949375        SCH layer

    0.60000000E+02   0.10405969E+00     0.5965452    -0.0240554        quantum well

    0.50000000E+02   0.25335652E+00     0.5501187    -0.0949375        SCH layer

0.10000000E+03   0.50731155E-01     0.1116804    -0.2758368        cladding layer

************************************************************************

 

C.2.2. Energy level calculations

 

After the calculation of the material compositions and energy band edges, the GAIN program calculates energy levels in the conduction band and valence bands. The detailed explanations are discussed in Chapter 3 of this manual.

 

a) The steps of how to calculate the energy levels are shown in Table C.2.4.

 

Table C.2.4. Steps to calculate the energy levels

 

i) Steps to calculate the conduction band energy levels

ENTER 1 FOR THE NECESSARY PARAMETERS

       2 FOR THE ENERGY VALUES OF CONDUCTION BAND

       3 FOR THE ENERGY VALUES OF HEAVY HOLE BAND

       4 FOR THE ENERGY VALUES OF LIGHT HOLE BAND

       5 FOR THE LASER G-J AND G(LAMBDA)

       6 FOR RATE EQUATIONS(TWO SECTION MODEL INCLUDED)

       7 FOR EXIT

2

  INPUT THE NUMBER OF QUANTUM WELLS NUM=?

1

  INPUT TOTAL LAYERS FOR STRUCTURE--N ODD

  INPUT N=

5

  INPUT THE LOWEST POTENTIAL LAYER(1st Q-WELL) IC= ?

3

  INPUT THE SELECTED CENTER LAYER OF STRUCTURE ICR=

3

 *******************************************************

   INPUT I=1  FOR AlGaAs

         I=2  FOR InGaAsP

         I=3  FOR In1-xGaxAs/InGaAsP/InP

         I=4  FOR InGaAlAs/InGaAlAs

         I=5  FOR GaInP/(AlGa)0.5In0.5P/AlInP

         I=6  FOR InGaAs/AlGaAs/AlGaAs

         I=7  FOR InGaAs/InGaAsP/Ga0.51In0.49P(GaAs)

         I=8  FOR AlyInxGa1-x-yAs/AlzGa1-zAs/GaAs

         I=9  FOR InzGa1-zAs/AlxGayIn1-x-yAs/InP

         I=10 FOR InGaAlAs/InGaAlAs/AlAsxSb1-x(InP)

         I=11 FOR InzGa1-zAs/AlxGayIn1-x-yAs/AlAsxSb1-x

         I=12 FOR In(y)Ga(1-y)As(x)N(1-x)/GaAs

         I=13 FOR InGaAs/In(1-y)Ga(x)As(y)P(1-y)/GaAs

   INPUT I= ?

 *******************************************************

2

  ENERGY EIGENVALUE===>  0.670294366291E-01 ERROR= .3576162E-14

  ENERGY EIGENVALUE===>  0.101465108959E+00 ERROR= .3081508E-14

  ENERGY EIGENVALUE===>  0.155412249439E+00 ERROR= .2750090E-14

 

  FOR CHECKING THE Schrodinger WAVE FUNCTION INPUT I==> 1

  SKIP INPUT I==> 2

  I=?

1

  INPUT THE EIGENVALUE

  EIGEN VALUE=

0.670294366291E-01

  INPUT THE NAME OF OUTPUT FILE

cb1.txt

CONFINEMENT FACTOR OF    1 th LAYER = 0.11124994E-01

 CONFINEMENT FACTOR OF    2 th LAYER = 0.18768431E+00

 CONFINEMENT FACTOR OF    3 th LAYER = 0.60238139E+00

 CONFINEMENT FACTOR OF    4 th LAYER = 0.18768431E+00

 CONFINEMENT FACTOR OF    5 th LAYER = 0.11124994E-01

  INPUT NEW EIGENVALUE--> 1, BACK TO MAIN PAGE--> 2

  SELECT=?

1

  INPUT THE EIGENVALUE

  EIGEN VALUE=

0.101465108959

  INPUT THE NAME OF OUTPUT FILE

cb2.txt

CONFINEMENT FACTOR OF    1 th LAYER = 0.46526184E-01

 CONFINEMENT FACTOR OF    2 th LAYER = 0.36258718E+00

 CONFINEMENT FACTOR OF    3 th LAYER = 0.18177326E+00

 CONFINEMENT FACTOR OF    4 th LAYER = 0.36258718E+00

 CONFINEMENT FACTOR OF    5 th LAYER = 0.46526184E-01

  INPUT NEW EIGENVALUE--> 1, BACK TO MAIN PAGE--> 2

  SELECT=?

2

 

ii) Steps to calculate the heavy hole energy levels

 ENTER 1 FOR THE NECESSARY PARAMETERS

       2 FOR THE ENERGY VALUES OF CONDUCTION BAND

       3 FOR THE ENERGY VALUES OF HEAVY HOLE BAND

       4 FOR THE ENERGY VALUES OF LIGHT HOLE BAND

       5 FOR THE LASER G-J AND G(LAMBDA)

       6 FOR RATE EQUATIONS(TWO SECTION MODEL INCLUDED)

       7 FOR EXIT

3

  INPUT THE NUMBER OF QUANTUM WELLS NUM=?

1

  INPUT TOTAL LAYERS FOR STRUCTURE--N ODD

  INPUT N=

5

  INPUT THE HIGHEST POTENTIAL(1st Q-WELL) LAYER IC= ?

3

  INPUT THE SELECTED CENTER OF THE STRUCTURE ICR=?

3

 *******************************************************

   INPUT I=1  FOR AlGaAs

         I=2  FOR InGaAsP

         I=3  FOR In(1-x)Ga(x)As/InGaAsP/InP

         I=4  FOR InGaAlAs/InGaAlAs

         I=5  FOR GaInP/(AlGa)0.5In0.5P/AlInP

         I=6  FOR InGaAs/AlGaAs/AlGaAs

         I=7  FOR InGaAs/InGaAsP/Ga0.51In0.49P(GaAs)

         I=8  FOR AlyInxGa1-x-yAs/AlzGa1-zAs/GaAs

         I=9  FOR In(z)Ga(1-z)As/AlxGayIn1-x-yAs/InP

         I=10 FOR InGaAlAs/InGaAlAs/AlAsxSb1-x(InP)

         I=11 FOR InzGa1-zAs/AlxGayIn1-x-yAs/AlAsxSb1-x

         I=12 FOR In(y)Ga(1-y)As(x)N(1-x)/GaAs

         I=13 FOR InGaAs/In(1-x)Ga(x)As(y)P(1-y)/GaAs

   INPUT I= ?

 *******************************************************

2

 *******************************************************

 

  DOES THE STRUCTURE STRAIN OR STRAIN-COMPENSATED?

  IF STRAIN ONLY INPUT 1, STRAIN-COMPENSATED INPUT 2

  INPUT SELECT = ?

1

  ENERGY EIGENVALUE===> -0.266289655713E+00 ERROR= .2082626E-14

  ENERGY EIGENVALUE===> -0.220090610686E+00 ERROR= .2912430E-14

  ENERGY EIGENVALUE===> -0.186287733747E+00 ERROR= .4671376E-14

  ENERGY EIGENVALUE===> -0.140850401092E+00 ERROR= .8911599E-14

  ENERGY EIGENVALUE===> -0.122228608502E+00 ERROR= .4338441E-14

  ENERGY EIGENVALUE===> -0.101432618035E+00 ERROR= .1307382E-14

  ENERGY EIGENVALUE===> -0.428488013474E-01 ERROR= .2038714E-14

  ENERGY EIGENVALUE===>  0.509274076994E-02 ERROR= .2348418E-14

 

  FOR CHECKING THE Schrodinger WAVE FUNCTION INPUT I==> 1

  SKIP INPUT I==> 2

  I=?

