WAVEGUIDE TYPE OPTICAL ISOLATOR

摘要

PURPOSE:To provide a waveguide type optical isolator which is small-sized and is easily connected to another waveguide type optical parts and has a small insertion loss and can be put to practical use. CONSTITUTION:A single mode waveguide type nonreciprocal mode conversion part 12 provided on the quartz glass single mode waveguide where a core part is buried in a clad layer formed on a substrate, a first mode selecting part 10 consisting of a thin plate type polarizer 14 provided on one incidence/outgoing end face side of the nonreciprocal mode, and a second mode selecting part 11 consisting of a thin plate type polarizer 14 provided on the other side are provided. Since the small-sized and small-loss thin plate type polarizer 14 is used in the mode selecting part 10, this optical isolator has the insertion loss reduced and is miniaturized as the whole in comparison with a conventional waveguide type optical isolator where a metal load type polarizer is used in the mode selecting part. This optical isolator has a three-dimensional waveguide structure and is easily connected to another waveguide type optical parts because being operated in the single mode.