Hollow-Core Photonic Crystal Fiber Mach–Zehnder Interferometer for Gas Sensing

Abstract

A novel and compact interferometric refractive index (RI) point sensor is developed using hollow-core photonic crystal fiber (HC-PCF) and experimentally demonstrated for high sensitivity detection and measurement of pure gases. To construct the device, the sensing element fiber (HC-PCF) was placed between two single-mode fibers with airgaps at each side. Great measurement repeatability was shown in the cyclic test for the detection of various gases. The RI sensitivity of 4629 nm/RIU was demonstrated in the RI range of 1.0000347–1.000436 for the sensor with an HC-PCF length of 3.3 mm. The sensitivity of the proposed Mach–Zehnder interferometer (MZI) sensor increases when the length of the sensing element decreases. It is shown that response and recovery times of the proposed sensor inversely change with the length of HC-PCF. Besides, spatial frequency analysis for a wide range of air-gaps revealed information on the number and power distribution of modes. It is shown that the power is mainly carried by two dominant modes in the proposed structure. The proposed sensors have the potential to improve current technology’s ability to detect and quantify pure gases.

Selectivity in trace gas sensing: recent developments, challenges, and future perspectives

“…, PhC waveguide, 211,212 PhC nanoresonator, 213,214 PhC cavity, 215,216 polymeric PhC, 217 1-D PhC, 218,219 2-D PhC, 83,220 3-D PhC, 221 plasmonic PhC, 222 MEMS PhC, 223 porous PhC, 224 and PhC fiber. 164,225,226…”

A Review: Application and Implementation of Optic Fibre Sensors for Gas Detection

“…In this section of the review, we discuss the development of devices that exploit the properties of evanescent electric fields without the use of metallic coatings or gratings that interact with the surrounding environment. There are four principal types, namely, in-fibre Mach-Zehnder (MZ), exposed fibre core, conically tapered fibres, and random-hole fibres [33][34][35][36][37][38]. A number of different methods have been investigated to fabricate fibre MZ interferometers; for example, using a fibre fusion splicer to shape a pair of biconical fibres or to create a fibre with a large lateral off-set, or fusion splicing sections of a PCF.…”

“…Group 2-fibre grating sensors, including long period gratings, Bragg gratings, and tilted Bragg gratings [27][28][29][30][31][32]. Group 3-evanescent field sensors, including in-fiber Mach-Zehnders, exposed fibre cores, conically tapered fibres, and random-hole optical fibers [33][34][35][36][37][38]. Group 4-plasmonic sensors, including surface plasmon resonance, localised surface plasmons, and conjoined surface plasmon [39][40][41][42][43][44].…”

All-Fiber Fabry-Perot Interferometer Gas Refractive Index Sensor Based on Hole-Assisted One-Core Fiber and Vernier Effect

“…O PTICAL fiber sensors have been intensively developed in fields of industry, environment and biological over the last decades owing to many intrinsic advantages of flexibility, remote sensing capability, electrically passive operation and immunity to electromagnetic interference [1]- [3]. Among them, the fiber-optic sensors based on Fabry-Perot interferometer (FPI) have attracted increasing attentions in fiber sensing applications due to compact structure, small cross sensitivity, good stability and resist to external vibration interference [4]- [6].…”