1

  INPUT THE EIGENVALUE

  EIGEN VALUE=

0.509274076994E-02

  INPUT THE NAME OF OUTPUT FILE

hh1.txt

CONFINEMENT FACTOR OF    1 th LAYER = 0.43858757E-06

 CONFINEMENT FACTOR OF    2 th LAYER = 0.19049653E-01

 CONFINEMENT FACTOR OF    3 th LAYER = 0.96189982E+00

 CONFINEMENT FACTOR OF    4 th LAYER = 0.19049653E-01

 CONFINEMENT FACTOR OF    5 th LAYER = 0.43858757E-06

  SELECT=?

1

  INPUT THE EIGENVALUE

  EIGEN VALUE=

-0.428488013474E-01

  INPUT THE NAME OF OUTPUT FILE

hh2.txt

CONFINEMENT FACTOR OF    1 th LAYER = 0.18387626E-04

 CONFINEMENT FACTOR OF    2 th LAYER = 0.90457734E-01

 CONFINEMENT FACTOR OF    3 th LAYER = 0.81904776E+00

 CONFINEMENT FACTOR OF    4 th LAYER = 0.90457734E-01

 CONFINEMENT FACTOR OF    5 th LAYER = 0.18387626E-04

  INPUT NEW EIGENVALUE--> 1, BACK TO MAIN PAGE--> 2

  SELECT=?

2

 

iii) Steps to calculate the light hole energy levels

ENTER 1 FOR THE NECESSARY PARAMETERS

       2 FOR THE ENERGY VALUES OF CONDUCTION BAND

       3 FOR THE ENERGY VALUES OF HEAVY HOLE BAND

       4 FOR THE ENERGY VALUES OF LIGHT HOLE BAND

       5 FOR THE LASER G-J AND G(LAMBDA)

       6 FOR RATE EQUATIONS(TWO SECTION MODEL INCLUDED)

       7 FOR EXIT

4

  INPUT THE NUMBER OF QUANTUM WELLS NUM=?

1

  INPUT TOTAL LAYERS FOR STRUCTURE--N ODD

  INPUT N=

5

  INPUT THE HIGHEST POTENTIAL(1st Q-WELL) LAYER IC= ?

3

  INPUT THE SELECTED CENTER OF THE STRUCTURE ICR=?

3

 *******************************************************

   INPUT I=1  FOR AlGaAs

         I=2  FOR InGaAsP

         I=3  FOR In(1-x)Ga(x)As/InGaAsP/InP

         I=4  FOR InGaAlAs/InGaAlAs

         I=5  FOR GaInP/(AlGa)0.5In0.5P/AlInP

         I=6  FOR InGaAs/AlGaAs/AlGaAs

         I=7  FOR InGaAs/InGaAsP/Ga0.51In0.49P(GaAs)

         I=8  FOR AlyInxGa1-x-yAs/AlzGa1-zAs/GaAs

         I=9  FOR In(z)Ga(1-z)As/AlxGayIn1-x-yAs/InP

         I=10 FOR InGaAlAs/InGaAlAs/AlAsxSb1-x(InP)

         I=11 FOR InzGa1-zAs/AlxGayIn1-x-yAs/AlAsxSb1-x

         I=12 FOR In(y)Ga(1-y)As(x)N(1-x)/GaAs

         I=13 FOR InGaAs/In(1-x)Ga(x)As(y)P(1-y)/GaAs

   INPUT I= ?

 *******************************************************

2

 *******************************************************

 

  DOES THE STRUCTURE STRAIN OR STRAIN-COMPENSATED?

  IF STRAIN ONLY INPUT 1, STRAIN-COMPENSATED INPUT 2

  INPUT SELECT = ?

1

  ENERGY EIGENVALUE===> -0.235564886491E+00 ERROR= .4251760E-14

  ENERGY EIGENVALUE===> -0.159589791816E+00 ERROR= .2633269E-14

  ENERGY EIGENVALUE===> -0.968705335737E-01 ERROR= .1268730E-14

 

  FOR CHECKING THE Schrodinger WAVE FUNCTION INPUT I==> 1

  SKIP INPUT I==> 2

  I=?

1

  INPUT THE EIGENVALUE

  EIGEN VALUE=

-0.968705335737E-01

  INPUT THE NAME OF OUTPUT FILE

lh1.txt

CONFINEMENT FACTOR OF    1 th LAYER = 0.83034669E-02

 CONFINEMENT FACTOR OF    2 th LAYER = 0.20626333E+00

 CONFINEMENT FACTOR OF    3 th LAYER = 0.57086641E+00

 CONFINEMENT FACTOR OF    4 th LAYER = 0.20626333E+00

 CONFINEMENT FACTOR OF    5 th LAYER = 0.83034669E-02

  INPUT NEW EIGENVALUE--> 1, BACK TO MAIN PAGE--> 2

  SELECT=?

1

  INPUT THE EIGENVALUE

  EIGEN VALUE=

-0.159589791816E+00

  INPUT THE NAME OF OUTPUT FILE

lh2.txt

CONFINEMENT FACTOR OF    1 th LAYER = 0.44635531E-01

 CONFINEMENT FACTOR OF    2 th LAYER = 0.39731088E+00

 CONFINEMENT FACTOR OF    3 th LAYER = 0.11610718E+00

 CONFINEMENT FACTOR OF    4 th LAYER = 0.39731088E+00

 CONFINEMENT FACTOR OF    5 th LAYER = 0.44635531E-01

  INPUT NEW EIGENVALUE--> 1, BACK TO MAIN PAGE--> 2

  SELECT=?

2

 

b) The main output file from this part of GAIN program is energy.dat, containing all the energy levels as shown in Table C.2.5. After the energy eigen values are calculated, the GAIN program asks the user whether he would like to check the wave envelope function or not. We suggest that the user check the wave envelope functions of the first and second energy levels for conduction and valence bands. The plots of the envelope functions are shown in Fig. C.2.2, Fig. C.2.3, Fig C.2.4. 

 

Table C.2.5 Output file energy.dat

  CONDUCTION BAND ENERGY===>  0.670294366291E-01 ERROR= .3576162E-14

                                                   

  CONDUCTION BAND ENERGY===>  0.101465108959E+00 ERROR= .3081508E-14

                                                   

  CONDUCTION BAND ENERGY===>  0.155412249439E+00 ERROR= .2750090E-14

                                                   

  HEAVY HOLE ENERGY===> -0.266289655713E+00 ERROR= .2082626E-14

                                                    

  HEAVY HOLE ENERGY===> -0.220090610686E+00 ERROR= .2912430E-14

                                                   

  HEAVY HOLE ENERGY===> -0.186287733747E+00 ERROR= .4671376E-14

                                                    

  HEAVY HOLE ENERGY===> -0.140850401092E+00 ERROR= .8911599E-14

                                                   

  HEAVY HOLE ENERGY===> -0.122228608502E+00 ERROR= .4338441E-14

                                                   

  HEAVY HOLE ENERGY===> -0.101432618035E+00 ERROR= .1307382E-14

                                                   

  HEAVY HOLE ENERGY===> -0.428488013474E-01 ERROR= .2038714E-14

                                                   

  HEAVY HOLE ENERGY===>  0.509274076994E-02 ERROR= .2348418E-14

                                                   

  LIGHT HOLE ENERGY===> -0.235564886491E+00 ERROR= .4251760E-14

                                                   

  LIGHT HOLE ENERGY===> -0.159589791816E+00 ERROR= .2633269E-14

                                                   

  LIGHT HOLE ENERGY===> -0.968705335737E-01 ERROR= .1268730E-14

 

Fig. C.2.2. Wave envelop functions for energy levels in conduction band

Fig. C.2.3. Wave envelope functions for heavy hole energy levels. There is some rounding error with plot

 

Fig. C.2.4. Wave envelope functions for light hole energy levels


 

C.2.3 Computation of Gain and Laser Characteristics

 

This is the last step of simulations using the GAIN program. With the previous calculated material composition, energy band edges, energy levels, and other parameters like material loss and Auger coefficient, the GAIN program can simulate the threshold current, threshold current density, slope efficiency, optical gain and mode gain as functions of wavelengths and photon energies, and L-I curve. The details are explained in Chapter 4 of the manual.

