Design considerations for nonreciprocal integrated optical devices

This paper is concerned with the design of nonreciprocal thin-film optical devices containing gyrotropic and anisotropic materials using one-section configurations rather than the composite cascade configurations of previous designs. The analysis is based on the transmission-matrix description of TE-TM mode coupling. Circuit configurations are presented for two typical devices; the unidirectional mode converter and the TE-TM gyrator. A discussion is also given to the deterioration of the device performance due to the film-thickness deviation from the prescribed value for the example of the unidirectional mode converter utilizing the LiIO3/YIG/GGG layered structure.