FBG TYPE TRANSDUCER

PROBLEM TO BE SOLVED: To achieve the compactness of a transducer by suppressing a size increase in a ring-shaped rounding part for loosening an optical fiber in an FBG type transducer which is provided with a strain element to which an FBG (optical fiber Bragg diffraction grating) is mounted, converts a change in a physical quantity to be measured into a strain in the strain element, and detects the strain by the FBG. SOLUTION: The strain element is constituted of a circular metal band 8. When the direction of the diameter of the circle passing through a notched part 8a between the ends of the metal band 8 is the direction of an X axis, and the direction of the diameter which intersects the direction of the X axis at right angles is the direction of a Y axis, by making an external force corresponding to a physical quantity to be measured act on an input part 8b on the side opposite to the notched part 8a in the direction of the X axis, the metal band 8 is deformed into an elliptic shape having a longer diameter in the direction of the Y axis. An optical fiber 15 which forms the FBG 14 is fixed to both ends of the metal band 8 by fixing parts 15a on both sides of the FBG to extend the FBG over the notched part 8a. A part 15b which continues to the fixing parts 15a is rounded in such a way as to draw a circle along the side edge of the metal band 8. COPYRIGHT: (C)2004,JPO