Theoretical comparison of mid–wavelength infrared and long–wavelength infrared lasers

The ideal performance of bulk, quantum-well and superlattice interband and inter-subband active regions for III-V laser diodes emitting from 3-11 μm was compared. For traditional (non-cascade) devices the comparison was based on the maximum net gain per unit volumetric current. Based on this figure of merit, optimal thicknesses for such active regions were evaluated assuming a separate confinement region design. The ideal performance of cascaded and non-cascaded intersubband and interband laser active regions were directly compared by considering the net material gain per unit volumetric power dissipation density in the active region.