Nanostrain measurement using chirped Bragg grating Fabry-Perot interferometer

Abstract

A simple nanostrain direct current (DC) measurement system based on a chirped Bragg grating Fabry-Perot (FP) structure is presented. The FP cavity, formed between the chirped fiber Bragg grating (CFBG) and the fiber end face, presents an aperiodic behavior due to the CFBG. A laser located in the fringe pattern slope is used to interrogate the sensing head. The optical power parameter is analyzed when strain is applied, for long and short period fringe pattern wavelengths, and sensitivities of −2.87 μW/μɛ and −5.48 μW/μɛ are respectively obtained. This configuration presents a resolution of 70 nɛ.

Keywords

Optical fiber sensor / Fabry-Perot interferometer / chirped fiber Bragg grating

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