High-performance interband cascade lasers emitting between 3.3 and 3.5 microns

Abstract

Semiconductor laser performance in the 3 to 4 micron wavelength region has lagged behind lasers at longer and shorter wavelengths. However, recent advances by the group at the Naval Research Laboratory (NRL) have markedly changed this situation, and in a recent collaboration with the NRL group, we demonstrated high performance interband cascade lasers at 3.8 microns. In this work, we present results extending this earlier work to shorter wavelengths. In particular, we designed four new interband cascade lasers at target wavelengths between 3.3 and 3.5 microns. Initial testing of broad area devices show threshold current densities of ~230 A/cm² at 300K, almost a factor of two lower than the ~425 A/cm² results obtained on the broad area devices at 3.8 microns. In this paper, we present performance data on these broad area lasers and also data on narrow ridge devices fabricated from the same material.