Fiber Optic Spectrophone.
DEPARTMENT OF THE NAVY WASHINGTON DC
Pagination or Media Count:
The present invention relates to a novel fiber optic spectrophone device for the measurement of the optoacoustic absorption coefficients of gases under irradiation by laser sources. A gas sample, contained within a spectrophone, is irradiated with a modulated beam of radiant energy which produces an acoustic pressure wave within the gas sample at the modulation frequency having an intensity related to the degree of absorption of the beam by the gas sample. The spectrophone includes a plurality of turns of optical fiber wound about a compliant cylinder. The acoustic pressure wave is coupled by the compliant cylinder to produce changes in the optical length of the fiber in response to the intensity of the pressure wave. The changes in length of the fiber are detected by an all-fiber Mach-Zehnder interferometer which produces an output representative of the pressure wave. The interferometer includes a compensation system for compensating for the effects of environmental perturbations on the system.
- Lasers and Masers
- Atomic and Molecular Physics and Spectroscopy
- Fiber Optics and Integrated Optics