Patent ID: 7782532

Claim:
An optical isolator, comprising: a first birefringent material comprising a surface configured to receive a forward light propagating in a forward direction and to receive a backward light propagating opposite to the forward direction, wherein the first birefringent material has an optical axis at about 45 degree angle relative to the surface, wherein the forward light has a first polarization aligned perpendicular to the optical axis and is configured to travel through the first birefringent material as an ordinary ray substantially along the forward direction, wherein at least a portion of the backward light has a second polarization not perpendicular to the optical axis, wherein the at least a portion of the backward light travels substantially as an extraordinary ray in the first birefringent material, wherein the first birefringent material is configured to displace the backward light to form a first displaced backward light, wherein the first displaced backward light is separated by about 10-40 microns from the forward light; a Faraday rotator configured to rotate the forward light by a predetermined angle along a rotation direction, wherein the Faraday rotator is configured to rotate the backward light or the first displaced backward light by substantially the same predetermined angle along the rotation direction; and an optical blocker configured to block the first displaced backward light.