| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide the polarization-independent-type physical-quantity measuring method without the polarization dependence by the disturbance such as temperature change. SOLUTION: The modulation of the polarization state of the propagating light in an optical fiber is performed at least at one of the side of a light source 4 and the side of a detecting part 14. In a physical-quantity sensor, which measures a magnetic field, an electric field and the like in this way, the azimuth of the polarization surface of the propagating light in the optical fiber and the phase between two optical axes are modulated by a frequency fs (a light- source side frequency is fs1 and a detecting-part-side frequency is fs2 ) at both sides or one of the side of the light source 4 and the side of the detecting part 14. Thus, the spectral intensity signals such as the central frequency fs1 or fs2 (fs1±fs2 or (fs2±fs1 )) or the like is detected. Thus, information can be detected stably without depending on the change in polarization state of the propagated light.</p> |
