Highly Sensitive Vector Curvature Sensor Based on Two Juxtaposed Fiber Michelson Interferometers With Vernier-Like Effect

In this paper, a highly sensitive vector curvature sensor based on two juxtaposed fiber Michelson interferometers (MI) with Vernier-like effect has been proposed and verified. Different from the structures of the conventional Vernier effect which are composed of the cascaded elements, the proposed configuration consists of two juxtaposed MIs. A triple-core fiber (TCF) is connected with a quite short piece of dual-side-hole fiber (DSHF), and the core of the DSHF and the two eccentric cores of the TCF are respectively constituted two juxtaposed MIs. The Vernier-like effect is caused by the very small refractive index difference between the two eccentric cores of the TCF. The most outstanding feature of the proposed structure is that the two MIs are both sensitive to curvature with opposite sensitivities, which makes the curvature sensitivity magnification factor twice that of the conventional Vernier effect structure. Experimental results show that the curvature sensitivity of the structure can reach $-60.84~{\mathrm {nm/m}}^{-1}$ .

[1]  Libo Yuan,et al.  Two-Axis Bending Sensor Based on Cascaded Eccentric Core Fiber Bragg Gratings , 2016, IEEE Photonics Technology Letters.

[2]  Ian Bennion,et al.  Bend sensors with direction recognition based on long-period gratings written in D-shaped fiber. , 2004, Applied optics.

[3]  Songnian Fu,et al.  Cascaded fiber-optic Fabry-Perot interferometers with Vernier effect for highly sensitive measurement of axial strain and magnetic field. , 2014, Optics express.

[4]  Libo Yuan,et al.  Highly Sensitive Directional Bending Sensor Based on Eccentric Core Fiber Mach–Zehnder Modal Interferometer , 2016, IEEE Sensors Journal.

[5]  Heather Patrick,et al.  Long period fibre gratings for structural bend sensing , 1998 .

[6]  Libo Yuan,et al.  An Integrated Fiber Michelson Interferometer Based on Twin-Core and Side-Hole Fibers for Multiparameter Sensing , 2018, Journal of Lightwave Technology.

[7]  Yunshan Zhang,et al.  Two-dimensional microbend sensor based on long-period fiber gratings in an isosceles triangle arrangement three-core fiber. , 2017, Optics letters.

[8]  J. G. Burnett,et al.  Bend measurement using Bragg gratings in multicore fibre , 2000 .

[9]  Yuan Luo,et al.  Sensitivity-enhanced temperature sensor with cascaded fiber optic Sagnac interferometers based on Vernier-effect , 2015 .

[10]  Li Wang,et al.  A Fiber Bending Vector Sensor Based on M–Z Interferometer Exploiting Two Hump-Shaped Tapers , 2015, IEEE Photonics Technology Letters.

[11]  Vittorio M. N. Passaro,et al.  Recent Advances in Gas and Chemical Detection by Vernier Effect-Based Photonic Sensors , 2014, Sensors.

[12]  H. Fu,et al.  Sensitivity enhanced fiber sensor based on a fiber ring microwave photonic filter with the Vernier effect. , 2017, Optics express.

[13]  Mingran Quan,et al.  Ultra-high sensitivity Fabry-Perot interferometer gas refractive index fiber sensor based on photonic crystal fiber and Vernier effect. , 2015, Optics letters.

[14]  Faramarz Farahi,et al.  Temperature and strain insensitive bending measurements with D-type fibre Bragg gratings , 2001 .

[15]  Anand Asundi,et al.  Structural health monitoring using a fiber optic polarimetric sensor and a fiber optic curvature sensor - static and dynamic test , 2001 .

[16]  Li Wang,et al.  Two-dimensional bending vector sensor based on Mach–Zehnder interferometer of two orthogonal lateral-offsets , 2015 .

[17]  Deming Liu,et al.  Sensitivity amplification of fiber-optic in-line Mach-Zehnder Interferometer sensors with modified Vernier-effect. , 2017, Optics express.

[18]  Shizhuo Yin,et al.  Multiple parameter vector bending and high-temperature sensors based on asymmetric multimode fiber Bragg gratings inscribed by an infrared femtosecond laser. , 2006, Optics letters.

[19]  Li Pei,et al.  Highly sensitive curvature sensor based on asymmetrical twin core fiber and multimode fiber , 2017 .

[20]  Deming Liu,et al.  Simplified Hollow-Core Fiber-Based Fabry–Perot Interferometer With Modified Vernier Effect for Highly Sensitive High-Temperature Measurement , 2015, IEEE Photonics Journal.

[21]  Xu Liu,et al.  Highly Sensitive Airflow Sensor Based on Fabry–Perot Interferometer and Vernier Effect , 2016, Journal of Lightwave Technology.

[22]  Zhihao Chen,et al.  Textile Fiber Optic Microbend Sensor Used for Heartbeat and Respiration Monitoring , 2015, IEEE Sensors Journal.

[23]  Jian Ju,et al.  Directional Bend Sensing With a CO $_{2}$-Laser-Inscribed Long Period Grating in a Photonic Crystal Fiber , 2009, Journal of Lightwave Technology.

[24]  M. Rohn,et al.  Magnetoelastic skin curvature sensor for biomedical applications , 2004, Proceedings of IEEE Sensors, 2004..

[25]  A. Frizera-Neto,et al.  Hysteresis compensation technique applied to polymer optical fiber curvature sensor for lower limb exoskeletons , 2017 .

[26]  Yi-Ping Wang,et al.  A novel long period fiber grating sensor measuring curvature and determining bend-direction simultaneously , 2005, IEEE Sensors Journal.

[27]  Roger Haynes,et al.  Long period grating in multicore optical fiber: an ultra-sensitive vector bending sensor for low curvatures. , 2014, Optics letters.

[28]  Jacques Albert,et al.  Bending sensor combining multicore fiber with a mode-selective photonic lantern. , 2015, Optics letters.