| 摘要 |
PURPOSE:To improve precision by arranging a surface acoustic wave element which forms an oscillation circuit across the phase shifting part of a branch interference type light guide body, and imposing intensity modulation upon light transmitted to an input part and outputting the modulated light. CONSTITUTION:Phase modulation is imposed upon light passed through the phase shifting part 22 of the branch interference type light guide body 20 with the compressional wave of a surface acoustic wave and the intensity-modulated light is outputted from an end part of the coupling part 23 of the branch interference type light guide body 20. The intensity-modulated light becomes a digital signal and a high-precision digital measurement is taken without any influence of output variation of an optical fiber and a light source. |