 

In this part of GAIN program, the input file needs to be constructed with the results of the previous steps and according to the laser design. In this example, single quantum well structure is used to simulate a three-QW laser. For the three-quantum-well laser with a ridge length of 750 µm and ridge width of 3 µm, the input file is shown in Table C.2.6. The detailed steps of simulations are listed in Table C.2.7. The main output files: L-I curve, optical gain as a function of  the wavelength, and mode gain vs. current density are plotted in Fig. C.2.5, Fig. C.2.6, and Fig. C.2.7.

 

a) The input file:

 

Table C.2.6. Input file for gain and threshold current calculation

cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc

c     1. Input the compositions, width of well, effective index        c

c        and lasing wavelength.                                        c

c     Ex: xx,xz,qy,xy,lx,n,lam                                         c

c     for different materials the following are the forms of inputs.   c

c                                                                      c

c     w -- > well, b -- > barrier  cxz and cxy for cladding.           c

c                                                                      c

c     a.  AlxGa1-xAs : xx (Al w) xz (Al b) qy (0) xy (0)               c

c     b.  In1-xGaxAsyP1-y : xx (Ga w) xz (Ga b) qy (As w) xy (As b)    c

c     c.  In1-xGaxAs/InGaAsP : xx (Ga w) xz (Ga b) qy (0) xy (As b)    c

c     d.  AlxGayIn1-x-yAs/InP : xx (Ga w) xz (Ga b) qy (Al w) xy (Al b)c

c     e.                                                               c

c     f.  InxGa1-xAs/AlGaAs : xx (In w) xz (0) qy (0) xy (Al b)        c

c     g.                                                               c

c     h.  AlyInxGa1-x-yAs/AlGaAs : xx (Al w) xz (al b) qy (In w) xz (0)c

c     i.  In1-xGaxAs/AlGaInAs : xx (In w) xz (0) qy (Al b) xy (Ga b)   c

c     j.  In(y)Ga(1-y)As(x)N(1-x) :xx(As w),xz(As, b),qy(In w),xy(In b)c

c     k.  InGaAs/InGaAsP/GaAs: xx (In w), (0), xz(Ga w) xy (As b)

c     2. Input the energy gap,temperature, barrier band edges(both bands)

c     Ex: eg,temp,ec,ev                                                c

cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc

0.10405969 0.25335652 0.5965452 0.5501187 6.0 3.348741 1.31

0.94656 298 0.0606978  0.0949375

cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc

c     3. Input the ist level sub-band energy levels.                   c

c     Ex: ec1,eh1,el1                                                  c

c                                                                      c

c     4. Input the material loss, reflectivities, number of quantum    c

c        wells and beta(for spontaneous emission).                     c

c     Ex: alpha,r1,r2,mm,beta.                                         c

cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc

0.0670294366291 -0.509274076994E-02 0.096870533574 0.101465108959  0.0428488013474  0.159589791816

12.0d0  0.30   0.30   1  5.D-5

cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc

c     5. Input the cavity length, ridge width, internal efficiency     c

c        Auger, strain(except AlGaAs,put 0) and confinement factor.    c

c     Ex: cl,cw,etha,ca,es,confine                                     c

c                                                                      c

c     6. Input the cladding composition and band edges.                c

c     Ex: cxz,cxy,ecc,evv                                              c

cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc

750.D-4  3D-4  0.96  1.00d-29   0.000  0.009834488

0.050731155     0.1116804   0.1763546 0.2758368

 

b) The steps for these calculations mentioned are listed in Table C.2.7

 

Table C.2.7. The steps for the gain and threshold current density calculations

ENTER 1 FOR THE NECESSARY PARAMETERS

       2 FOR THE ENERGY VALUES OF CONDUCTION BAND

       3 FOR THE ENERGY VALUES OF HEAVY HOLE BAND

       4 FOR THE ENERGY VALUES OF LIGHT HOLE BAND

       5 FOR THE LASER G-J AND G(LAMBDA)

       6 FOR RATE EQUATIONS(TWO SECTION MODEL INCLUDED)

       7 FOR EXIT

 

5

  THE INPUT FILE NAME=

in1.tex

  SELECT MATERIAL=?

  1--AlGaAs

  2--InGaAsP

  3--In1-zGazAs/InGaAsP/InP

  4-- InGaAlAs

  5--GaInP/AlzGawIn1-z-wP/Al0.5In0.5P

  6-- InxGa1-xAs/AlxGa1-xAs/AlGaAs

  7--In1-xGaxAs/InGaAsP/GaxIn1-xP(X=0.51) MATCHED TO GaAs

  8--AlyInxGa1-x-yAs/AlzGa1-zAs/GaAs

  9--InzGa1-zAs/AlxGayIn1-x-yAs/InP

  10-- InGaAlAs/InGaAlAs/AlAsSb

  11--InzGa1-zAs/AlxGayIn1-x-yAs/AlAsSb

  12--In(y)Ga(1-y)As(x)N(1-x)/GaAs

  13--InGaAs/In(1-x)Ga(x)As(y)P(1-y)/GaAs

  INPUT SELECTION

2

 INPUT MODE = ? FOR TE--> MODE =1, FOR TM--> MODE =2

  INPUT TE OR TM ?

1

 IF EL1 BELOW EH1 THEN SELECT 1, OTHERWISE SELECT 2

  SELECTION=?

1

  **************************************************

 CALCULATE THE EFFECTIVE MASS

  **************************************************

  FOR QUASI-FERMI LEVEL SELECT=1,

  FOR READ EXISTING QUASI-FERMI LEVEL SELECT=2

  SELECT=?

1

 

 J(LEAKAGE)=0.522156D-01 A/cm^2  N=0.328772D+19 1/cm^3

 J(LEAKAGE)=0.544163D-01 A/cm^2  N=0.330752D+19 1/cm^3

 J(LEAKAGE)=0.567097D-01 A/cm^2  N=0.332732D+19 1/cm^3

 J(LEAKAGE)=0.590996D-01 A/cm^2  N=0.334712D+19 1/cm^3

……….

