U-Shape Panda Polarization-Maintaining Microfiber Sensor Coated With Graphene Oxide for Relative Humidity Measurement

Abstract

A new U-shape panda polarization-maintaining fiber (PPMF) based microfiber interferometer coated with graphene oxide (GO) film was proposed and experimentally demonstrated for relative humidity (RH) sensing. Experimental results show that the U-shape sensor has refractive index (RI) sensitivity of 1692.5 nm/RIU in the RI range of 1.33 when the diameter of the taper waist is 10.08 µm. The surface of the U-shape sensor was then modified chemically and coated with a thin layer of GO film (59.64 nm) for RH detection and the sensitivity is proportional to RH: as RH increases from 30% to 98%, the sensitivity increases from 0.111 to 0.361 nm/%RH and the response time is 0.28 s. In addition, the cross sensitivity to temperature, stability, reproducibility, and response/recovery time of the RH sensor were studied in detail. The proposed U-shape fiber RH sensor has advantage of high sensitivity, good reproducibility and fast response (0.28 s), which has potential application in areas requiring dynamic measurement of RH variations such as industrial product fabrication process control and breath state monitoring.

A Small Highly Sensitive Glucose Sensor Based on a Glucose Oxidase-Modified U-Shaped Microfiber

“…The following year, the group built a humidity sensor with an asymmetric U-shaped microfiber coupler that featured an ultra-wide detection range (18%RH–95%RH) [ 28 ]. In 2021, Liu et al designed a humidity sensor using graphene oxide (GO)-coated U-shaped microfiber with a sensitivity of up to 0.361 nm/%RH [ 29 ]. As can be seen from the previous works, a U-shaped microfiber sensor not only has high sensitivity but also has a wide detection range.…”

A Sensor With Coating Pt/WO Powder With an Erbium-Doped Fiber Amplifier to Detect the Hydrogen Concentration

“…By contrast, interference-based HSs have gained more research attention because they are simple to fabricate and perform better. Interferometric fiber sensors can be divided into three categories of Mach-Zehnder interferometric (MZI) [19][20][21][22][23][24][25], Fabry-Perot (F-P) interferometer [26], and Sagnac interferometer [27,28]. The principle of optical fibre hydrogen sensor is based on coating a thin layer of hydrogen sensitive material onto the surface of the fibre sensor.…”

Compact fiber Fabry–Perot sensors filled with PNIPAM hydrogel for highly sensitive relative humidity measurement

“…In the swelling effect, the dimension of the hydrophilous material will swell with the change of RH. In general, hydrophilic materials are coated on some particular sensor structures such as U-shaped panda polarization-preserving microfibers [6] , Fabry-Perot interferometers [7] , fiber Bragg gratings [8] , single-mode multimode single-mode [9][10] and a mismatched fused Mach-Zehnder interferometer [11] to convert changes in ambient RH into deformations in the sensor structure. For example, FPI was formed as sensing systems by filling the pores of special microstructured optical fibers (MOFs) with chitosan as a sensing material [12] .…”