Nonreciprocal Propagation Characteristics of YIG Thin Film

The characteristics of an optical nonreciprocal phase shifter, with which optical circulators can be constructed, are investigated. We have measured the nonreciprocal phase shift of an appropriately magnetized yttrium iron garnet (YIG) thin film and thus confirmed experimentally that an AIR/YIG/GGG structure can function as an optical nonreciprocal phase shifter.