An optical isolation ratio of minus;21.1thinsp;dB at lgr;=1.55 mgr;m is obtained for a LPEhyphen;grown La and Ga substituted YIG singlehyphen;mode buried channel waveguide. Waveguides about 3 mm long endhyphen;butted to singlehyphen;mode fibers show an overall insertion loss of less than 2 dB. The Ar ionhyphen;beam etching technique using a three layered etching mask provides sufficient control of both the width (sim;4 mgr;m) and height (sim;4 mgr;m) of the core ridge. The core and cladding layers are individually grown from melts with different compositions in order to reduce stresshyphen;induced birefringence. The good reproducibility with which 45deg; waveguide rotators exhibiting a circular nearhyphen;field intensity pattern can be fabricated will enable us to realize optical integration in future systems.
展开▼
