| 摘要 |
<p>PURPOSE:To reduce a loss in measurement by separating Rayleigh backward scattered light and Raman scattered light, and separating the Stokes' light and anti-Stokes' light in the Raman scattered light and detecting those Stokes' light and anti-Stokes' light. CONSTITUTION:Pulse light entered into an optical fiber 25 for a sensor is made to illuminate a position to be measured and the Rayleigh backward scattered light and Raman scattered light are generated. Those Rayleight backward scattered light and Raman scattered light are separated by a polarized light separating film 223b into P and S polarized light beams, which become 180 deg. out of phase by passing through a 1st wavelength plate 23; and the S and P polarized light beams of the Raman scattered light are multiplexed by a polarizing prism 22a and separated by a polarizing prism 26b into the P and S polarized light beams, which are separated in a 180 deg. out-of-phase state by a 2nd wavelength late 27. Then the separated Stokes' light and anti-Stokes' light are passed through a polarizing prism 26a to multiple the P and S polarized light beams, so that the Stokes' light and anti-Stokes' light are detected by a Stokes' light detection part 29 and an anti-Stokes' light detection part 31. Consequently, the loss in measurement is reducible.</p> |
