Patent ID: 7145661

Claim:
An optical coherence tomography (OCT) system comprising: an interferometer having a reference arm and a sample arm each having an optical path, the sample arm being disposed such that a test sample reflects a sample portion R S of an incident optical signal S S along the sample arm optical path; a reflector disposed in the reference arm to reflect a reference portion R R of an incident optical signal S R along the reference arm optical path; a source for producing an optical source signal S having a short coherence length and a first polarization state; a polarizing beam splitter disposed to direct portions of the optical source signal S along the reference arm optical path and the sample arm optical path; a first polarizing element disposed to select, from the returning reference and sample portions (R R +R S ), a detector component S D having a second polarization state, wherein the orientation of the first polarizing element with respect to the orientation of the beam splitter is selected to transmit about ninety-five percent of the returning sample portion R S and about five percent of the returning reference portion R S ; and a detector disposed to produce an output signal V D representing the optical signal intensity I D of the detector component S D , wherein the second polarization state is related to the first polarization state such that the detector operates in a noise-optimized regime.