On-Chip Metasurface-Mediated MoTe2 Photodetector with Electrically Tunable Polarization-Sensitivity

Abstract

Photodetectors with tunable polarization sensitivity play a significant role in decoding signals in optical communications, extracting polarization-encrypted information, and the environmental monitoring of polarization variations. Metasurfaces are widely used in polarized photodetectors, while the responses for different polarization incidences follow a determinable and consistent correspondence. In this paper, an electrically tunable polarization photodetector composed of MoTe₂ and gold metasurface is proposed for on-chip polarization-sensitive near-infrared (900–1200 nm) detection. Through contact engineering and electro-tuning, highly-tunable Schottky barriers are achieved. This enables the modulation of photoelectric conversion via the excitation of surface plasmon polaritons, which in turn allows for continuous adjustment on the degree of linear polarization of a settled metasurface ranging from 0.2 to an ultimate value of 1.0. The results outline a paradigm to achieve a polarization-dependent electrically tunable response, which is promising for on-chip information processing in integrated optics.