Monolithically-integrated mid-infrared interband cascade lasers and photodetectors (Conference Presentation)

Abstract

The family of interband cascade (IC) IR devices includes: interband cascade lasers (ICLs), interband cascade IR photodetectors (ICIPs), and thermophotovoltaics (ICTPVs). To date, developments at the component level have resulted in power-efficient mid-IR ICLs with CW operation at room temperature and above as well as uncooled mid-IR low-noise and high-speed ICIPs. However, there has been little effort to integrate these devices on a single chip for an IR photonic system. Since an appropriately designed ICL can operate as an IR photodetector at zero bias, ICLs and ICIPs can be grown and fabricated on a single chip, enabling the on-chip integration of IR lasers and photodetectors for mid- and long-IR wavelengths. We report the first demonstration of monolithically integrated mid-IR IC devices operating at room temperature. The unit consists of a monolithically integrated ICL and ICIP fabricated using focused ion beam (FIB) milling. The base structure is a type-I ICL with quaternary GaInAsSb active regions. The laser peak emission wavelength is 3.1 μm at 20 ◦C and the 10% cut-off wavelength of the corresponding ICIP is 3.3 μm, which ensures sufficient photon absorption at the lasing wavelength. For a laser/detector unit (at 20 ◦C) with a 12 μm gap between laser mirror and detector, the open-circuit voltage of the ICIP is 1.06 V and its short-circuit current is 106 μA, resulting from the laser emission (2.6 mW/facet). These preliminary results demonstrate the practical application of integrated IC devices for high-temperature, high-bandwidth and power-efficient on-chip sensors and optical communication mid-IR photonic systems.