Reduction of the temperature dependence of the nonreciprocal effect of magneto-optic channel waveguides

摘要

The nonreciprocal effect is the difference △β = β_(forward) - β_(backward) between forward and backward-propagation constants of optical modes. This effect is analyzed for the fundamental TM_(oo) mode of channel waveguides in epitaxially grown magnetic garnet films. To increase |△β|, double layers with opposite signs of Faraday rotation are used to prepare the waveguides. It is shown that the temperature dependence of △β can be reduced considerably if the layer with positive Faraday rotation, which is at room temperature close to the Curie point, is replaced by a paramagnetic layer with negligible, Faraday rotation. Concurrently, however, |△β| is decreased by ～35% at 295 K.