All dielectric integrable optical isolators

On-chip optical isolators, functioning as unidirectional gates for light, play a crucial role in maintaining signal integrity, preventing laser destabilization, and fortifying the overall performance of optical systems. In this paper, we propose a five-layered heterostructure consisting of a magneto-optic material sandwiched between parallel dielectric slab waveguides. Under TMOKE configuration, the coupled optical modes undergo an electromagnetic profile transformation that can be harnessed to confine the input mode in one waveguide during forward propagation and in the other during backward propagation. Together with radiative subwavelength gratings, such a system can provide a 20dB isolation ratio with negligible insertion losses.