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:

• gain, absorption, and refractive index spectra,
• spontaneous emission (photo luminescence) spectra,
• loss currents due to radiative recombination,
• band structures, confinement potentials and wavefunctions.

In addition we can provide:

• loss currents due to Auger processes.

The later is provided only on special request since it is not needed for some systems (like wide bandgap nitride systems where Auger losses are negligible) and since it roughly doubles the numerical effort as compared to only the former four points.

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
• temperatures,
• 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 broadened data.

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.

SimuLase_Analyzer^TM, is shipped together with the GainDatabases. This GUI 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 this GUI and of a typical GainDatabase can be downloaded at our Download Demo-site.

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

• InGaAsP, AlGaAsP 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.