A Gain Database (Gain Table) is a collection of microscopically
calculated material properties for a structure or set of structures
as specified by the customer. A Gain Database generally contains:
• band structures, confinement potentials and wavefunctions,
• gain, absorption, and refractive index spectra,
• spontaneous emission (photo luminescence) spectra,
• loss currents due to radiative recombination,
• loss currents due to Auger processes,
• intraband (free carrier) absorption.
A typical "set of structures" includes a variation of one or more structural parameters
like the well width, the well composition (depth), strain, internal or external electric fields
etc. around a target structure.
For each structure the above mentioned properties are usually calculated for a set of
• carrier densities ranging from absorption to gain and
• TE- and TM-polarisation.
The spectra are calculated including the homogeneous broadening due to electron-electron and
electron-phonon scattering. The Gain Tables are shipped together with a program that allows
to apply arbitrary inhomogeneous broadenings to the the spectra.
If the customer provides typical experimental spontaneous emission spectra we derive from
them the typical inhomogeneous broadening using the method described in the
PL-Analysis section and include the correspondingly
The Gain Table is usually shipped as ASCII data that can be read by all customary
graphics programs. Also included is a report summarizing the main results.
A special version of SimuLase™ that includes
SimuLase_Designer™, is shipped together with the GainDatabases.
This software allows to investigate the structural layout, confinement energies, levels, wavefunctions and
optical modes, etc. It also allows
to easily browse through the results, apply inhomogeneous broadenings and shifts,
calculate derived quantities, like loss curents, gain for a given current or the linewidth
enhancement factor. It also allows to perform automated comparisons
to experimental data as described in the PL-Analysis section.
A free demo-version of these GUIs and of a typical GainDatabase can be downloaded at our
Gain Tables can be readily provided for various structural designs like
• single or multiple quantum wells,
• electronically coupled quantum wells,
• SCH or GRINSCH confinement layers,
• structures including internal electric fields due to dopants or piezoelectric effects,
• structures including external electric fields
and most standard materials like
• AlInGaAsSb for mid- to long-IR wavelengths,
• AlInGaAsP for telecom wavelengths,
• InGaAlP for visual wavelengths,
• dillute Nitrides (GaInNAs),
• wide bandgap Nitrides.
For more unconventional systems calculations can be provided based on a experimental-theoretical
collaboration in a consulting enviroment.
Besides deliverable Gain Tables we also provide our modeling capabilities
in a consulting enviroment. In such a case we can also provide (fully microscopic) tools to analyze effects
like free carrier absorption, carrier relaxation processes or non-equilibrium optical effects.