Thermally compensated fiber bragg grating assembly

Abstract

A thermally compensated Fiber Bragg Grating (FBG) assembly has an FBG mounted on a substrate of a material having a very low coefficient of thermal expansion relative to that for the FBG so that the FBG is constrained to expand/contract at the very low coefficient of thermal expansion. In one form an optical fiber with the FBG somewhere in the middle is wrapped under tension around a spool as the substrate at a maximum operating temperature of the FBG assembly. The opposing ends of the optical fiber are attached to the spool so that the FBG is constrained to expand/contract in accordance with the CTE of the spool. Alternatively the FBG may be securely attached along its length on the substrate at a minimum operating temperature of the FBG assembly to constrain the FBG to expand/contract at the CTE of the substrate.

Dependencies are inferred from the claim text.