Optically-Pumped Mid-Infrared Interband Cascade Lasers

Radiative output has been observed from unbiased, optically-pumped interband cascade lasers. Results are presented for two different samples with emission wavelengths in the 3.2-3.8 μm range. The threshold pump intensity is reduced and the slope efficiency enhanced for longer optical pumping wavelengths, with a maximum achieved operating temperature of 200 K. Optically-pumped samples exhibit a blue shift of 80-150 nm when compared to electrically-injected devices fabricated from the same wafer.