 

  J(LEAKAGE)=0.685423D+04 A/cm^2  N=0.788120D+19 1/cm^3

  J(LEAKAGE)=0.689811D+04 A/cm^2  N=0.790100D+19 1/cm^3

  J(LEAKAGE)=0.694207D+04 A/cm^2  N=0.792080D+19 1/cm^3

  J(LEAKAGE)=0.698612D+04 A/cm^2  N=0.794060D+19 1/cm^3

  J(LEAKAGE)=0.703024D+04 A/cm^2  N=0.796040D+19 1/cm^3

  J(LEAKAGE)=0.707444D+04 A/cm^2  N=0.798020D+19 1/cm^3

  J(LEAKAGE)=0.711872D+04 A/cm^2  N=0.800000D+19 1/cm^3

**************************************************

G(J) PARAMETERS FROM SINGLE WELL

  G(J) PARAMETERS FROM SINGLE WELL

  Go=0.704410D+01 1/cm  Jo=0.147036D+03 A/cm^2

 

  G(N) PARAMETERS FROM SINGLE WELL

  NGo=0.716265D+03 1/cm  XNo=0.126817D+19 1/cm^3

 

  Jtr=0.540917D+02 A/cm^2  NTR=0.466534D+18 1/cm^3

 

  THE OPTIMUM NUMBER OF QUANTUM WELL FOLLOWS THE ARTICLE

  BY McIlory et al. IEEE JQE-21 1985.

 

  THE OPTIMUM NUMBER OF QUANTUM WELL Nopt =           4

  INPUT Nopt(CAN BE DIFFERENT FROM ABOVE CALCULATION)=?

4

  NUMBER OF QUANTUM WELL(MAY OR MAY NOT BE Nopt)=?

4

 

    **************************************************

  **************************************************

  1ST CHECK USE SINGLE WELL TIMES # OF WELLS

  **************************************************

  **************************************************

  2ND CHECK FOLLOWS FORMULA BY McIlory IN IEEE

  JOURNAL OF QUANTUM ELECTRONIC QE-21 1985.

  **************************************************

  Gth=  28.0530 1/cm Nth=0.629724D+19 1/cm^3 IY=  314

   1ST CHECK Jth=  5406.36686808 A/cm^2

   2ND CHECK Jth=   612.65148 A/cm^2

 

   1ST CHECK Ith=0.121643D+03 mA NUMBER OF WELLS=  4

   2ND CHECK Ith=0.137847D+02 mA

 

  **************************************************

 CALCULATE THE P-I RELATION

 

 NDATA=          87

  **************************************************

  CALCULATE THE SLOPE: mW/mA Y=A+BX

  CONSTANT A= -32.6181898   SLOPE B=   0.2681463

 

  **************************************************

  INPUT POWER PO FOR THE LINEWIDTH, PO=0 FOR STOP

  INPUT PO=    mW

0

 INPUT 1 FOR THE DYNAMIC CALCULATION. 2 FOR SKIP

 INPUT =

2

  K-FACTOR= 0.58163 nS  MAXIUM FREQ.= 15.2773 GHz

 

  **************************************************

  INPUT 1 FOR CALCULATE THE GAIN(E) RELATION.

 

  INPUT 2 FOR CALCULATE THE LINEWIDTH ENHENCEMENT

  FACTOR AND PHOTONN ENERGY RELATION

 

  INPUT 3 FOR EXIT THE PROGRAM

 

 THE INPUT # IS

1

 INPUT FERMILEVELS IN C-BAND, V-BAND, AND CARRIER DENSITY

0.117426601301  -0.161989946432E-01 0.209974937343E+19

 CALCULATE THE CONVOLUTION GAIN(E) COEFFICIENT

  **************************************************

 INPUT THE NAME FOR THE CONVOLUTION OPTICAL GAIN(LAMBDA)

ol1.txt

  **************************************************

 INPUT THE NAME FOR THE CONVOLUTION MODE GAIN(LAMBDA)

ml1.txt

 INPUT THE NAME FOR THE CONVOLUTION OPTICAL GAIN(E)

oe1.txt

  **************************************************

 INPUT THE NAME FOR THE CONVOLUTION MODE GAIN(E)

me1.txt

  **************************************************

 INPUT 1 FOR REPEAT THE G(E) CALCULATION

 INPUT 2 FOR REPEAT THE ALPHA(E) CALCULATION

 INPUT 3 FOR EXIT

1

  **************************************************

  INPUT 1 FOR CALCULATE THE GAIN(E) RELATION.

 

  INPUT 2 FOR CALCULATE THE LINEWIDTH ENHENCEMENT

  FACTOR AND PHOTONN ENERGY RELATION

 

  INPUT 3 FOR EXIT THE PROGRAM

 

 THE INPUT # IS

1

 INPUT FERMILEVELS IN C-BAND, V-BAND, AND CARRIER DENSITY

0.138679340946 -0.441266076305E-02 0.301052631579E+19

 CALCULATE THE CONVOLUTION GAIN(E) COEFFICIENT

  **************************************************

 INPUT THE NAME FOR THE CONVOLUTION OPTICAL GAIN(LAMBDA)

ol2.txt

  **************************************************

 INPUT THE NAME FOR THE CONVOLUTION MODE GAIN(LAMBDA)

ml2.txt

 INPUT THE NAME FOR THE CONVOLUTION OPTICAL GAIN(E)

oe2.txt

  **************************************************

 INPUT THE NAME FOR THE CONVOLUTION MODE GAIN(E)

me2.txt

  **************************************************

 INPUT 1 FOR REPEAT THE G(E) CALCULATION

 INPUT 2 FOR REPEAT THE ALPHA(E) CALCULATION

 INPUT 3 FOR EXIT

3

ENTER 1 FOR THE NECESSARY PARAMETERS

       2 FOR THE ENERGY VALUES OF CONDUCTION BAND

       3 FOR THE ENERGY VALUES OF HEAVY HOLE BAND

       4 FOR THE ENERGY VALUES OF LIGHT HOLE BAND

       5 FOR THE LASER G-J AND G(LAMBDA)

       6 FOR RATE EQUATIONS(TWO SECTION MODEL INCLUDED)

       7 FOR EXIT

7

 

c) The Output characteristics of designed laser from step 5 are summarized in Table C.2.7.

 

Table C.2.7 Characteristics of the designed laser

Optimized number of QWs (Nopt)

4

Number of QWs

4

Slope efficiency (%)

26.8

Jth (A/cm^2)

5406.4 - 1st check, for matching threshold conditions

612.7 – 2nd check, using McIlory method

Ith (mA)

121  mA - 1st check, for matching threshold conditions

13.7 mA - 2nd check, using McIlory method

Peak l at operating temperature (um)

1.21 um for carrier density of 2.0E19 /cm3

1.18 um for carrier density of 3.0E19 /cm3

Peak material gain (1/cm)

2362 /cm for carrier density of 2.0E19 /cm3

3360 /cm for carrier density of 3.0E19 /cm3

 


 

Fig. C.2.5. L-I curve of the laser

 

Fig. C.2.6. Optical gain-l curve of the laser

 

Fig. C.2.7. Mode gain as a function of current density (J)


C.3. Material system #3: InGaAs/InGaAsP/InP

 

This is a simulation of a five-layer laser structure that contains a single quantum well (QW), two separated confinement heterostructure (SCH) layers, and two cladding layers as shown in Fig. C.3.1.

 

Figure C.3.3. Energy band diagram for the simple quantum well structure

 

C.3.1. Calculation of material compositions and energy band edges.

 

The first step of the GAIN program is to calculate the material compositions and energy band edges of the each layer. The user is asked to enter the photoluminescence wavelength, thickness, and strain of the QW, SCH, and cladding layers. After these parameters are input, the GAIN program generates two output files: cbandeg.dat and vbandeg.dat, containing the material compositions, and the conduction band edges and valence band edges respectively. The detailed explanation is provided in Chapter 2 of this manual.

