Patent ID: 6144789
Filing Date: 2000-11-07
Classification: G02B

Abstract:
A temperature compensating device for a prestrained fiber grating of an optical fiber, said temperature compensating device extending along a longitudinal axis of the fiber grating and comprising:a first expansion member formed of a material having a first coefficient of thermal expansion and extending parallel to the longitudinal axis of the fiber grating and having a length between first and second ends at least as long as the fiber grating;a second expansion member formed of a material having a second coefficient of thermal expansion and extending parallel to the longitudinal axis of the fiber grating and having a length between first and second ends at least as long as the fiber grating, said second coefficient of thermal expansion being different from said first coefficient of thermal expansion;a first lever having first and second ends and an intermediate portion, said first lever being flexibly connected to a first end of said first expansion member proximate the first end of said first lever and to a first end of said second expansion member proximate the intermediate portion of said first lever and to a first end of the fiber grating proximate the second end of said first lever; anda second lever having first and second ends and an intermediate portion, said second lever being flexibly connected to a second end of said first expansion member proximate the first end of said second lever and to a second end of said second expansion member proximate the intermediate portion of said second lever and to a second end of the fiber grating proximate the second end of said second lever;wherein said expansion members, said levers and said fiber all lie substantially in a single plane;whereby a change in temperature of said device causes said first and second expansion members to expand and contract differentially, thereby pivoting said first and second levers to vary the axial strain in the fiber grating.