Terahertz Strong-Field Physics in Light-Emitting Diodes for Terahertz Detection and Imaging
Abstract
Intense terahertz (THz) electromagnetic fields have been utilized to reveal a variety of extremely nonlinear optical effects in many materials through nonperturbative driving of elementary and collective excitations. However, such nonlinear photoresponses have not yet been discovered in light-emitting diodes (LEDs), letting alone employing them as fast, cost effective,compact, and room-temperature-operating THz detectors and cameras. Here we report ubiquitously available LEDs exhibited gigantic and fast photovoltaic signals with excellent signal-to-noise ratios when being illuminated by THz field strengths >50 kV/cm. We also successfully demonstrated THz-LED detectors and camera prototypes. These unorthodox THz detectors exhibited high responsivities (>1 kV/W) with response time shorter than those of pyroelectric detectors by four orders of magnitude. The detection mechanism was attributed to THz-field-induced nonlinear impact ionization and Schottky contact. These findings not only help deepen our understanding of strong THz field-matter interactions but also greatly contribute to the applications of strong-field THz diagnosis.
Cite
@article{arxiv.2007.14093,
title = {Terahertz Strong-Field Physics in Light-Emitting Diodes for Terahertz Detection and Imaging},
author = {Chen Ouyang and Shangqing Li and Jinglong Ma and Baolong Zhang and Xiaojun Wu and Wenning Ren and Xuan Wang and Dan Wang and Zhenzhe Ma and Tianze Wang and Tianshu Hong and Peidi Yang and Zhe Cheng and Yun Zhang and Kuijuan Jin and Yutong Li},
journal= {arXiv preprint arXiv:2007.14093},
year = {2020}
}