Opt Express. 2023 Feb 27;31(5):8375-8383. doi: 10.1364/OE.482805.
The integrated optical isolator is an essential building block in photonic integrated chips. However, the performance of on-chip isolators based on the magneto-optic (MO) effect has been limited due to the magnetization requirement of permanent magnets or metal microstrips on MO materials. Here, an MZI optical isolator built on a silicon-on-insulator (SOI) without any external magnetic field is proposed. A multi-loop graphene microstrip operating as an integrated electromagnet above the waveguide, instead of the traditional metal microstrip, generates the saturated magnetic fields required for the nonreciprocal effect. Subsequently, the optical transmission can be tuned by varying the intensity of currents applied on the graphene microstrip. Compared with gold microstrip, the power consumption is reduced by 70.8%, and temperature fluctuation is reduced by 69.5% while preserving the isolation ratio of 29.44 dB and the insertion loss of 2.99 dB at1550 nm.
集成光隔离器是光子集成芯片中的基本组成部分。然而，基于磁光（MO）效应的片上隔离器的性能受到 MO 材料上永磁体或金属微带的磁化要求的限制。这里提出了一种在绝缘体上硅（SOI）上构建的无任何外加磁场的 MZI 光隔离器。多环石墨烯微带作为波导上方的集成电磁体，而不是传统的金属微带，产生了非互易效应所需的饱和磁场。随后，可以通过改变施加在石墨烯微带上的电流强度来调节光传输。与金微带相比，在 1550nm 时，该结构的隔离比为 29.44dB，插入损耗为 2.99dB，同时功耗降低了 70.8%，温度波动降低了 69.5%。
