InAs-based distributed feedback interband cascade lasers

Single mode emission of InAs-based interband cascade lasers using lateral metal gratings that provide distributed feedback is presented. A double ridge configuration was developed, where the grating is placed above the active region while a second, slightly wider ridge ensures current confinement in the active region. Side mode suppression ratios above 30 dB have been obtained, and single mode emission was observed at wavelengths around 6 μm in continuous-wave operation up to a temperature of −10 °C. Current- and temperature-tuning rates of 0.011 nm/mA and 0.50 nm/ °C, respectively, have been found, and a total tuning range of 6.5 nm has been covered by one device. As a reference, ridge waveguide devices without a grating made from the same material were able to emit in pulsed mode up to 49 °C and in continuous-wave operation at temperatures up to 0 °C around 6 μm.