 

a) The input parameters to the GAIN program in this step is listed in Table. C.3.1.

 

Table C.3.1. Input parameters to the GAIN program in this step.

Layer

l (um)

Strain

Thickness (Ǻ)

QW (InGaAs)

1.56

0.003507

100

SCH (In1-xGaxAsyP1-y)

1.21

0

100

Cladding (InP)

0.9185

 

1000

 

b) The steps in using the GAIN program to calculate the material compositions and energy band edges are listed in Table C.3.2

 

Table C.3.2. steps to run the GAIN program for necessary parameters.

ENTER 1 FOR THE NECESSARY PARAMETERS

       2 FOR THE ENERGY VALUES OF CONDUCTION BAND

       3 FOR THE ENERGY VALUES OF HEAVY HOLE BAND

       4 FOR THE ENERGY VALUES OF LIGHT HOLE BAND

       5 FOR THE LASER G-J AND G(LAMBDA)

       6 FOR RATE EQUATIONS(TWO SECTION MODEL INCLUDED)

       7 FOR EXIT

 

1

 

 ENTER 1 FOR AlGaAs/AlGaAs

       2 FOR InGaAsP/InGaAsP/InP

       3 FOR InGaAs/InGaAsP/InP

       4 FOR InGaAlAs/InGaAlAs/InP

       5 FOR GaInP/(AlGa)0.5In0.5P/AlInP

       6 FOR InGaAs/AlGaAs/AlGaAs

       7 FOR InGaAs/InGaAsP/Ga0.51In0.49P(MATCHED GaAs)

       8 FOR AlyInxGa1-x-yAs/AlzGa1-zAs/GaAs

       9 FOR InzGa1-zAs/AlyGaxIn1-x-yAs/InP

      10 FOR InGaAlAs/InGaAlAs/AlAsxSb1-x(matched InP)

      11 FOR InzGa1-zAs/AlyGaxIn1-x-yAs/AlAsxSb1-x

      12 FOR In(y)Ga(1-y)As(x)N(1-x)/GaAs (dilute N)

      13 FOR In(1-x)Ga(x)As(y)P(1-y)/GaAs

      14 FOR EXIT, BACK TO MAIN PAGE!

3

 INPUT THE LAYER # FOR GRIN STRUCTURE(STEP)

 STEP N=

2

  INPUT THE WELL WAVELENGTH (um)

1.56

  INPUT THE BARRIER WAVELENGTH (um)

1.21

  INPUT THE CLADDING WAVELENGTH (um)

0.9185

  BANDGAP ENERGY OF QUANTUM WELL=   0.79487179

  INPUT CLADDING, BARRIER,QUANTUM WELL WIDTH (A)

1000 100 100

 

  FOR BARRIER IS LATTICE MATCHED SELECT ==>1

  FOR BARRIER IS STRAIN COMPENSATED SELECT ==> 2

 

  SELECTION IS ===> ?

1

 

STRAIN FOR In1-xGaxAs= 3.507367375368143E-003

 

  WRITE CONDUCION BAND PARAMETERS INTO CBANDEG.DAT

 

  WRITE VALENCE BAND PARAMETERS INTO VBANDEG.DAT

  INPUT 1 FOR NEW CALCULATION,   2 FOR EXIT

  I =?

2

 

 ENTER 1 FOR AlGaAs/AlGaAs

       2 FOR InGaAsP/InGaAsP/InP

       3 FOR InGaAs/InGaAsP/InP

       4 FOR InGaAlAs/InGaAlAs/InP

       5 FOR GaInP/(AlGa)0.5In0.5P/AlInP

       6 FOR InGaAs/AlGaAs/AlGaAs

       7 FOR InGaAs/InGaAsP/Ga0.51In0.49P(MATCHED GaAs)

       8 FOR AlyInxGa1-x-yAs/AlzGa1-zAs/GaAs

       9 FOR InzGa1-zAs/AlyGaxIn1-x-yAs/InP

      10 FOR InGaAlAs/InGaAlAs/AlAsxSb1-x(matched InP)

      11 FOR InzGa1-zAs/AlyGaxIn1-x-yAs/AlAsxSb1-x

      12 FOR In(y)Ga(1-y)As(x)N(1-x)/GaAs (dilute N)

      13 FOR In(1-x)Ga(x)As(y)P(1-y)/GaAs

      14 FOR EXIT, BACK TO MAIN PAGE!

14

  THIS PROGRAM STOP HERE!, BACK TO MAIN PAGE

 

c) The output files, cbandeg.dat and vbandeg.dat are explained in Table C.3.3.

           

                Table C.3.3. Material compositions and band offsets:

 

a) cbandeg.dat for conduction band

************************************************************************

  QW strain    lattice constant

0.350737E-02 0.584822E-09

                                          material compositions

  layer thickness,                Ga                      As       conduction band edges

  0.10000000E+04   0.00000000E+00     0.0000000     0.1998462        cladding layer

   0.10000000E+03   0.21142234E+00     0.4603684     0.0827718        SCH layer

   0.10000000E+03   0.51884522E+00     0.0000000    -0.0190298        quantum well

   0.10000000E+03   0.21142234E+00     0.4603684     0.0827718        SCH layer

   0.10000000E+04   0.00000000E+00     0.0000000     0.1998462        cladding layer

************************************************************************

 

b) vbandeg.dat for valence band

**************************************************** ********************

  QW strain    lattice constant

 0.350737E-02  0.584822E-09

                                          material compositions

  layer thickness,                Ga                      As        valence band edges

   0.10000000E+04   0.00000000E+00     0.0000000    -0.3552821       cladding layer

   0.10000000E+03   0.21142234E+00     0.4603684    -0.1471498       SCH layer

   0.10000000E+03   0.51884522E+00     0.0000000     0.0095149       quantum well

   0.10000000E+03   0.21142234E+00     0.4603684    -0.1471498       SCH layer

   0.10000000E+04   0.00000000E+00     0.0000000    -0.3552821       cladding layer

************************************************************************

 

C.3.2. Energy level calculations

 

After the calculation of the material compositions and energy band edges, the GAIN program calculates energy levels in the conduction band and valence bands. The detailed explanations are discussed in Chapter 3 of this manual.

 

a) The steps of how to calculate the energy levels are shown in Table C.3.4.

 

Table C.3.4. Steps to calculate the energy levels

 

i) Steps to calculate the conduction band energy levels

ENTER 1 FOR THE NECESSARY PARAMETERS

       2 FOR THE ENERGY VALUES OF CONDUCTION BAND

       3 FOR THE ENERGY VALUES OF HEAVY HOLE BAND

       4 FOR THE ENERGY VALUES OF LIGHT HOLE BAND

       5 FOR THE LASER G-J AND G(LAMBDA)

       6 FOR RATE EQUATIONS(TWO SECTION MODEL INCLUDED)

       7 FOR EXIT

 

2

  INPUT THE NUMBER OF QUANTUM WELLS NUM=?

1

  INPUT TOTAL LAYERS FOR STRUCTURE--N ODD

  INPUT N=

5

  INPUT THE LOWEST POTENTIAL LAYER(1st Q-WELL) IC= ?

