| 摘要 |
<p>PURPOSE:To make a measurable distance long to a large extent, by using a laser beam source which generates Raman scattering beam as pump beam from the exciting pulse from a pulse beam source, as a measuring beam source. CONSTITUTION:An optical fiber 7 is arranged to a temp. region to be measured and a beam splitter 5 is provided to the optical fiber 7 on the incident end side thereof and a beam source system 8 is provided to one port of the beam splitter 8 while a back scattering beam detection system 13 is provided to the other port thereof. The beam source system 8 is constituted of an optical filter 4 taking out only beam having the wavelength used in measurement among beams having various wavelengths emitted from a laser beam source 3, a sepa rate pulse beam source 2 for exciting the laser beam source 3 and a beam source driving apparatus 1 for driving the pulse beam source 2. The back scatter ing beam of the natural Raman scattering beam generated in the temp. measur ing optical fiber 7 is detected by a detection system 13 and temp. is operated in a signal processing circuit 22.</p> |
