Interaction Model for a Hi-Bi Fiber Optic Ultrasonic Sensor and the Host Material

Abstract

A dynamic model of an optical fiber segment with polymer coating, which is embedded in concrete, is proposed for evaluating the response of the ultrasonic stress wave in the host material (matrix). The photo-elastic response in the optical fiber and the associated birefringence-induced phase changes are analyzed. The relationship between fiber optic sensor phase change and the ultrasonic wave behavior in the matrix is established.

Investigation of Group Birefringence of Polarisation Maintaining Highly Birefringent Optical Fiber

“…Highly birefringent (Hi-Bi) optical fibers and Hi-Bi microstructured, or Hi-Bi photonic crystal fibers are special optical fibers realized by introducing certain elements with special geometry and appropriate mechanical and optical properties ensuring the creation of a permanent and welldefined birefringence [1]. These kinds of fibers can be used as active parts of an optical fiber sensor of any physical quantity which significantly influences the fiber's birefringence [2][3][4][5][6][7]. In order to interpret the impact of the environment on the fiber's birefringence correctly, one has to know the dispersion of the birefringence of the fiber within the used spectral range, first.…”

Determination of group and phase birefringence dispersion of Hi-Bi optical fiber using a broadband light source

“…The measurable impact of the external physical quantities such as temperature, atmospheric pressure, ultrasound, magnetic field, electric current, force, etc. on the fiber's birefringence can be used for their sensing [1][2][3][4][5][6][7][8] . Recently, also various birefringent photonic crystal fibers (PCF) have emerged, and possible sensing applications have been discussed stemming from their unique mechanical and optical properties [9][10][11][12][13] .…”