Highly-sensitive gas pressure sensor using twin-core fiber based in-line Mach-Zehnder interferometer

Abstract

A Mach-Zehnder interferometer based on a twin-core fiber was proposed and experimentally demonstrated for gas pressure measurements. The in-line Mach-Zehnder interferometer was fabricated by splicing a short section of twin-core fiber between two single mode fibers. A micro-channel was created to form an interferometer arm by use of a femtosecond laser to drill through one core of the twin-core fiber. The other core of the fiber was remained as the reference arm. Such a Mach-Zehnder interferometer exhibited a high gas pressure sensitivity of -9.6 nm/MPa and a low temperature cross-sensitivity of 4.4 KPa/°C. Moreover, ultra-compact device size and all-fiber configuration make it very suitable for highly-sensitive gas pressure sensing in harsh environments.

High-sensitivity gas pressure sensor based on hollow-core photonic bandgap fiber Mach-Zehnder interferometer

“…3(b), where we can observe that the wavelengths of the three dips change linearly with the gas pressure. Through linear fitting, we get the gas pressure sensitivities of 2.32 nm/kPa, 2.33 nm/kPa and 2.39 nm/kPa for these interference dips, respectively, which are two orders of magnitude higher than that of the previously reported MZI based gas pressure sensors [25,26]. To investigate the influence of the relative length, namely the length difference ΔL of two HC-PBFs, on gas pressure sensitivity, two MZI based sensors with L HC-PBF2 = 10 mm, ΔL = 30 μm, and L HC-PBF2 = 10 mm, ΔL = 140 μm are used for testing the pressure response.…”

“…With the advantages of immunity to electromagnetic interference, fast signal acquisition, high sensitivity and compact structure, optical fiber sensors have been extensively investigated for gas pressure sensing. A variety of optical fiber pressure sensors based on various types of fiber components, including long-period fiber gratings (LPFGs) [1][2][3][4][5][6], fiber Bragg gratings (FBGs) [7][8][9][10][11], and fiber interferometers [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] have been proposed in recent years. LPFGs inscribed in single-mode fiber (SMF) [1], photonic crystal fiber [2][3][4], polymer micro-structured fiber [5], boron co-doped optical fiber [6] and FBGs inscribed in single-mode fiber [7,8], side-hole fiber [9], air-hole micro-structured fiber [10,11], have been used as gas pressure sensors, respectively.…”

“…Mach-Zehnder interferometer (MZI) has also been employed as gas pressure sensor. The fiber in-line MZIs based on an inner air-cavity with open micro-channel [25] and twin-core fiber [26] have been demonstrated for gas pressure sensing with the sensitivity of 8.239 pm/kPa and −9.6 pm/kPa, respectively. Overall, the sensitivity of the MZI based gas pressure sensor is relatively low, which needs to be further improved.…”

Analytical Analysis and Experimental Validation of a Multi-parameter Mach-Zehnder Fiber Optic Interferometric Sensor

“…Zehnder, [1], [3], [5]- [7]. It has been widely seen that for each sensor constructed, values such as their sensitivity and operational range is often highly dependent on the sensors length.…”

Numerical Investigation of Simultaneous Refractive index Sensor using 1D multichannel photonic crystal device

“…Sensor is a device which senses the physical, biological and chemical changes in parameters such as refractive index [1][2][3][4], temperature [5], pressure [6], pH [7], gas [8], magnetic uid [9] and so on. Sensors based on optics have a lot of attention in detecting the small changes in temperature, pressure, chemical composition etc., due to their high sensitivity [10].…”