InAlAs/InGaAs-MSM photodetectors based on optical cavity using metallic mirrors: THz frequency operation, high quantum efficiency and high saturation current

We present a metallic mirror-based resonant cavity-enhanced InAlAs/InGaAs metal-semiconductor-metal (InAlAs/InGaAs-MSM) photodetector driven by a 1550 nm wavelength illumination. The device shows a quantum efficiency higher than 30%, a cut-off frequency higher than 100 GHz, and a saturation current density above 40 kA/cm2. As a proof of concept, we demonstrate the generation of 0.25 mW of continuous wave output power at a frequency of 100 GHz via the photomixing of an optical beatnote. This result underlines the potential of InAlAs/InGaAs-MSM for subterahertz and terahertz optoelectronic applications driven by telecom lasers.