摘要 |
<p>The present invention relates to an apparatus and a method for detecting an amount of depolarization of a linearly polarized beam transmitted by a birefringent medium in the direction of the optical axis thereof. The apparatus comprises a first beam splitter (7) for separating an non-axis portion (2) of said linearly polarized beam into the orthogonal components (3, 4), two photodetectors (8, 9) for detecting each components (3, 4), a second beam splitter (12) for separating an off-axis portion (11) of said linearly polarized beam into the orthogonal components (15, 16), wherein said second beam splitter (12) is disposed off-axis of the incident linearly polarized beam (1), a second set of photodetectors for detecting the components (15, 16) separated by said second beam splitter (12), and subtracting device (17) for subtracting the signals received by the second set of photodetectors (13, 14) from the respective signals received by the first tow photodetectors (8, 9).</p> |