To accurately detect physical quantity such as displacement, load, pressure, magnetic force, and acceleration at relatively low tension and high sensitivity, and reduce influence by temperature compensation or temperature variation with one fiber grating (FBG).
Both end parts of an optical fiber 1 on which the FBG 2 is written are fixed to first and second fixing members 3, 4. These first and second fixing members 3, 4 are fixed to an immobile member 6 in an immobile state. Physical quantity from a measuring object is applied in the direction perpendicularly crossing to the axial direction of the optical fiber 1 to a first moving member 5 fixed to the center of the optical fiber 1. The variation of the tension of the optical fiber 1 is detected as the wavelength shifting amount of reflected light or transmitted light from the FBG 2 through the expansion and contraction of the FBG 2 with a detecting means.
WATABE KIYOAKI
YAMAGA KAZUNORI
FUJITA SEIICHI
TOKYO SOKKI KENKYUSHO CO LTD
TOA SOKKI KK