Generation Of Elliptically Polarized Terahertz Radiation From Black Phosphorus Crystallites

Polarized THz radiation is increasingly being investigated and applied in the new interdisciplinary field "TeraNano." We report the generation of terahertz (THz) radiation by a linearly polarized femtosecond optical pulse in black phosphorus (BP) crystallites grown by chemical vapor deposition. Characterization of THz radiation is performed by time-resolved THz spectroscopy. It was found that BP emits elliptically polarized THz radiation with an ellipticity of epsilon = 0.77 +/- 0.03. A saturation was found in the dependence of the THz intensity on the intensity of the incident optical pump for the latter higher than 6 mJ/cm(2). The results of our work can provide new fundamental knowledge needed to create detectors and generators based on BP in the THz range. (C) 2021 Society of Photo-Optical Instrumentation Engineers (SPIE)