Patent ID: 7218816

Claim:
An optical fiber grating part comprising: an elongated pedestal; a base plate installed on said pedestal, and having a different coefficient of linear thermal expansion from said pedestal; and an optical fiber passing through said pedestal, and connected to connection points installed on said pedestal and said base plate located apart from each other in the longitudinal direction of said pedestal, and having an optical fiber grating located between said connection points, wherein a predetermined tensile force is added to said optical fiber grating, and said pedestal and said base plate thermally expand or thermally shrink independently in the longitudinal direction of said pedestal, and an extension line of an axis of said optical fiber joining said connection points passes through a contact surface (K) of said pedestal and a connection part of said base plate, wherein a dimension of said connection part of said base plate is 1.0015 times or more larger than that of a connection concavity in the longitudinal direction of said pedestal.