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:
Mar. 16, 2010
Filed:
Nov. 24, 2006
Kazuo Hotate, Tokyo, JP;
Kwang Yong Song, Tokyo, JP;
Kazuo Hotate, Tokyo, JP;
Kwang Yong Song, Tokyo, JP;
The University of Tokyo, Tokyo, JP;
Yokogawa Electric Corporation, Tokyo, JP;
Abstract
A measurement range is extended while maintaining the spatial resolution high by completely separating the increment of a probe light from noises. Modulations are performed on both probe light and pump light to differentiate both lights. Using the modulations, only the change in the probe light necessary for measuring the characteristic of a measurement-target optical fiber FUT can be separated. Accordingly, unlike the conventional technology, an optical wavelength filter becomes unnecessary. Further, in a case where an amplitude Δf of the frequency modulation of a light sourceis made wide to some extent to make the measurement range wide while maintaining a spatial resolution Δz high, the amplitude Δf does not affect to detection of the change in the probe light. Therefore, the increment of the probe light can be completely separated from noises, thereby extending the measurement range while maintaining the spatial resolution Δz high.