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:
Jun. 17, 2008
Filed:
Jan. 30, 2007
Masaki Ogura, Hitachi, JP;
Masahiko Kobayashi, Hitachi, JP;
Hidetaka Kawauchi, Hitachi, JP;
Juhyun Yu, Hitachi, JP;
Masaki Ogura, Hitachi, JP;
Masahiko Kobayashi, Hitachi, JP;
Hidetaka Kawauchi, Hitachi, JP;
Juhyun Yu, Hitachi, JP;
Hitachi Cable Ltd., Tokyo, JP;
Abstract
An optical fiber temperature sensor has a sensing part composed of an optical fiber arranged at a temperature measurement point; a light source for injecting a light to the sensing part; a wavelength filter module for branching the Raman scattered light from the back scattered light generated at the sensing part; photoelectric detectors for detecting the Raman scattered light and a signal processing circuit for processing the electric signals from the photoelectric detectors, wherein the light source is a semiconductor laser having a wavelength bandwidth of 0.78 μm; the wavelength filter module has a longer wavelength side band pass filter for transmitting the Stokes light and a shorter wavelength side band pass filter for transmitting the anti-Stokes light; and the longer wavelength side band pass filter and the shorter wavelength side band pass filter do not allow the light having the wavelength band of the semiconductor laser to be transmitted.