The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 08, 1997
Filed:
May. 04, 1995
Kabushiki Kaisha Toshiba, Kanagawa-ken, JP;
Abstract
An apparatus for measuring a temperature distribution along an optical fiber, comprises a light source for inputting pulsed-light into the optical fiber, an optical filter for receiving backward Raman-scattered light from the optical fiber and extracting anti-Stokes' light and Stokes' light, an optical attenuator for attenuating the intensity of the Stokes' light extracted by the optical filter, first and second signal paths each of which includes a light-receiving element and an analog-to-digital converter, a signal processor for calculating a temperature distribution along the optical fiber on the basis of the first and second signal paths, and an optical switch having a first input port for receiving the anti-Stokes' light, a second input port for receiving the Stokes' light, a first output port, and a second output port, the optical switch transmitting the anti-Stokes' light and the Stokes' light to the first output port and the second output port in a first switching position and transmitting the Stokes' light and the anti-Stokes' light to the first output port and the second output port in a second switching position.