Optical circulator

Abstract

A four-port optical circulator has two planar lightwave circuit polarisation beam splitters (40, 54). Two ports of the circulator are formed by two input ports (32, 36) of the first splitter (40). The two other ports of the circulator are formed by two input ports (34, 38) of the second splitter (56). The circulator further has an assembly of a wave plate (46) and a Faraday rotator (48). A first light path through this assembly connects a first output port (42) of the first splitter (40) and a first output port (50) of the second splitter (54). A second light path through the assembly connects a second output port (44) of the first splitter (40) and a second output port (52) of the second splitter (54). The circulator is easy to integrate into a planar lightwave circuit. It may also be used as isolator.

Dependencies are inferred from the claim text.