Optical isolator

Claim 1

An optical isolator comprising two polarizers, two input/output ports formed, respectively, on said two polarizers, a first optical rotator disposed between said two polarizers, said first optical rotator including a Faraday rotator and a reciprocal optical rotator and a second optical rotator, each of the first and second optical rotators respectively abutting said two polarizers and a third polarizer disposed between the first and second optical rotators, said isolator being able to perform a selected one of a plurality of isolator functions on light of at least two different wavelength bands propagating, in use, through said isolator, said isolator functions including: (a) isolating light in one of said wavelength bands and allowing light in the other one of said wavelength bands to pass between said ports in forward and reverse directions; (b) isolating light in both of said wavelength bands; (c) isolating light in one of said wavelength bands and partially isolating light in the other one of said wavelength bands; and (d) isolating light in one of said wavelength bands in a forward direction and isolating light in the other one of said wavelength bands in a reverse direction; wherein said selected one of said plurality of isolator functions is selected by selecting wavelength dispersion characteristics of said first optical rotator; and wherein said reciprocal optical rotator includes a segmented reciprocal optical rotator having at least two light receptive sections, one of said at least two light receptive sections including a transmissive medium and another of said at least two light receptive sections including optical rotating material.