
Specific Examples
The use of SimuLase™ for the typical example of an edgeemitter and a VECSEL
are described in the examples guide.
Below
are some comparisons between experimental results and those of the fully microscopic calculations done
with SimuLase™ for an:
• InGaAsPbased edgeemitter operating at 1.3µm,
• InGaAsbased VECSEL operating at 1.04µm,
carrier losses and
resulting threshold currents in an:
• InGaSb/InAs/AlGaSb typeII 'W' structure operating at 3.4µm,
• InGaAsP/InPstructure operating at 1.3µm,
• InGaAs/InPstructure operating at 1.5µm,
• GaInNAs/GaAsstructure operating at 1.3µm
and
some more examples for
• Gain in an InGaN/GaN multi quantum well,
• Gain in an GaInNAs/GaAs multi quantum well,
• Gain and LWEF in an InGaAs/AlGaAs GRINSCH,
• Gain in an InGaAs/AlGaAs SCH,
• Absorption in an InGaAs/InP superlattice.
More examples can be found in the listed publications.
Edge Emitter and VECSEL
A detailed explanation on how to use SimuLase™
for the examples of an edge emitting ridge waveguide structure and a VECSEL structure,
including theoryexperiment comparisons for all important aspects,
ranging from the PL to the inputoutput characteristics,
can be found here.
The edge emitting example is based on Ref.
[30], the VECSEL example is based on Ref.
[41].
Screen grabs from SimuLase in the analysis of an edgeemitting structure (top) and a VECSEL (bottom).
InGaSb/InAs/AlGaSb 'W' structure for 3.4µm
Experimentally measured (solid lines)
and calculated (dashed lines) temperature dependent PL spectra for a midinfrared typeII 'W'
diode lase structure operating near 3.4µm at room temperature.
The active region consists of a short superlattice of five
InAs/GaInSb/InAs/AlGaSb wells.
Temperature dependent threshold current density for the midinfrared typeII 'W'
diode lase structure.
Dots: Experimental data. Solid line: Total theoretical loss current.
Dashed line: Calculated Auger loss current. Dotted line: Calculated radiative loss current.
For
more details on this example and calculations for radiative and Auger losses see
Ref.
[40].
Loss in an InGaAsP/InPstructure for 1.3µm
Experimentally measured (black signs)
and calculated (thick lines) temperature dependent loss currents at threshold for a structure
containing eight 4.4nm wide In_{0.83}Ga_{0.17}As_{0.67}P_{0.33}/InP quantum
wells lasing near 1.3µm. The experimental
data was extracted from A.F. Phillips, et al., IEEE J. Sel. Topics Quantum Electron., vol. 5, 401 (1999).
Black: total loss current; Red: radiative loss current due to spontaneous emission; Blue: Auger loss current.
For
more details on this example and calculations for radiative and Auger losses see
Ref.
[28].
Loss in an InGaAs/InPstructure for 1.5µm
Experimentally measured (black signs)
and calculated (thick lines) temperature dependent loss currents at threshold for a structure
containing four 2.5nm wide In_{0.65}Ga_{0.35}As/InP quantum
wells lasing near 1.5µm. The experimental
data was extracted from A.F. Phillips, et al., IEEE J. Sel. Topics Quantum Electron., vol. 5, 401 (1999).
Black: total loss current; Red: radiative loss current due to spontaneous emission; Blue: Auger loss current.
For
more details on this example and calculations for radiative and Auger losses see
Ref.
[28].
Loss in a GaInNAs/GaAsstructure for 1.3µm
Experimentally measured (thin lines and signs)
and calculated (thick lines) temperature dependent loss currents at threshold for a structure with a
6.4nm wide Ga_{0.66}In_{0.34}N_{0.018}As_{0.982}/GaAs quantum
well lasing near 1.3µm. The experimental
data was extracted from R. Fehse, et al., IEEE J. Sel. Topics Quantum Electron., vol. 8, 801 (2002).
