TEMPERATURE MEASUREMENT BY ANTI-STOKES RAMAN SPECTROSCOPY

PURPOSE:To obtain a handy and effective optical meter, by making two first beams cross each other in a measuring area as separated in stead of overlapping them. CONSTITUTION:The temperature of a combustion flame is measured by anti- Stokes Ramans method. At this point, laser lights with two different kinds of frequencies, omega1 and omega2 (omega1>omega2) produced to irradiate non-measuring material are supplied from a YAG laser 1 and a dye laser 2. These lights are transmitted through independent optical paths to a measuring position without being mixed together while being partially cut off with beam stops 10 and 11 but the cut faces thereof are made to oppose each other with a dichroic mirror 16 while the lights are sent to a convex lens 17 as two parallel beams close to each other. The two beams are so arranged to cross each other in a combustion cylinder 18 and after checked for the generation of an anti-Stokes light, the interval thereof is adjusted by moving a prism 9. Thereafter, the two beams are removed with a dichroic mirror 20 and thus, the anti-Stokes light is converted into an electrical signal with a photodetector through a spectroscope 23.