We design an ultracompact optical isolator with normal incident geometry that operates with a bandwidth that is substantial for a device of this size. For operation in a telecommunication wavelength of 1.55 μm, the thickness of the device is less than 1 μm and the device supports an operating bandwidth of 400 GHz over which the minimum contrast ratio exceeds 25 dB. Our design utilizes guided resonance in a photonic crystal slab to enhance magneto-optical effects, and exploits interference effects among multiple resonances to create desired transmission spectral line shapes.
© 2011 Optical Society of America
Original Manuscript: June 28, 2011
Revised Manuscript: August 16, 2011
Manuscript Accepted: September 29, 2011
Published: October 28, 2011
Kejie Fang, Zongfu Yu, Victor Liu, and Shanhui Fan, "Ultracompact nonreciprocal optical isolator based on guided resonance in a magneto-optical photonic crystal slab," Opt. Lett. 36, 4254-4256 (2011)