High-performance optical isolator for a wide temperature range using a temperature compensated Faraday rotator

Optical measuring systems and optical communication systems often need optical isolators which have large isolation with small insertion loss and which are stable for a wide environmental temperature change. For a wavelength region from 1.3 to 1.55 µm, Y3Fe5O12 is frequently used for a Faraday rotator. However, its temperature dependence of Faraday rotation is not sufficiently small for the above application. Therefore, we developed an isolator using a Faraday rotator (Y1 7Gd1.3Fe5O12) with excellent temperature characteristics and large isolation.