Method and apparatus for performing optical measurements

摘要

A method and apparatus for performing various optical measurements is provided utilizing an optical coherence domain refrectometer (OCDR). A short coherence optical radiation source applies optical radiation through like optical paths to a sample and an optical reflector. The optical reflector is movable in accordance with a predetermined velocity profile to permit interferometric scanning of the sample, the resulting output having a Doppler shift frequency modulation. This output may be demodulated and detected to obtain desired measurements and other information. Additional information may be obtained by applying radiation from two or more sources at different wavelengths to the sample and reflector and by separately demodulating the resulting outputs before processing. Birefringent information may be obtained by polarizing the optical radiation used, by suitably modifying the polarization in the sample and reference paths and by dividing the output into orthogonal polarization outputs which are separately demodulated before processing.