Black: total loss current; Red: radiative loss current due to spontaneous emission; Blue: Auger loss current.
Losses due to defect recombination have been excluded from the shown experimental data.
The deviations between theory and experiment at high temperatures are probably due to internal heating
beyond the heat sink temperature.
For
more details on this example and calculations for radiative and Auger losses see
Ref.
[28].
Gain in InGaN/GaN
Experimentally measured (black signs)
and calculated (red lines) gain spectra for a structure
containing of 2nm wide In_{0.1}Ga_{0.9}N quantum
wells between 6nm wide GaN barriers. The experimental
data was extracted from B. Witzigmann, et al., Appl. Phys. Lett., 88, 021104 (2006).
For
more details on this example and calculations for wide bandgap nitride systems see
Ref.
[31] and Ref.[32].
Gain in GaInNAs/GaAs
Experimentally measured (blue
signs) and calculated (red lines) modal gain spectra for a structure
consisting of three 6nm wide In_{0.32}Ga_{0.68}N_{0.01}As_{0.99} quantum
wells between In_{0.05}Ga_{0.95}N_{0.015}As_{0.985} barriers. The experimental
data were obtained with the HakkiPaoli method.
The
sheet carrier densities in the calculations ranged from 3.75 to
8.25x10¹²/cm² with increments of 0.75x10¹²/cm², the injection
currents in the experiment were 7, 12, 14, 16 and 18mA.
For
more details see Ref.
[1].
Gain spectra for the same structure
as above but for a wider density range. It demonstrates the heating
of the device under high excitation conditions, leading to an
otherwise unusual red shift of the spectra. The comparison can
be used to determine internal temperatures and heating. The experimental
data was obtained with a different method than in the example
above, which allows to examine a wider density range, but is less
accurate. Blue: experimental results for 0, 5, 10, 15, 20, 30,
40, 50, 60 and 70mA. Red: theoretical results for the assumed
temperature of 300K and densities of 0, 1.5, 2.5, 3.0, 3.5 and
6.0x10¹²/cm². Green: theoretical results for 312K and 4.5 and
5.0x10¹²/cm². Magenta: 325K, 7.0*10¹²/cm².
Black: 337K and 9.0x10¹²/cm².
For
more details see
Ref.
[14].
Gain and LWEF in InGaAs/AlGaAsGRINSCH
Experimentally measured (blue
signs) and calculated (red lines) modal gain spectra for a structure
containing a 10nm wide In_{0.2}Ga_{0.8}As quantum
well between 85nm wide Al_{x}Ga_{1x}As graded index barriers
where the Aluminium concentration rises linearly from x=0.1 to x=0.6 with distance from the well.
Experimentally measured (blue signs) and calculated (red lines)
linewidth enhancement factors (alpha factors, LWEF) for the structure above and for
one with a smaller well width of only 5nm. The LWEF is taken at the spectral position of the
gain maximum.
For
more details see
Ref.
[2].
Gain in InGaAs/AlGaAsSCH
Theoryexperiment comparison
for a structure consisting of a 8nm wide In_{0.05}Ga_{0.95}As quantum
well between Al_{0.2}Ga_{0.8} barriers. Blue signs show the experimental
results, red lines the theoretical ones. The carrier densities
in the theory ranged from 0.6 to 3.0x10¹²/cm². The experimental
currents are from 0 to 20mA.
For
more details see Ref. [3].
Absorption in GaInAs/InPSuperlattice
Theoryexperiment comparison
for the excitonic absorption in a system of electronically coupled
InGaAs quantum wells that are separated by thin InP barriers ('superlattice')
under different external electric fields.
For the case of a field of 44 kV/cm the red dashed line shows
the theoretical result if the conduction band nonparabolicity
is neglected. The red solid lines have been calculated with this
nonparabolicity. The lines for different fields have been shifted
along the absorption axis for better clearity.
For more details see Ref.
[5].

