Physica Scripta
A compact magnetic-free optical isolator
De-Kang Chai, Jiangbin Zheng, G N Chen, Zhu-Bo Wang, Yan-Lei Zhang, Chun‐Hua Dong, Chang‐Ling Zou, Guo G, Ming-Yong Ye, Gong-Wei Lin, 林秀敏 LIN Xiu-min
Abstract
Abstract Current commercial optical isolators (OIs) primarily rely on the Faraday effect in magneto-optical materials, which necessitates the use of external magnetic fields. Here, we report a passive OI constructed from compact, commercially available optical components and an atomic vapor cell, which does not require a biasing magnetic field or any external drive, and only requires that the intensity of the forward beam is higher than that of the backward beam, which is very easy to satisfy in isolator applications. Operating at 795 nm, this device uses the principle of nonlinear non-reciprocity to achieve a bandwidth of 6 GHz and an isolation ratio greater than 30 dB.