Plasmon-Waveguide Interband Cascade Lasers Near 7.5 $\mu$ m

Broad-area plasmon-waveguide interband cascade lasers with emission wavelengths near 7.5 mu m were demonstrated at temperatures up to 121 K in continuous-wave mode. Their threshold current densities and voltages varied from 72 A/cm² and 2.1 V at 84 K to 400 A/cm² and 2.7 V at 121 K, showing very efficient use of bias voltage (e.g., voltage efficiency of about 90% at 84 K) at this long wavelength. These plasmon-waveguide lasers also operated in pulsed mode at temperatures up to 165 K with emission wavelengths near 7.6 mum and threshold current density of 1100 A/cm².