Recent advances of low-dimensional materials in Mid- and Far-infrared photonics

Since the mid- (2-20 mu m) and far-infrared (20-1000 mu m) regions cover the vibration and rotation characteristic "fingerprint" spectra of many gas molecules and three atmospheric transmission windows (2-2.5 mu m, 3.5-5 mu m and 8-14 mu m), the mid- and far-infrared pulsed laser sources and novel photonic devices have been widely applied, such as molecular spectroscopy, materials processing, gas sensing, free-space communications, and medicine. Low-dimensional materials exhibit great potential in mid- and far-infrared pulsed laser and photonic devices because of their high third-order nonlinear coefficient, ultrafast carrier dynamics, and excellent optics and electricity properties. However, relatively little is known of low-dimensional materials-based mid- and far-infrared photonics, and a review of the fabrication and properties of low-dimensional materials in mid- and far-infrared photonics has not been reported. In this contribution, this review starts with an introduction to the synthesis and optical response of low-dimensional materials. In the following sections, the developments of low-dimensional materials-based mid- and far-infrared photonics are comprehensively summarized, including pulsed lasers, optical modulators, and photodetectors. Finally, perspectives and challenges regarding the design of low-dimensional materials-based photonics are provided. (C) 2020 Published by Elsevier Ltd.