High-birefringence fiber loop mirrors and their applications as sensors

TLDR

The reflection and transmission properties of a high‑birefringence fiber loop mirror (HiBi‑FLM) composed of a standard coupler and one‑ or multi‑section high‑birefringence fibers are analyzed in detail. The study proposes and demonstrates a novel strain–temperature sensor based on HiBi‑FLM characteristics. The authors calculate reflectivity and transmissivity for HiBi‑FLMs with arbitrary section numbers and analyze the one‑section device’s response to strain and temperature both theoretically and experimentally. Theoretical expressions for reflectivity and transmissivity of HiBi‑FLMs with up to three sections were derived and experimentally validated, confirming the model and enabling a new strain–temperature sensor.

Abstract

The reflection and transmission characteristics of a high-birefringence fiber loop mirror (HiBi-FLM), which is composed of a standard fiber coupler and one-section or multisection high-birefringence fibers (HBFs), are analyzed and discussed in detail. Theoretical reflectivity and transmissivity expressions for HiBi-FLMs with one-, two-, and three-section HBFs were obtained. The procedure for calculating reflectivity and transmissivity for HiBi-FLMs with n-section HBFs is given. Experimental results have verified the theoretical model. The basic characteristics of the one-section HiBi-FLM when strain and high temperature are applied to HBFs were analyzed and investigated theoretically and experimentally. The experimental results are in good agreement with the theoretical analysis. Furthermore, a strain– temperature sensor that makes use of those characteristics, which is new for applications of HiBi-FLMs, has been proposed and demonstrated.