| 摘要 |
PURPOSE:To perform a high-precise measurement by means of a simple structure, by a method wherein, according to an amount to be measured, reflection or transmitting light output of a wavelength trace laser light by a variable filter, whose reflection or transmission center wavelength changes according to an amount to be measured, and a reference wavelength resonance output of a laser light and a scale resonance output are detected. CONSTITUTION:A laser light from a wavelength trace laser power source 4 is selectively fed to photofibers 3a-3c via a photoswitch 6, and is incident on transducers 1a-1c, consisting of Fabry-Perot in which a dielectric crystal works as a medium, via mode matching optical elements 2a-2c, such as rod lens and the like. Then, a reflection light, having a wavelength corresponding to an amount to be measured, is inputted to a photo detector 10c. Meanwhile, the laser light is inputted to a count circuit 11 via a light isolator 7, a reference resonance 8, and a photo detector 10a to start counting of a scale light from a scale resonator 9 and stop the signal from the photo detector 10c. This permits the high-precise measurement by means of a simple structure. |
