Garnet films of the following compositions (Lu,Bi)3(Fe,Ga,Al)5O12 and (Tm,Bi)3(Fe,Ga)5O12 are grown by liquid-phase epitaxy on -oriented substrates of gadolinium gallium garnet. Double layers with opposite signs of Faraday rotation and single layers are prepared. Optical monomode rib waveguides are realized using such films. The nonreciprocal phase shift of the fundamental TM-Mode is studied both theoretically and experimentally at a wavelength of 1.3 \mum. The maximum nonreciprocal effect of double layer films is about 1.7 times larger than that of similar single layer waveguides. Agreement between experiments and calculations is excellent.
Norbert Bahlmann, Vasu Chandrasekhara, Andreas Erdmann, Reinald Gerhardt, Peter Hertel, Ralf Lehmann, Dirk Salz, Franz-Josef teler, Michael Wallenhorst, and Horst tsch, "Improved Design of Magnetooptic Rib Waveguides for Optical Isolators," J. Lightwave Technol. 16, 818- (1998)