Optically Controlling Broadband Terahertz Modulator Based on Layer-Dependent PtSe Nanofilms.

In this paper, we propose an optically controlling broadband terahertz modulator of a layer-dependent PtSe nanofilm based on a high-resistance silicon substrate. Through optical pump and terahertz probe system, the results show that compared with 6-, 10-, and 20-layer films, a 3-layer PtSe nanofilm has better surface photoconductivity in the terahertz band and has a higher plasma frequency of 0.23 THz and a lower scattering time of 70 fs by Drude-Smith fitting.