Compact Optical Isolator Research Articles

A compact optical isolator using a Y3Fe5O12 crystal for near infra-red radiation

Using a Y3Fe5O12 crystal as a Faraday rotator material, a samarium cobalt permanent magnet and two iron yokes, a compact optical isolator was constructed at 1.153μm for optical transmission systems. The developed isolator is 13 mm in diameter and 25 mm in length, including two polarizers. The isolator characteristics are 1.3 dB forward loss and greater than 30 dB backward loss. A broadband isolator is realized by inserting a 45 degree Faraday rotator and an optically active 45 degree quartz rotator between the two polarizers set at 90 degrees in relation to each other.

Compact optical isolator for near-infrared radiation

Compact Faraday rotation isolators have been developed for near-infrared radiation. Two types of Faraday rotators were used: one was composed of two permanent magnets, the other of a closed magnetic circuit with a permanent magnet. 2.0 dB insertion loss and 30 dB isolation ratio at 1.15 ?m wavelength have been obtained.