Thin-Film Magnetless Faraday Rotators for Heterogeneously Integrated On-Chip Optical Isolators

This article describes the processing, characterization, and transfer of 25 μm-thick by 480 μm-long iron-garnet Faraday rotator films onto semiconductor substrates. Insertion losses below 0.1dB and extinction ratios of -30 dB are achieved. No magnets are needed.