LASER WAVELENGTH MEASURING APPARATUS FOR COHERENT ANTI-STOKES RAMAN SPECTROSCOPY

摘要

PURPOSE:To measure a wavelength with high accuracy and high sensitivity without receiving the effect of the change in temp., by setting atomic and molecular spectra to the standard of a measuring wavelength. CONSTITUTION:Laser beam 5 is oscillated at a part of laser beam 2 by an oscillator 4 and superposed to the beam 2 to form a focus on a specimen 9. The coherent anti- Stokes-Raman beam 10 from the focus part and the beams 2, 5 are returned to parallel beam and the beams 2, 5 are detected by a detector 15 while the beam 10 is detected by a detector 14 and, thereafter, the beams are detected by a detector 22 in synchronous relation to the gate trigger signal of the detector 15. When laser beams are incident on a hollow cathode discharge tube 16 performing DC discharge having an atom such as neon sealed therein and a hollow glass cell 17 having a molecule such as iodine sealed therein and coincide with the absorption wavelengths of neon and iodine, the beam changing in discharge voltage of the discharge tube 16 emits fluorescent beam by galvano effect and said fluorescent beam can be measured. Therefore, by parallely performing the measurement of optical galvano effect and laser excited fluorescent beam at the same time as coherent anti-Stokes-Raman measurement, a laser wavelength can be measured with high accuracy of 1GHz or less.