Optics: measuring and testing – Optical pyrometers – With sample engaging rod or tube
Patent
1994-07-21
1997-01-07
McGraw, Vincent P.
Optics: measuring and testing
Optical pyrometers
With sample engaging rod or tube
25022718, 356 731, 356301, G01N 2165, G01J 506
Patent
active
055922821
ABSTRACT:
Optical time domain reflectometry methods and apparatus are proposed in which the back-scattered optical radiation used to produce output signals is restricted to that resulting from Rayleigh scattering of light launched into a fiber 2 at a first wavelength and that in an anti-Stokes spectral band resulting from Raman or Brillouin scattering of optical radiation at the first wavelength. A first set of output signals produced in dependence upon the anti-Stokes back-scatter may be normalized to the geometric mean of a second set of output signals, produced in dependence upon the Rayleigh back-scatter at the first wavelength, and a third set of output signals, produced in dependence upon Rayleigh back-scatter resulting from light launched into the fiber at the anti-Stokes wavelength. Growth in the intensity of optical radiation in a first Stokes (Raman or Brillouin) spectral band may be inhibited, so as to suppress stimulated scattering, for example by making the fiber 2 high loss at the Stokes wavelength and/or launching into the fiber 2, simultaneously with the pulse at the first wavelength, an additional pulse at a third wavelength equal to that of a Stokes spectral line resulting from inelastic scattering of optical radiation at the first Stokes wavelength. The first wavelength may be chosen so as to minimize the transmission loss, in view of the average losses at the first and detected wavelengths or the increase with wavelength of the launch power which can be used before stimulated scattering has a specified effect.
REFERENCES:
patent: 4859065 (1989-08-01), Bibby
patent: 5217306 (1993-06-01), Wada
Conference on Lasers and Electro-Optics, 1990 Technical Digest Series, vol. 7 (Summary of article "Long Distance Distributed Temperature Sensor" pp. 460, 461 by Wada et al. ).
McGraw Vincent P.
York Limited
LandOfFree
Suppression of stimulated scattering in optical time domain refl does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Suppression of stimulated scattering in optical time domain refl, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Suppression of stimulated scattering in optical time domain refl will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1769127