Title:
WAVELENGTH MEASURING INSTRUMENT
Document Type and Number:
Japanese Patent JP3669473
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To increase the number of wavelength measurement points (sensors) of the wavelength measuring instrument.
SOLUTION: This wavelength measuring instrument guides the light from a wide-band light source to Bragg diffraction gratings through an optical fiber, makes reflected lights from the Bragg diffraction gratings on an array waveguide diffraction grating, and measures the wavelengths of the reflected lights from the logarithm of the ratios of photocurrents generated by couples of photodetecting elements provided at output channels of the array waveguide diffraction grating. In this case, 1st and 2nd optical filters 22 and 23 are interposed as a filter means between the Bragg diffraction gratings FBG1 to FBG4 and the array waveguide diffraction grating(AWG) 25 of a measurement part 1B and the transmitted lights of the filters 22 and 23 are made incident on the array waveguide diffraction grating 25 by turns.
Inventors:
Noriyuki Hirayama
Anichi Sano
Anichi Sano
Application Number:
JP9251099A
Publication Date:
July 06, 2005
Filing Date:
March 31, 1999
Export Citation:
Assignee:
Fuji Electric Systems Co., Ltd.
International Classes:
G01L1/24; G01B11/16; G01J1/02; G01J3/18; G01J9/00; G01K11/12; (IPC1-7): G01J3/18; G01B11/16; G01J9/00; G01K11/12; G01L1/24
Domestic Patent References:
| JP8506185A | ||||
| JP8251105A |
Foreign References:
| WO1998036252A1 |
Attorney, Agent or Firm:
Yuichi Morita
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