UV Laser Diode on sapphire substrate (example includes project files)
In SiLENSe package, simulation of the Laser Diode operation can be carried out with the account of both the carrier transport in the heterostructure and electromagnetic wave propagation, which, combined with the main functionality of the SiLENSe simulator.
The example presented is dedicated to explaining these features and demonstrating some results obtained using the SiLENSe Laser Edition.
Figure 2 Threshold current variation with the oscillation wavelength. Red line stands for simulation, blue dots represent experimental data
- computation of the band diagram, carrier transport, radiative and non-radiative recombination rates;
- computation of the carrier energy levels and wave functions;
- computation of the waveguide TE- and TM- modes, including advanced approximation of the refractive index dispersion in nitride materials and account for birefringence;
- computation of the optical gain and losses including computation of the gain spectrum and optical confinement factor for each quantum well and optical losses caused by the free carriers;
- calculation of total optical loss as a sum of mirror losses and losses caused by free carrier absorption;
- computation of threshold current density as a current at which modal gain becomes equal to the total optical loss;
- calculation of differential quantum efficiency.
Comparison of computations with the experimental data by M. Kneissl et.al., APL 82, 2386 (2003), is shown in Figure 2. Wavelength of 363-380 nm is controlled by variation of the In composition in QWs up to 4%.
More detailed discussion of the results can be found in preprint of our publication Effects of electron and optical confinement on performance of UV laser diodes, follow the link to read the article.