A hybrid integrated waveguide isolator on a silica-based planar lightwave circuit

La and Ga substituted yttrium iron garnet single-mode buried channel waveguides, prepared using liquid-phase-epitaxial growth and Ar ion beam etching, have been successfully applied as 45 degrees nonreciprocal waveguide rotators (NRWR) for hybrid integrated waveguide isolators at lambda = 1.55 mu m. The optical and magneto-optical properties of the prepared 45 degrees NRWR's and the epitaxial films are investigated in detail. We describe the assembly procedure and present optical measurement results for the hybrid integrated waveguide isolators, The hybrid isolators are composed of a 45 degrees NRWR, a half-wave plate sheet, thin film-type polarizers, a thin plate-type permanent magnet and a silica-based waveguide on a silicon substrate. We obtained good waveguide isolators with low insertion losses (<3.2 dB) and high isolation (>25 dB) in the 1.5 mu m wavelength band.