High-speed mid-wave infrared interband cascade photodetector at room temperature

Opt Express. 2020 Nov 23;28(24):36915-36923. doi: 10.1364/OE.409868.

Abstract

High-speed mid-wave infrared (MWIR) photodetectors have important applications in the emerging areas such high-precision frequency comb spectroscopy and light detection and ranging (LIDAR). In this work, we report a high-speed room-temperature mid-wave infrared interband cascade photodetector based on a type-II InAs/GaSb superlattice. The devices show an optical cut-off wavelength around 5 µm and a 3-dB bandwidth up to 7.04 GHz. The relatively low dark current density around 9.39 × 10-2 A/cm2 under -0.1 V is also demonstrated at 300 K. These results validate the advantages of ICIPs to achieve both high-frequency operation and low noise at room temperature. Limitations on the high-speed performance of the detector are also discussed based on the S-parameter analysis and other RF performance measurement.