Strain-Insensitive Temperature Sensor Based on Few-Mode Fiber and Photonic Crystal Fiber

Abstract

Based on few-mode fiber (FMF) and photonic crystal fiber (PCF), a new temperature sensor with a FMF-PCF-FMF hybrid construction has been developed. Furthermore, the sensor has a longitudinally symmetrical structure that makes it have a flexible sensor head, which enhances the practical performance. Simulated results show that there are three resonant peaks with extinction ratio above 18 dB in the wavelength from 1630 nm to 1720 nm, and the temperature can be measured by calculating wavelength shift of resonant peaks. The experimental results show that the temperature sensitivity of the proposed sensor is as high as 38.6 pm/°C when the temperature ranges from 20°C to 80°C. Meanwhile, the strain sensitivity of the proposed sensor is as low as −0.457 pm/με when strain ranges from 0 to 3000 με. The high temperature sensitivity and ultralow strain sensitivity indicate that the proposed sensor can effectively eliminate the cross-sensitive issue of temperature and strain. In addition to excellent sensing performances, simple and compact structure make the proposed sensor be potential in practical applications.

Amplitude modulated feed-forward thermal drift compensation for linear and nonlinear current sensors

“…current sensors. Based on the expressions mentioned above, equation ( 5) can be simplified to an expression shown in equation (6),…”

“…Some of the recent literature has demonstrated this issue in atomic force microscopy [2], capacitive displacement probes [3], capacitive flow meters [4], and nuclear reactors [5]. In [6], the paper discusses some photonic crystal fibers and few-mode fibers to design a temperature sensor. The error related to strain drift is eliminated using this special design of the fiber structure and is able to measure temperature effectively.…”

Fiber optic sensor for transformer temperature detection

“…The sensor has a temperature sensitivity of 38.6 pm/°C in the range of 20-80°C. 13 Although this sensor has the advantage of small cross-sensitivity, its temperature detection range is low and its temperature sensitivity is not high. Fan et al 14 proposed an ultrahigh sensitivity temperature sensor based on nematic liquid crystal (NLC) film coated cascaded Sagnac interferometer (CSI), the temperature sensitivity reached 43.13 nm/°C in the 38-40°C.…”

“…Gao et al designed a stress‐insensitive fiber‐optic temperature sensor using few‐mode fiber (FMF) and photonic crystal fiber (PCF), also known as FMF–PCF–FMF. The sensor has a temperature sensitivity of 38.6 pm/°C in the range of 20–80°C 13 . Although this sensor has the advantage of small cross‐sensitivity, its temperature detection range is low and its temperature sensitivity is not high.…”

A spatially non-overlapping dual-wavelength 2D FBG for the measurement of temperature and strain

“…In practical application, it is a pressing problem to eliminate the cross sensitivity between temperature and strain [8][9][10]. The current solutions include reference to fiber gratings [11][12][13], the combination of different gratings [14][15][16][17][18], the fusion of fiber gratings with different cladding diameters [19][20][21], chirped fiber gratings [22], Fabry-Perot (FP)cavities [23][24][25][26], and microstructured fiber gratings [27][28][29][30]. Among these methods, referring to fiber gratings requires that the two gratings must have identical structures and parameters, raising higher requirements for fabricating.…”