High performance interband cascade lasers at 3.8 microns

An interband cascade laser design has been grown by molecular beam epitaxy using uncracked arsenic and antimony sources. Lasers were fabricated into both broad-area and narrow-ridge devices, with cavity lengths ranging between 1 mm and 4 mm. At 300K, under low-duty-cycle pulsed conditions, threshold current densities for lasers with 2-mm cavity lengths are as low as 395 A/cm2, with optical emission centered at a wavelength of ~3.82 μm at 300 K. Continuous-wave (cw) performance of the narrow-ridge devices has been achieved for temperatures up to almost 60°C. We present results of both pulsed (broad-area and ridge) and cw (ridge only) measurements on these lasers, including L-I-V, spectral, cavity-length, and Hakki-Paoli analyses.