A bi-functional quantum cascade device for same-frequency lasing and detection

We demonstrate a bi-functional quantum cascade device that detects at the same wavelength as it coherently emits. Our fabricated device operates at room-temperature with a pulsed peak power emission of 45 mW and a detector responsivity of 3.6 mA/W. We show how to compensate the intrinsic wavelength mismatch between the laser and the detector, based on a bound-to-continuum design. An overlap between the laser and the detector spectra was observed from 6.4 μm to 6.8 μm. The electro-luminescence spectrum almost perfectly matches the detector spectrum, overlapping from 6.2 μm to 7.1 μm.