Surface-plasmon distributed-feedback mid-infrared quantum cascade lasers based on hybrid plasmon/air-guided modes

We demonstrate pulsed, room-temperature operation of single-mode surface-plasmon distributed-feedback quantum cascade lasers operating at lambdaap7.5 mum. The grating is implemented via the sole patterning of the top metallic contact. The presence of the grating yields an important loss reduction with respect to unpatterned surface-plasmon devices.