| 摘要 |
<p>PURPOSE:To improve the temperature characteristic of an optical measuring instrument by phase-modulating two polarized components intersecting with each other orthogonally through optically effective elements which produce double refraction whose longer principal axes of refractive index ellipsoids are different from each other by 90 deg. and then, fetching and multiplexing polarized components in the same direction by means of a polarizer. CONSTITUTION:Among the rays of light dicomposed into two straight polarized lights whose planes of polarization intersect with each other orthogonally by means of a PBS 4, the 1st rays 22 are reflected by a total-reflecting mirror 15 and made incident on an electrooptic element 16. The 2nd rays 23 are made incident on another electrooptic element 17. The electrooptic elements 16 and 17 are provided in such a way that angles of 90 deg. can be formed between their crystal axes around the optical axis and, moreover, voltages to be measured in the same direction are respectively applied across the electrooptic elements 16 and 17. The rays 22 and 23 are made incident on an 1/4-wave plate 5 and optical biases are given to them. Then the rays 22 and 23 are respectively passed through PBSs 18 and 19 and changed to optical intensity modulation. The rays of light multiplexed by means of a multiplexer 21 and led to a light condenser 10 through an optical fiber 9 are fetched as output signals after photoelectric conversion and signal processing similar to conventional one is performed.</p> |
