Hydrostatic Pressure Sensing with High Birefringence Photonic Crystal Fibers

The effect of hydrostatic pressure on the waveguiding properties of high birefringence photonic crystal fibers (HiBi PCF) is evaluated both numerically and experimentally. A fiber design presenting form birefringence induced by two enlarged holes in the innermost ring defining the fiber core is investigated. Numerical results show that modal sensitivity to the applied pressure depends on the diameters of the holes, and can be tailored by independently varying the sizes of the large or small holes. Numerical and experimental results are compared showing excellent agreement. A hydrostatic pressure sensor is proposed and demonstrated using an in-fiber modal interferometer where the two orthogonally polarized modes of a HiBi PCF generate fringes over the optical spectrum of a broad band source. From the analysis of experimental results, it is concluded that, in principle, an operating limit of 92 MPa in pressure could be achieved with 0.0003% of full scale resolution

Hybrid Photonic Crystal Fiber Sensing Of High Hydrostatic Pressure

The opto-mechanical response of Hybrid Photonic Crystal Fiber (HPCF) with Ge-doped inclusions is numerically modeled for high hydrostatic pressure sensing purpose. A typical photonic crystal fiber (PCF) consists of a silica solidcore and a cladding with a hexagonal lattice of air-holes. The HPCF is similar to the regular PCF, but a horizontal line of air-holes is substituted by solid high index rods of Ge-doped silica. The optical guidance in HPCFs is supported combining two physical effects: the modified total internal reflection and the photonic bandgap. In such fibers, the Gedoped inclusions induce residual birefringence. In our analysis, we evaluate the susceptibility of the phase modal birefringence and group birefringence to hydrostatic pressure. The analyses were performed at a photonic bandgap with central wavelength near to 1350 nm. The polarimetric pressure sensitivity is about 10 rad/MPa x m at λ = 1175 nm. © 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).7753Oz Optics,Simbol Test Systems, Inc.,FISO Technologies, Inc.,CMC Microsystems Corporation,Innovative Economy: National Strategic Reference FrameworkCerqueira, A.S., Hybrid photonic crystal fiber (2006) Opt. Express, 14 (2), pp. 926-931Cerqueira, A.S., Recent progress and novel applications of photonic crystal fibers (2010) Rep. Prog. Phys., 73, p. 023301Cerqueira, A.S., Birefringence properties of hybrid photonic crystal fibers (2009) Proceedings of Microwave and Optoelectronics Conference (IMOC 2009), pp. 804-806. , Belem, Brazil, 03-06, NovemberFranco, M.A.R., Thermal tunability of photonic bandgaps in photonic crystal fibers selectively filled with nematic liquid crystal Proceedings of 2nd Workshop on Specialty Optical Fibers and Their Applications (WSOF-2), Oaxaca, Mexico, 13-15, October, (2010)Fleming, J.W., Dispersion in GeO2 -SiO2 glasses (1984) Appl. Opt., 23 (24), pp. 4486-4493Martynkien, T., Highly birefringent microstructured fibers with enhanced sensitivity to hydrostatic pressure (2010) Opt. Express, 18 (14), pp. 15113-15121Kühn, B., Schadrack, R., Thermal expansion of synthetic fused silica as a function of OH content and fictive temperature (2009) J. Non-Cryst. Solids, 355, pp. 323-326Gupta, D., Kumar, A., Thyagarajan, K., Polarization mode dispersion in single mode optical fibers due to core-ellipticity (2006) Opt. Commun., 263, pp. 36-41Koshiba, M., (1992) Optical Waveguide Theory by the Finite Element Method, pp. 133-160. , KTK Scientific Publishers and Kluwer Academic Publishers, TokyoUrbanczyk, W., Martynkien, T., Bock, W.J., Dispersion effects in elliptical-core highly birefringent fibers (2001) Appl. Opt., 40 (12), pp. 1911-1920Olszewski, J., Birefringence analysis in photonic crystal fibers with germanium-doped core (2009) J. Opt. A: Pure Appl. Opt., 11, pp. 1-10Martynkien, T., Urbanczyk, W., Modeling of spectral characteristics of Corning PMF-38 highly birefringent fiber (2002) Optik, 113 (1), pp. 25-30Hlubina, P., Broad spectral range measurements and modelling of birefringence dispersion in two-mode elliptical-core fibres (2010) J. Opt., 12, pp. 1-8Martynkien, T., Birefringence in microstructure fiber with elliptical GeO2 highly doped inclusion in the core (2008) Opt. Lett., 33 (23), pp. 2764-2766Verbandt, Y., Polarimetric Optical Fiber Sensors: Aspects of Sensitivity and Practical Implementation (1997) Opt. Rev., 4 (1 A), pp. 75-79Lagakos, N., Bucaro, J.A., Hughes, R., Acoustic sensitivity predictions of single-mode optical fibers using Brillouin scattering (1980) Appl. Opt., 19 (21), pp. 3668-3670Chiang, K.S., Sceats, Wong, D., Ultraviolet photolytic-induced changes in optical fibers: The thermal expansion coefficient (1993) Opt. Lett., 18 (12), pp. 965-96

Design of a highly-birefringent microstructured photonic crystal fiber for pressure monitoring

