Abstract-Mid-infrared-pumped quantum cascade structure for high-sensitive terahertz detection

Mid-infrared-pumped quantum cascade structure for high-sensitive terahertz detectionh

Yan Xie, Ning Yang, Suqing Duan, and Weidong Chu

 

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-24-14-15180

Based on multiple quantum wells, we design a pumping-detection quantum cascade structure for the detection of terahertz (THz) radiation. In the structure, carriers are first pumped by a mid-infrared (MIR) laser to an excited state, to get enough energy space for the following fast longitudinal optical (LO) phonon extraction. Within the LO-phonon extraction stair, an absorption well is designed for THz detection. Due to the establishment of LO-phonon stair extractor, carriers transport between quantum wells in picosecond range and a high responsivity for THz absorption can be obtained. We also find that doping in both MIR active well and extractor region is significant for high-speed response of the THz detection. Our design is expected to extend the high-sensitive detection of a quantum cascade photodetector from middle wave of MIR to THz region.

© 2016 Optical Society of America

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