Simultaneous measurement of multiparameters using a Sagnac interferometer with polarization maintaining side-hole fiber

Abstract

A Sagnac interferometer with a section of a polarization maintaining side-hole fiber for multiparameter measurement is proposed. The sensor was experimentally demonstrated to be sensitive to torsion, temperature, and longitudinal strain, simultaneously. The birefringence in the investigated side-hole fiber is induced simultaneously by the elliptical shape of a germanium-doped core and by field overlap with the air holes surrounding the core. The latter effect is purely geometrical and causes high chromatic dispersion of the group birefringence in the long wavelength range, which results in a different period of spectral interference fringes. A different wavelength response is obtained for each interference fringe peak when the fiber is subjected to torsion, temperature, or longitudinal strain. A matrix equation for simultaneous measurement of the three parameters--torsion, temperature, and longitudinal strain--is also proposed.

High-Birefringent Fiber Loop Mirror Sensors: New Developments

“…Breakthrough of Hi-Bi FLM configurations 1997 Temperature sensor ; temperature sensing in NIR ; strain sensor (Campbell et al, 1997(Campbell et al, ) 1999 Strain sensor (Campbell et al, 1999) 2004 Temperature PCF sensor (Kim, D. H. & Kang, 2004); temperature insensitivity using PCF (Zhao et al, 2004(Zhao et al, ) 2005 Interrogation system using PCF (Yang et al, 2005); displacement sensor (Liu et al, 2005) 2006 Liquid level sensor (Dong, B. et al, 2006); FBG interrogation system ; LPG/Hi-Bi FLM (Frazao et al, 2006b) 2007 Review of Hi-Bi FLM sensors (Frazao et al, 2007a); strain PCF sensor (Dong, X. Y. et al, 2007;Frazao et al, 2007b) ; chemical etching (Frazao et al, 2007c); concatenated FLM (Frazao et al, 2007d) 2008 Temperature Erbium Hi-Bi fiber (Frazao et al, 2008a); refractive index sensor (Frazao et al, 2008b); multiparameter sensor using side-hole fiber (Frazao et al, 2008c); pressure PCF sensor (Fu et al, 2008); FBG/Hi-Bi FLM (Zhou et al, 2008); current sensor (Marques et al, 2008) 2009 Multiplexing Hi-Bi FLM (Fu et al, 2009); strain and temperature discrimination using two Hi-Bi fibers ); hollow-core PCF sensor (Kim, G. et al, 2009); holey fiber filled with metal indium (Kim, B. H. et al, 2009) 2010 Torsion PCF sensor ; curvature PCF sensor (Gong et al, 2010); pressure-induced SMF ; long distance remote interrogation system (Lee et al, 2010); small core PCF (Andre et al, 2010); intensity strain sensor (Qian et al, 2010); suspended twin-core ; displacement PCF sensor 2011 Hi-Bi FLM with an output port probe ; LPG/Sagnac Loop (Kang et al, 2011); curvature PCF sensor (Hwang et al, 2011); Hi-Bi photonic bandgap Bragg fiber …”

“…A chemical etching was applied to the D-type fiber and presented high sensitivity to refractive index. In the same year, a configuration for simultaneous measurement of multiparameters by using a PM side-hole fiber section in the FLM was proposed (Frazao et al, 2008c). Different parameters were analyzed, like torsion, temperature and longitudinal strain.…”

Photonics Crystal Fiber Loop Mirrors and Their Applications'

“…However, when a HiBi-FLM is used to measure strain or other parameters, its cross-sensitivity to temperature may degrade sensor performance since the optical path length of the HiBi-FLM shows temperature dependence caused by thermal refractive-index change and thermal expansion effect. Thus, the temperature effect must be discriminated or eliminated when they are used for sensing [13][14][15]. The photonic crystal fiber (PCF) is a new class of optical fiber that emerged in recent years.…”

Temperature-independent torsion sensor based on “figure-of-eight” fiber loop mirror

“…In 2008, a Sagnac interferometer with a section of a polarization maintaining side-hole fiber for multiparameter measurement was reported [13]. The sensor was experimentally demonstrated to be sensitive to torsion, temperature, and longitudinal strain, simultaneously.…”