Twisted black phosphorus-based van der Waals stacks for fiber-integrated polarimeters.

Xiong, Yifeng; Wang, Yushu; Zhu, Runze; Xu, Haotian; Wu, Chenhui; Chen, Jinhui; Ma, Yang; Liu, Yuan et al. · Sci Adv · 2022

basic_science · Level V

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Abstract

The real-time, in-line analysis of light polarization is critical in optical networks, currently suffering from complex systems with numerous bulky opto-electro-mechanical elements tandemly arranged along the optical path. Here, we design and fabricate a fiber-integrated polarimeter by vertically stacking three photodetection units based on six-layer van der Waals materials, including one bismuth selenide (Bi<sub>2</sub>Se<sub>3</sub>) layer for power calibration, two twisted black phosphorus (BP) layers for polarization detection, and three hexagonal boron nitride (hBN) layers for encapsulation. The self-power-calibrated, self-driven, and unambiguous detection of both linearly polarized (LP) and circularly polarized (CP) light is realized by the broken symmetry-induced linear photogalvanic effects (LPGEs) and circular photogalvanic effects (CPGEs) in the two BP units. Moreover, the device enables single-pixel polarimetric imaging to acquire spatial polarization information. The ultracompact device structure, free from external optical and mechanical modules, may inspire the development of miniaturized optical and optoelectronic systems.