Twisted black phosphorus–based van der Waals stacks for fiber-integrated polarimeters
Yifeng Xiong, Yushu Wang, Runze Zhu, Haotian Xu, Chenhui Wu, Jinhui Chen, Yang Ma, Yuan Liu, Ye Chen, Kenji Watanabe, Takashi Taniguchi, Mengzhu Shi, Xianhui Chen, Yanqing Lu, Peng Zhan, Yufeng Hao, Fei Xu
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 2 Se 3 ) 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.