| 摘要 |
<p>PURPOSE:To make an apparatus compact and to obtain high sensitivity by splitting linearly polarized light, introducing the lights into modulating waveguides, imparting phase modulation corresponding tot he strength of an electromagnetic field, reflecting the lights, making the lights advance in the reverse direction, and detecting the lights through a polarization beam splitter. CONSTITUTION:The laser light, which is emitted from the semiconductor laser of a measuring- light generating part 70 and polarized in the direction Z, passes through a polarization beam splitter (PBS) 80. The plane of polarization is rotated by 45 degrees. The light is cast into a sensor part 50 through a polarizer 84, a lens 86 and an optical fiber 88. The light is split through a splitting and synthesizing part 60 of a luminous-intensity modulating part 66 through an incident end 56 and a waveguide 58. During the propagation in modulating waveguides 58a and 58b, the measuring lights undergo phase modulations corresponding to the magnitudes of voltages applied on electrodes 64a and 64b, i.e. the strengths of an electromagnetic field in a measuring field 100 which are detected with antennas 52a and 52b. The phase-modulated measuring lights are reflected from a reflecting surface and made to advance in the reverse direction. The lights are reflected from the PBS 80 and cast into photodetector 74. The output signal is processed in a signal processing circuit 76, and the strength of the electromagnetic field is displayed on a display device 78.</p> |