3

  INPUT THE SELECTED CENTER LAYER OF STRUCTURE ICR=

3

 *******************************************************

   INPUT I=1  FOR AlGaAs

         I=2  FOR InGaAsP

         I=3  FOR In1-xGaxAs/InGaAsP/InP

         I=4  FOR InGaAlAs/InGaAlAs

         I=5  FOR GaInP/(AlGa)0.5In0.5P/AlInP

         I=6  FOR InGaAs/AlGaAs/AlGaAs

         I=7  FOR InGaAs/InGaAsP/Ga0.51In0.49P(GaAs)

         I=8  FOR AlyInxGa1-x-yAs/AlzGa1-zAs/GaAs

         I=9  FOR InzGa1-zAs/AlxGayIn1-x-yAs/InP

         I=10 FOR InGaAlAs/InGaAlAs/AlAsxSb1-x(InP)

         I=11 FOR InzGa1-zAs/AlxGayIn1-x-yAs/AlAsxSb1-x

         I=12 FOR In(y)Ga(1-y)As(x)N(1-x)/GaAs

         I=13 FOR InGaAs/In(1-y)Ga(x)As(y)P(1-y)/GaAs

   INPUT I= ?

 *******************************************************

3

  ENERGY EIGENVALUE===>  0.102677331562E-01 ERROR= .4838213E-14

  ENERGY EIGENVALUE===>  0.829312203346E-01 ERROR= .3134953E-14

  ENERGY EIGENVALUE===>  0.116110587122E+00 ERROR= .1700480E-14

  ENERGY EIGENVALUE===>  0.137409592564E+00 ERROR= .2887171E-14

  ENERGY EIGENVALUE===>  0.193078448219E+00 ERROR= .2186428E-14

 

  FOR CHECKING THE Schrodinger WAVE FUNCTION INPUT I==> 1

  SKIP INPUT I==> 2

  I=?

1

  INPUT THE EIGENVALUE

  EIGEN VALUE=

0.0102677331562

 

  INPUT THE NAME OF OUTPUT FILE

cb1.txt

 CONFINEMENT FACTOR OF    1 th LAYER = 0.23125143E-04

 CONFINEMENT FACTOR OF    2 th LAYER = 0.60295889E-01

 CONFINEMENT FACTOR OF    3 th LAYER = 0.87936197E+00

 CONFINEMENT FACTOR OF    4 th LAYER = 0.60295889E-01

 CONFINEMENT FACTOR OF    5 th LAYER = 0.23125143E-04

  INPUT NEW EIGENVALUE--> 1, BACK TO MAIN PAGE--> 2

  SELECT=?

1

  INPUT THE EIGENVALUE

  EIGEN VALUE=

0.0829312203346

  INPUT THE NAME OF OUTPUT FILE

cb2.txt

 CONFINEMENT FACTOR OF    1 th LAYER = 0.30920015E-02

 CONFINEMENT FACTOR OF    2 th LAYER = 0.29765260E+00

 CONFINEMENT FACTOR OF    3 th LAYER = 0.39851080E+00

 CONFINEMENT FACTOR OF    4 th LAYER = 0.29765260E+00

 CONFINEMENT FACTOR OF    5 th LAYER = 0.30920015E-02

  INPUT NEW EIGENVALUE--> 1, BACK TO MAIN PAGE--> 2

  SELECT=?

2

 

ii) Steps to calculate the heavy hole energy levels

 ENTER 1 FOR THE NECESSARY PARAMETERS

       2 FOR THE ENERGY VALUES OF CONDUCTION BAND

       3 FOR THE ENERGY VALUES OF HEAVY HOLE BAND

       4 FOR THE ENERGY VALUES OF LIGHT HOLE BAND

       5 FOR THE LASER G-J AND G(LAMBDA)

       6 FOR RATE EQUATIONS(TWO SECTION MODEL INCLUDED)

       7 FOR EXIT

3

  INPUT THE NUMBER OF QUANTUM WELLS NUM=?

1

  INPUT TOTAL LAYERS FOR STRUCTURE--N ODD

  INPUT N=

5

  INPUT THE HIGHEST POTENTIAL(1st Q-WELL) LAYER IC= ?

3

  INPUT THE SELECTED CENTER OF THE STRUCTURE ICR=?

3

 *******************************************************

   INPUT I=1  FOR AlGaAs

         I=2  FOR InGaAsP

         I=3  FOR In(1-x)Ga(x)As/InGaAsP/InP

         I=4  FOR InGaAlAs/InGaAlAs

         I=5  FOR GaInP/(AlGa)0.5In0.5P/AlInP

         I=6  FOR InGaAs/AlGaAs/AlGaAs

         I=7  FOR InGaAs/InGaAsP/Ga0.51In0.49P(GaAs)

         I=8  FOR AlyInxGa1-x-yAs/AlzGa1-zAs/GaAs

         I=9  FOR In(z)Ga(1-z)As/AlxGayIn1-x-yAs/InP

         I=10 FOR InGaAlAs/InGaAlAs/AlAsxSb1-x(InP)

         I=11 FOR InzGa1-zAs/AlxGayIn1-x-yAs/AlAsxSb1-x

         I=12 FOR In(y)Ga(1-y)As(x)N(1-x)/GaAs

         I=13 FOR InGaAs/In(1-x)Ga(x)As(y)P(1-y)/GaAs

   INPUT I= ?

 *******************************************************

3

 *******************************************************

 

  DOES THE STRUCTURE STRAIN OR STRAIN-COMPENSATED?

  IF STRAIN ONLY INPUT 1, STRAIN-COMPENSATED INPUT 2

  INPUT SELECT = ?

 

1

 

  ENERGY EIGENVALUE===> -0.345448893969E+00 ERROR= .5479616E-14

  ENERGY EIGENVALUE===> -0.313421614966E+00 ERROR= .4977968E-14

  ENERGY EIGENVALUE===> -0.286023116439E+00 ERROR= .3741431E-14

  ENERGY EIGENVALUE===> -0.265617316582E+00 ERROR= .4216452E-14

  ENERGY EIGENVALUE===> -0.234960966106E+00 ERROR= .1892574E-14

  ENERGY EIGENVALUE===> -0.220233112417E+00 ERROR= .3492980E-14

  ENERGY EIGENVALUE===> -0.198687987806E+00 ERROR= .2194434E-14

  ENERGY EIGENVALUE===> -0.182167124769E+00 ERROR= .5669799E-14

  ENERGY EIGENVALUE===> -0.173478187551E+00 ERROR= .3761173E-14

  ENERGY EIGENVALUE===> -0.156637644140E+00 ERROR= .4590558E-14

  ENERGY EIGENVALUE===> -0.154444131718E+00 ERROR= .2538691E-14

  ENERGY EIGENVALUE===> -0.127480216412E+00 ERROR= .2519639E-14

  ENERGY EIGENVALUE===> -0.758643937665E-01 ERROR= .2498963E-14

  ENERGY EIGENVALUE===> -0.356919987894E-01 ERROR= .2709770E-14

  ENERGY EIGENVALUE===> -0.109370594171E-01 ERROR= .2119172E-14

 

  FOR CHECKING THE Schrodinger WAVE FUNCTION INPUT I==> 1

  SKIP INPUT I==> 2

  I=?

1

  INPUT THE EIGENVALUE

  EIGEN VALUE=

-0.0109370594171

  INPUT THE NAME OF OUTPUT FILE

hh1.txt

 CONFINEMENT FACTOR OF    1 th LAYER = 0.18195603E-12

 CONFINEMENT FACTOR OF    2 th LAYER = 0.48861990E-02

 CONFINEMENT FACTOR OF    3 th LAYER = 0.99022760E+00

 CONFINEMENT FACTOR OF    4 th LAYER = 0.48861990E-02

 CONFINEMENT FACTOR OF    5 th LAYER = 0.18195603E-12

  INPUT NEW EIGENVALUE--> 1, BACK TO MAIN PAGE--> 2

  SELECT=?

