Single-mode isolator in integrated optics

A multilayer structure forming a single-mode integrated optical isolator is analyzed with special emphasis on the dimensional conditions to be fulfilled in order to match the device with single-mode optical fibers optically used in coherent communication systems. A magnetooptical layer is included just below the active one in order to improve the performance of the isolator. The fundamental mode behavior in the multilayer guide is investigated. The mode propagation in the guide in an external magnetic field with Faraday configuration is also studied, and it is shown that the performance of the device improves with higher specific Faraday rotation of the substrate