| 摘要 |
<p>PURPOSE:To enable measurement at a high response characteristic by enabling the noise component of light input to an optical fiber from a light source to be eliminated, enabling detection using an optical fiber sensor at high accuracy, and eliminating the necessity of passing a detection signal from the optical fiber sensor through a band-pass filter. CONSTITUTION:Part of light input to an optical sensor portion 1 from a light source 8 is separated by a polarizer 2, guided to a monitoring light receiver 18 by means of an optical fiber 6, amplified by a light-receiving amplifier 19, and input to a comparator 11. The comparator 11 outputs a level difference between the output of a reference voltage generator 12 which generates a driving reference voltage and the output of the light-receiving amplifier 19; to set this output to zero, a light-source driving level control portion 10 outputs an appropriate voltage to a light source driving portion 9, which in turn controls the output level of the light source 8. A detection signal from the optical sensor portion 1 is received by the light receiver 14 of a signal detecting system.</p> |
