Patent ID: 6804063
Filing Date: 2004-10-12
Classification: G02B

Abstract:
An optical interference filter comprising:a) a beam splitter for separating an incident optical beam into a first beam component and a second beam component; b) a first phase control element in optical communication with the beam splitter for receiving the first beam component, the phase control element comprising a first external reflector and having an internal end positioned a selected first optical path length from the beam splitter, wherein the first phase control element modifies the phase of the first beam component and wherein the first beam component is substantially reflected by the first phase control element; and c) a second phase control element in optical communication with the beam splitter for receiving the second beam component, the second phase control element comprising a second reflector and having an internal end positioned a selected second optical path length from the beam splitter, wherein the second phase control element modifies the phase of the second beam component and the second beam component is substantially reflected by the second phase control element; wherein the internal end of the first phase control element and the internal end of the second phase control element are located in substantially parallel planes with respect to one another, and wherein the optical arrangement is constructed and arranged such that the reflected first beam component and the reflected second beam component are coherently combined and undergo optical interference.