Patent ID: 6794635
Filing Date: 2004-09-21
Classification: G01J,G01N

Abstract:
An apparatus for detecting an amount of depolarization of a linearly polarized beam transmitted by a birefringent medium, comprising:a first beam splitter for separating a first portion of the transmitted beam into first orthogonal components; a first set of at least two photodetectors for detecting a respective one of the first orthogonal components separated by said first beam splitter; a second beam splitter for separating a second portion of the transmitted beam into second orthogonal components, said second beam splitter being disposed off-axis of the incident linearly polarized beam; a second set of at least two photodetectors for detecting a respective one of the second orthogonal components separated by said second beam splitter; and a subtracting device connected to said first set of at least two photodetectors and to said second set of at least two photodetectors, said subtracting device subtracting signals received by said second set of at least two photodetectors from respective signals received by said first set of at least two photodetectors.