Integratable 40 dB optical waveguide isolators using a resonant-layer effect with mode coupling

Resonant-layer effect RLE optical isolators can be integrated with a wide variety of optical waveguide devices and systems and theoretically provide a high degree of isolation with low insertion loss. The effect of mode coupling within the isolator and the losses due to coupling between the isolator and the input and output waveguides on the performance of RLE isolators is calculated. The results predict that isolators integrated with semiconductor waveguides similar to those used for efficient lasers and amplifiers and isolators integrated with quartzlike waveguides can give 40 dB of isolation with insertion losses below 3 dB. The calculations also show relaxed dimensional tolerance and lengths in the 1–2 mm range, which makes commercial production of such isolators attractive. © 2006 American Institute of Physics. DOI: 10.1063/1.2388040