We present the design of an air hole microstructured photonic crystal fiber for pressure sensing applications. The air-hole photonic crystal lattices were designed to produce a large intrinsic birefringence of 1.16x10-3. The impact of the surrounding air holes for pressure sensing to the propagation mode profiles and indices were studied and improved, which ensures single mode propagation in the fiber core defined by the photonic crystal lattice. An air hole matrix and a practical chemical etching process during the fiber perform preparation stage is proposed to produce an optical fiber with a birefringence-pressure coefficient of 43.89×10-6MPa-1 or a fiber Bragg grating pressure responsivity of 44.15 pm/MPa, which is a 17 times improvement over previous photonic crystal fiber designs. © 2010 Optical Society of America

Fabrication and Sensing Applications of Special Microstructured Optical Fibers

This chapter presents the fabrication of the special microstructured optical fibers (MOFs) and the development of sensing applications based on the fabricated fibers. Particularly, several types of MOFs including birefringent and photosensitive fibers will be introduced. To fabricate the special MOFs, the stack-and-draw technique is employed to introduce asymmetrical stress distribution in the fibers. The microstructure of MOFs includes conventional hexagonal assembles, large-air hole structures, as well as suspended microfibers. The birefringence of MOFs can reach up to 10−2 by designing the air hole structure properly. Fiber Bragg gratings as well as Sagnac interferometers are developed based on the fabricated special MOFs to conduct sensing measurement. Various sensing applications based on MOFs are introduced

PCF Based Sensor with High Sensitivity, High Birefringence and Low Confinement Losses for Liquid Analyte Sensing Applications

In this paper, we report a design of high sensitivity Photonic Crystal Fiber (PCF) sensor with high birefringence and low confinement losses for liquid analyte sensing applications. The proposed PCF structures are designed with supplementary elliptical air holes in the core region vertically-shaped V-PCF and horizontally-shaped H-PCF. The full vectorial Finite Element Method (FEM) simulations performed to examine the sensitivity, the confinement losses, the effective refractive index and the modal birefringence features of the proposed elliptical air hole PCF structures. We show that the proposed PCF structures exhibit high relative sensitivity, high birefringence and low confinement losses simultaneously for various analytes

Magnetic Field Measurements Based on Terfenol Coated Photonic Crystal Fibers

A magnetic field sensor based on the integration of a high birefringence photonic crystal fiber and a composite material made of Terfenol particles and an epoxy resin is proposed. An in-fiber modal interferometer is assembled by evenly exciting both eigenemodes of the HiBi fiber. Changes in the cavity length as well as the effective refractive index are induced by exposing the sensor head to magnetic fields. The magnetic field sensor has a sensitivity of 0.006 (nm/mT) over a range from 0 to 300 mT with a resolution about ±1 mT. A fiber Bragg grating magnetic field sensor is also fabricated and employed to characterize the response of Terfenol composite to the magnetic field

Measurements of polarimetric sensitivity to hydrostatic pressure, strain and temperature in birefringent dual-core microstructured polymer fiber

We experimentally characterized a birefringent microstructured polymer fiber of specific construction, which allows for single mode propagation in two cores separated by a pair of large holes. The fiber exhibits high birefringence in each of the cores as well as relatively weak coupling between the cores. Spectral dependence of the group and the phase modal birefringence was measured using an interferometric method. We have also measured the sensing characteristics of the fiber such as polarimetric sensitivity to hydrostatic pressure, strain and temperature. Moreover, we have studied the effect of hydrostatic pressure and strain on coupling between the cores

Highly Sensitive Dual-Core Photonic Metal Fiber

In this study, we propose an all-solid cladding dual-core metal fiber (DC-MF) filled with toluene and ethanol for temperature sensing applications. Instead of using air holes in the cladding region, we employ fluorine doped silica glass to form an all-solid cladding. By selectively filling toluene and ethanol into three air holes near the core region, we investigate the temperature sensing characteristics numerically. Simulation results demonstrate that the average sensitivity of the temperature sensing can reach -11.64 and -7.41 nm/C within the temperature ranges of 0 to 70 C and -80 to 0 C, respectively, even with a short DC-MF length of 1.6 mm. The maximum sensitivity in the considered temperature ranges can reach up to -15 and -9 nm/C, respectively. Furthermore, the proposed temperature sensor exhibits insensitivity to hydrostatic pressure

Hydrostatic Pressure Sensing With Surface-core Fibers

In this paper, we report the employment of surface-core fibers for hydrostatic pressure sensing. To our knowledge, this is the first demonstration of the use of these fibers for the referenced purpose. Theoretical simulations of the fiber structure were performed in order to estimate fiber phase and group birefringence values and its pressure sensitivity coefficient. In order to test fiber performance when acting as a pressure sensor, the same was placed in an polarimetric setup and its spectral response was measured. A sensitivity of 4.8 nm/MPa was achieved, showing good resemblance to the expected sensitivity value (4.6 nm/MPa).963

Polarimetric sensitivity to hydrostatic pressure and temperature in birefringent dual-core microstructured polymer fiber

We experimentally characterized a birefringent microstructured polymer fiber of specific construction, which allows for single mode propagation in two cores separated by a pair of large holes. The fiber exhibits high birefringence in each of the cores as well as relatively weak coupling between the cores. Spectral dependence of the group and the phase modal birefringence was measured using an interferometric method. We have also measured the sensing characteristics of the fiber such as the polarimetric sensitivity to hydrostatic pressure and temperature