文献类型：期刊文献

英文题名：Magnetic-free unidirectional polarization rotation and free-space optical isolators and circulators

作者：Liu, Lifeng[1,2];Zhang, Ying[1,2];Zhang, Shicheng[1];Qian, Jun[1];Gong, Shangqing[1,3];Niu, Yueping[1,4]

机构：[1]East China Univ Sci & Technol, Sch Phys, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Sch Mat Sci & Engn, Shanghai 200237, Peoples R China;[3]Shanghai Engn Res Ctr Hierarch Nanomat, Shanghai 200237, Peoples R China;[4]Shanghai Frontiers Sci Ctr Optogenet Tech Cell Met, Shanghai 200237, Peoples R China

年份：2022

卷号：121

期号：26

外文期刊名：APPLIED PHYSICS LETTERS

收录：;EI(收录号：20230113344771);WOS:【SCI-EXPANDED(收录号:WOS:000905379800003)】；

基金：This work is supported by the National Natural Science Foundation of China (Grant Nos. 11974109, 11874146, 12034007, and 12004112) and the Shanghai Natural Science Foundation (Grant Nos. 21XD1400700 and 20YF1410800).

语种：英文

外文关键词：Optical communication - Q factor measurement - Rotation - Signal processing

摘要：Optical nonreciprocity is an essential concept in optical signal processing and communication. The traditional way to achieve nonreciprocity is using magneto-optical nonreciprocal polarization rotation, which is incompatible with existing on-chip integration due to the applied magnetic field. Here, we theoretically and experimentally realize unidirectional polarization rotation with a magnetic-free mechanism using atomic ensembles. Free-space isolators and circulators are further formed based on the nonreciprocity of polarization rotation. As only one direction of the signal changes its polarization, the forward transmission and backward isolation can be adjusted separately. Compared with the existing magnetic-free circulators that rely on high-Q factor cavities or Mach-Zehnder interferometers, we experimentally realized circulators in free space. This dramatically simplifies the magnetic-free circulator structure and provides better stability. Published under an exclusive license by AIP Publishing.