1

  INPUT THE EIGENVALUE

  EIGEN VALUE=

-0.0356919987894

  INPUT THE NAME OF OUTPUT FILE

hh2.txt

 CONFINEMENT FACTOR OF    1 th LAYER = 0.60477885E-11

 CONFINEMENT FACTOR OF    2 th LAYER = 0.20535375E-01

 CONFINEMENT FACTOR OF    3 th LAYER = 0.95892925E+00

 CONFINEMENT FACTOR OF    4 th LAYER = 0.20535375E-01

 CONFINEMENT FACTOR OF    5 th LAYER = 0.60477885E-11

  INPUT NEW EIGENVALUE--> 1, BACK TO MAIN PAGE--> 2

  SELECT=?

2

 

iii) Steps to calculate the light hole energy levels

ENTER 1 FOR THE NECESSARY PARAMETERS

       2 FOR THE ENERGY VALUES OF CONDUCTION BAND

       3 FOR THE ENERGY VALUES OF HEAVY HOLE BAND

       4 FOR THE ENERGY VALUES OF LIGHT HOLE BAND

       5 FOR THE LASER G-J AND G(LAMBDA)

       6 FOR RATE EQUATIONS(TWO SECTION MODEL INCLUDED)

       7 FOR EXIT

 

4

  INPUT THE NUMBER OF QUANTUM WELLS NUM=?

1

  INPUT TOTAL LAYERS FOR STRUCTURE--N ODD

  INPUT N=

5

  INPUT THE HIGHEST POTENTIAL(1st Q-WELL) LAYER IC= ?

3

  INPUT THE SELECTED CENTER OF THE STRUCTURE ICR=?

3

 *******************************************************

   INPUT I=1  FOR AlGaAs

         I=2  FOR InGaAsP

         I=3  FOR In(1-x)Ga(x)As/InGaAsP/InP

         I=4  FOR InGaAlAs/InGaAlAs

         I=5  FOR GaInP/(AlGa)0.5In0.5P/AlInP

         I=6  FOR InGaAs/AlGaAs/AlGaAs

         I=7  FOR InGaAs/InGaAsP/Ga0.51In0.49P(GaAs)

         I=8  FOR AlyInxGa1-x-yAs/AlzGa1-zAs/GaAs

         I=9  FOR In(z)Ga(1-z)As/AlxGayIn1-x-yAs/InP

         I=10 FOR InGaAlAs/InGaAlAs/AlAsxSb1-x(InP)

         I=11 FOR InzGa1-zAs/AlxGayIn1-x-yAs/AlAsxSb1-x

         I=12 FOR In(y)Ga(1-y)As(x)N(1-x)/GaAs

         I=13 FOR InGaAs/In(1-x)Ga(x)As(y)P(1-y)/GaAs

   INPUT I= ?

 *******************************************************

3

 *******************************************************

 

  DOES THE STRUCTURE STRAIN OR STRAIN-COMPENSATED?

  IF STRAIN ONLY INPUT 1, STRAIN-COMPENSATED INPUT 2

  INPUT SELECT = ?

 

1

  ENERGY EIGENVALUE===> -0.324350665429E+00 ERROR= .2529748E-14

  ENERGY EIGENVALUE===> -0.268485842580E+00 ERROR= .4118834E-14

  ENERGY EIGENVALUE===> -0.200300476894E+00 ERROR= .3413517E-14

  ENERGY EIGENVALUE===> -0.181133391050E+00 ERROR= .2018955E-14

  ENERGY EIGENVALUE===> -0.116983827560E+00 ERROR= .3183911E-14

  ENERGY EIGENVALUE===> -0.161551734944E-01 ERROR= .3222829E-14

 

  FOR CHECKING THE Schrodinger WAVE FUNCTION INPUT I==> 1

  SKIP INPUT I==> 2

  I=?

1

  INPUT THE EIGENVALUE

  EIGEN VALUE=

-0.0161551734944

  INPUT THE NAME OF OUTPUT FILE

lh1.txt

 CONFINEMENT FACTOR OF    1 th LAYER = 0.28197495E-05

 CONFINEMENT FACTOR OF    2 th LAYER = 0.39958233E-01

 CONFINEMENT FACTOR OF    3 th LAYER = 0.92007789E+00

 CONFINEMENT FACTOR OF    4 th LAYER = 0.39958233E-01

 CONFINEMENT FACTOR OF    5 th LAYER = 0.28197495E-05

  INPUT NEW EIGENVALUE--> 1, BACK TO MAIN PAGE--> 2

  SELECT=?

1

  INPUT THE EIGENVALUE

  EIGEN VALUE=

-0.116983827560

  INPUT THE NAME OF OUTPUT FILE

lh2.txt

 CONFINEMENT FACTOR OF    1 th LAYER = 0.39043702E-03

 CONFINEMENT FACTOR OF    2 th LAYER = 0.19969312E+00

 CONFINEMENT FACTOR OF    3 th LAYER = 0.59983288E-01

 CONFINEMENT FACTOR OF    4 th LAYER = 0.19969312E+00

 CONFINEMENT FACTOR OF    5 th LAYER = 0.39043702E-03

  INPUT NEW EIGENVALUE--> 1, BACK TO MAIN PAGE--> 2

  SELECT=?

2

 

b) The main output file from this part of GAIN program is energy.dat, containing all the energy levels as shown in Table C.3.5. After the energy eigen values are calculated, the GAIN program asks the user whether he would like to check the wave envelope function or not. We suggest that the user check the wave envelope functions of the first and second energy levels for conduction and valence bands. The plots of the envelope functions are shown in Fig. C.3.2, Fig. C.3.3, Fig C.3.4. 

 

Table C.3.5. output file energy.dat

  CONDUCTION BAND ENERGY===>  0.132273196491E+00 ERROR= .1825400E-14

                                                   

  CONDUCTION BAND ENERGY===>  0.338026920933E+00 ERROR= .2075989E-14

                                                   

  CONDUCTION BAND ENERGY===>  0.438393858497E+00 ERROR= .1374688E-14

                                                   

  CONDUCTION BAND ENERGY===>  0.500546559386E+00 ERROR= .1783885E-14

                                                   

  HEAVY HOLE ENERGY===> -0.190388140560E+00 ERROR= .3376657E-14

                                                   

  HEAVY HOLE ENERGY===> -0.178205351549E+00 ERROR= .2794590E-14

                                                   

  HEAVY HOLE ENERGY===> -0.146868929570E+00 ERROR= .1933278E-14

                                                   

  HEAVY HOLE ENERGY===> -0.649012884792E-01 ERROR= .1722105E-14

                                                   

  HEAVY HOLE ENERGY===> -0.584031671619E-02 ERROR= .1782035E-14

                                                   

  LIGHT HOLE ENERGY===> -0.224692198534E+00 ERROR= .5190988E-14

                                                   

  LIGHT HOLE ENERGY===> -0.169366776608E+00 ERROR= .3378719E-14

                                                    

  LIGHT HOLE ENERGY===> -0.978425419323E-01 ERROR= .2045359E-14

 

Fig. C.3.2. Wave envelop functions for energy levels in conduction band

Fig. C.3.3. Wave envelop functions for heavy hole energy levels

 

Fig. C.3.4. Wave envelop functions for light hole energy levels


 

C.3.3. Computation of Gain and Laser Characteristics

 

This is the last step of simulations using the GAIN program. With the previous calculated material composition, energy band edges, energy levels, and other parameters like material loss and Auger coefficient, the GAIN program can simulate the threshold current, threshold current density, slope efficiency, optical gain and mode gain as functions of wavelengths and photo energies, and L-I curve. The details are explained in Chapter 4 of the manual.

