Faraday polarisation mode conversion in semiconductor waveguides incorporating periodic garnet claddings

We report on our progress towards the integration of nonreciprocal optical elements in, for example, an integrated optical waveguide isolator on conventional semiconductor photonic platforms. Our approach uses an evanescent interaction with a magneto-optic iron garnet upper cladding. Specifically, cerium- and bismuth- substituted yttrium and terbium iron garnets were investigated. Device fabrication incorporates RF sputtering, mask lift-off to form a grating for a quasi-phase-matched interaction and thermal anneal. A non-reciprocal polarisation-mode conversion was observed.