Design and fabrication of a heterostructured cladding solid-core photonic bandgap fiber for construction of Mach-Zehnder interferometer and high sensitive curvature sensor

Abstract

A heterostructured cladding solid-core photonic bandgap fiber (HCSC-PBGF) is designed and fabricated which supports strong core mode and cladding mode transmission in a wide bandgap. An in-line Mach-Zehnder interferometer (MZI) curvature sensor is constructed by splicing single mode fibers at both ends of a HCSC-PBGF. Theoretical analysis of this heterostructured cladding design has been implemented, and the simulation results are consistent with experiment results. Benefiting from the heterostructured cladding design, an enhanced curvature sensing sensitivity of 24.3 nm/m in the range of 0-1.75 m and a high quality interference spectrum with 20 dB fringe visibility are achieved. In order to eliminate the interference of longitudinal strain and transverse torsion on the result of the curvature sensing experiment, we measure the longitudinal strain and transverse torsion sensing properties of HCSC-PBGF, and the results show that the impact is negligible. It is obvious that this high-sensitivity and cost-effective all fiber sensor with a compact structure will have a promising application in fiber sensing.

Temperature-Insensitive Refractive Index Sensor with Etched Microstructure Fiber

“…It is still difficult for a conventional PBG-PCF to achieve the co-existence of a vibrant core and cladding modes. Changing the arrangement of high refractive index rods can increase the confinement loss of the core mode with no obvious change in the band-gap position [18]. So, a microstructurally designed fiber is proposed to increase the confinement loss of the core mode to make sure that the energy can be effectively transferred to the cladding.…”

“…The proposed MOF is fabricated in our laboratory [18]. The Ge-doped and pure silica rods are prepared with the diameter of 1 mm.…”

“…A series of uniform interference fringes with a high extinction ratio (>20 dB) are observed. The insertion loss of splicing an MOF into SMF is mainly due to the mode field mismatch [18]. The transmission intensity of MZI ( I ) can be described as following [19]: I=Icore+Icladding+2IcoreIcladdingcosfalse(ϕfalse) ϕ=2πfalse(neffcore−neffcladdingfalse)Lλ where the I core and I cladding are the intensities of the core and cladding modes; neffcore and neffcladding are the effective refractive indexes of the core and cladding modes, and Φ is the phase difference of the core and cladding modes.…”

Spectrally U-shaped profile of beam propagation factor in all-solid photonic bandgap fiber

“…Large-mode-area (LMA) fibers working with advanced mechanisms have been established as promising candidates for next-generation high-power fiber lasers, benefitting from their potentials in mode area scaling, higher nonlinear threshold, and feasibilities for some functional applications [1][2][3][4][5][6] . More recently, a kind of bandgap-guided microstructure fiber, called the allsolid photonic bandgap fiber (AS-PBGF), has become an emerging research focus [7][8][9][10][11][12] . Free of air-holes structures, AS-PBGF exhibits excellent practical convenience for the high-power platform [13] and portability for the double-cladding design or polarization-maintaining scheme [11] .…”

Hollow Core Bragg Fiber-Based Sensor for Simultaneous Measurement of Curvature and Temperature

“…Dong et al (2018) proposed a curvature fiber sensor based on the cascaded interferometers and the curvature sensitivity reached 4.362 nm/m −1 within 0-1.134 m −1 [6]. Hu et al (2018) reported a heterostructure cladding solid-core photonic bandgap fiber with a curvature sensing sensitivity of 24.3 nm/m −1 in the range of 0-1.75 m −1 [7]. Arrizabalaga et al (2020) used a multi-core fiber to achieve a sensitivity of 17.5 nm/m −1 as a curvature sensor [8].…”