 

In this part of GAIN program, the input file needs to be constructed with the results of the previous steps and according to the laser design. In this example, a tensile single-quantum-well laser with a ridge length of 750µm and ridge width of 3 µm, the input file is shown in Table C.3.6. The detailed steps of simulations are listed in Table C.3.7. The main output files: L-I curve, optical gain as a function of  the wavelength, and mode gain vs. current density are plotted in Fig. C.3.5, Fig. C.3.6, and Fig. C.3.7.

 

a) The input file:

 

Table C.3.6. Input file for gain and threshold current calculation

ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc

c     1. Input the compositions, width of well, effective index         c

c        and lasing wavelength.                                         c

c     Ex: xx,xz,qy,xy,lx,n,lam                                          c

c     for different materials the following are the forms of inputs.    c

c                                                                       c

c     w -- > well, b -- > barrier  cxz and cxy for cladding.           c

c                                                                      c

c     a.  AlxGa1-xAs : xx (Al w) xz (Al b) qy (0) xy (0)               c

c     b.  In1-xGaxAsyP1-y : xx (Ga w) xz (Ga b) qy (As w) xy (As b)    c

c     c.  In1-xGaxAs/InGaAsP : xx (Ga w) xz (Ga b) qy (0) xy (As b)    c

c     d.  AlxGayIn1-x-yAs/InP : xx (Ga w) xz (Ga b) qy (Al w) xy (Al b)c

c     e.                                                               c

c     f.  InxGa1-xAs/AlGaAs : xx (In w) xz (0) qy (0) xy (Al b)        c

c     g.                                                               c

c     h.  AlyInxGa1-x-yAs/AlGaAs : xx (Al w) xz (al b) qy (In w) xz (0)c

c     i.  In1-xGaxAs/AlGaInAs : xx (In w) xz (0) qy (Al b) xy (Ga b)   c

c                                                                      c

c                                                                      c

c     2. Input the energy gap,temperature, barrier band edges(both bands)c

c     Ex: eg,temp,ec,ev                                                c

cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc

0.51884522 0.21142234 0.0 0.4603684 10.0 3.32 1.55

0.79487179 298 0.10718016 0.1566647

cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc

c     3. Input the ist level sub-band energy levels.                   c

c     Ex: ec1,eh1,el1                                                  c

c                                                                      c

c     4. Input the material loss, reflectivities, number of quantum    c

c        wells and beta(for spontaneous emission).                     c

c     Ex: alpha,r1,r2,mm,beta.                                         c

cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc

0.0102677331562 0.0109370594171 0.0161551734944 0.0829312203346 0.0356919987894 0.116983827560

10.0d0 0.3000 0.300 1 5.D-5

cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc

c     5. Input the cavity length, ridge width, internal efficiency     c

c        Auger, strain(except AlGaAs,put 0) and confinement factor.    c

c     Ex: cl,cw,etha,ca,es,confine                                     c

c                                                                      c

c     6. Input the cladding composition and band edges.                c

c     Ex: cxz,cxy,ecc,evv                                              c

cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc

500.D-4 3D-4 0.97 3.10d-29 0.0 0.018

0.00 0.00  0.218876 0.364797

 

b) The steps for these calculations mentioned are listed in Table C.3.7

 

Table C.3.7. The steps for the gain and threshold current density calculations

ENTER 1 FOR THE NECESSARY PARAMETERS

       2 FOR THE ENERGY VALUES OF CONDUCTION BAND

       3 FOR THE ENERGY VALUES OF HEAVY HOLE BAND

       4 FOR THE ENERGY VALUES OF LIGHT HOLE BAND

       5 FOR THE LASER G-J AND G(LAMBDA)

       6 FOR RATE EQUATIONS(TWO SECTION MODEL INCLUDED)

       7 FOR EXIT

 

5

  THE INPUT FILE NAME=

in1.tex

  SELECT MATERIAL=?

  1--AlGaAs

  2--InGaAsP

  3--In1-zGazAs/InGaAsP/InP

  4-- InGaAlAs

  5--GaInP/AlzGawIn1-z-wP/Al0.5In0.5P

  6-- InxGa1-xAs/AlxGa1-xAs/AlGaAs

  7--In1-xGaxAs/InGaAsP/GaxIn1-xP(X=0.51) MATCHED TO GaAs

  8--AlyInxGa1-x-yAs/AlzGa1-zAs/GaAs

  9--InzGa1-zAs/AlxGayIn1-x-yAs/InP

  10-- InGaAlAs/InGaAlAs/AlAsSb

  11--InzGa1-zAs/AlxGayIn1-x-yAs/AlAsSb

  12--In(y)Ga(1-y)As(x)N(1-x)/GaAs

  13--InGaAs/In(1-x)Ga(x)As(y)P(1-y)/GaAs

  INPUT SELECTION

3

 INPUT MODE = ? FOR TE--> MODE =1, FOR TM--> MODE =2

  INPUT TE OR TM ?

1

 IF EL1 BELOW EH1 THEN SELECT 1, OTHERWISE SELECT 2

  SELECTION=?

1

  **************************************************

 CALCULATE THE EFFECTIVE MASS

  **************************************************

  FOR QUASI-FERMI LEVEL SELECT=1,

  FOR READ EXISTING QUASI-FERMI LEVEL SELECT=2

  SELECT=?

1

 

 J(LEAKAGE)=0.104958D+03 A/cm^2  N=0.328772D+19 1/cm^3

 J(LEAKAGE)=0.108158D+03 A/cm^2  N=0.330752D+19 1/cm^3

 J(LEAKAGE)=0.111439D+03 A/cm^2  N=0.332732D+19 1/cm^3

 J(LEAKAGE)=0.114800D+03 A/cm^2  N=0.334712D+19 1/cm^3

……….

J(LEAKAGE)=0.245553D+05A/cm^2  N=0.788120D+19 1/cm^3

J(LEAKAGE)=0.246733D+05A/cm^2  N=0.790100D+19 1/cm^3

J(LEAKAGE)=0.247912D+05A/cm^2  N=0.792080D+19 1/cm^3

J(LEAKAGE)=0.249092D+05A/cm^2  N=0.794060D+19 1/cm^3

J(LEAKAGE)=0.250272D+05A/cm^2  N=0.796040D+19 1/cm^3

J(LEAKAGE)=0.251453D+05 A/cm^2  N=0.798020D+19 1/cm^3

J(LEAKAGE)=0.252633D+05 A/cm^2  N=0.800000D+19 1/cm^3

**************************************************

G(J) PARAMETERS FROM SINGLE WELL

  Go=0.178866D+02 1/cm    Jo=0.967184D+02 A/cm^2

 

  G(N) PARAMETERS FROM SINGLE WELL

  NGo=0.993699D+03 1/cm  XNo=0.951378D+18 1/cm^3

 

  Jtr=0.355807D+02 A/cm^2  NTR=0.349993D+18 1/cm^3

 

 

  THE OPTIMUM NUMBER OF QUANTUM WELL FOLLOWS THE ARTICLE

  BY McIlory et al. IEEE JQE-21 1985.

 

  THE OPTIMUM NUMBER OF QUANTUM WELL Nopt =