scholarly journals Sensitivity-Tunable Oscillator-Accelerometer Based on Optical Fiber Bragg Grating

Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 223
Author(s):  
Xiangpeng Xiao ◽  
Jinpeng Tao ◽  
Qingguo Song ◽  
Yuezhen Sun ◽  
Jiang Yang ◽  
...  

We demonstrate a fiber Bragg grating (FBG)-based oscillator-accelerometer in which the acceleration sensitivity can be tuned by controlling the location of the mass oscillator. We theoretically and experimentally investigated the performance of the proposed accelerometer. Theoretical analysis showed that both the mass and location of the oscillator affect the sensitivity and resonant frequency of the accelerometer. To simplify the analysis, a nondimensional parameter, P, was introduced to tune the sensitivity of the FBG-based oscillator-accelerometer, which is related to the location of the mass oscillator. Numerical analysis showed that the accelerometer sensitivity is linearly proportional to the P parameter. In the experiment, six FBG-based oscillator-accelerometers with different P parameters (0.125, 0.25, 0.375, 0.5, 0.625, 0.75) were fabricated and tested. The experimental results agree very well with the numerical analysis, in which the sensitivity of the proposed accelerometer linearly increased with the increase in parameter P (7.6 pm/g, 15.8 pm/g, 19.3 pm/g, 25.4 pm/g, 30.6 pm/g, 35.7 pm/g). The resonance frequency is quadratically proportional to parameter P, and the resonance frequency reaches the minimum of 440 Hz when P is equal to 0.5. The proposed oscillator-accelerometer showed very good orthogonal vibration isolation.

2019 ◽  
Vol 9 (13) ◽  
pp. 2707
Author(s):  
Kuo Li ◽  
Guoyong Liu ◽  
Yuqing Li ◽  
Jun Yang ◽  
Wenlong Ma

Reducing the size of an accelerometer overcomes the tradeoff between its sensitivity and resonant frequency, and the theoretical relationships are analyzed. A fiber Bragg grating (FBG) accelerometer with the shortest vibration arm, 7 mm, among FBG accelerometers using the optical fiber to hold its inertial object is demonstrated here. The inertial object was 4.41 g. The experimental crest-to-trough sensitivity and resonant frequency, 244 pm/g and 90 Hz, disagree with the theoretical values, 633 pm/g and 67 Hz, perhaps due to the friction between the inertial object and shell. In order to find the theoretical values, a method to find the pre-stretch of the FBG is also presented here, based on the stretch of the FBG at equilibrium and the mass of the inertial object. The FFT program, experimental data and theoretical calculations are presented in detail in the Supplementary Material.


2020 ◽  
Vol 12 (1) ◽  
pp. 4
Author(s):  
Yuqing Li ◽  
Kuo Li ◽  
Guoyong Liu ◽  
Juan Tian ◽  
Yanchun Wang

Fiber Bragg grating (FBG) accelerometers using transverse forces have higher sensitivity but lower resonant frequency than ones using axial forces. By shortening the distance between the two fixed ends of the FBG, the resonant frequency can be improved without lowing the sensitivity. Here, a compact FBG accelerometer using transverse forces with a slightly pre-relaxed FBG and 25mm distance between the two fixed ends has been demonstrated with the crest-to-trough sensitivity 1.1nm/g at 5Hz and the resonant frequency 42Hz. It reveals that making the FBG slightly pre-relaxed rather than pre-stretched also improves the tradeoff between the sensitivity and resonant frequency. Full Text: PDF References:Kawasaki, B. S. , Hill, K. O , Johnson, D. C. , & Fujii, Y. , "Narrow-band Bragg reflectors in optical fibers", Optics Letters 3, 66 (1978) [CrossRef]K. O. Hill, and G. Meltz, "Fiber Bragg grating technology fundamentals and overview", Journal of Lightwave Technology 15, 1263 (1997) [CrossRef]B. Lee, "Review of the present status of optical fiber sensors", Optical Fiber Technology, 9, 57-79 (2003) [CrossRef]Laudati, A. , Mennella, F. , Giordano, M. , D"Altrui, G. , Tassini, C. C. , & Cusano, A., "A Fiber-Optic Bragg Grating Seismic Sensor", IEEE Photonics Technology Letters, 19, 1991 (2007) [CrossRef]P. F. Costa Antunes, C. A. Marques, H. Varum, and P. S. Andre, "Biaxial Optical Accelerometer and High-Angle Inclinometer With Temperature and Cross-Axis Insensitivity", IEEE Sens. J. 12, 2399 (2012) [CrossRef]Guo, Y. , Zhang, D. , Zhou, Z. , Xiong, L. , & Deng, X., "Welding-packaged accelerometer based on metal-coated FBG", Chinese Optics Letters, 11, 21 (2013). [CrossRef]Zhang, Y. , Zhang, W. , Zhang, Y. , Chen, L. , Yan, T. , & Wang, S. , et al., "2-D Medium–High Frequency Fiber Bragg Gratings Accelerometer", IEEE Sensors Journal, 17, 614(2017) [CrossRef]Xiu-bin Zhu, "A novel FBG velocimeter with wind speed and temperature synchronous measurement", Optoelectronics Letters, 14, 276-279 (2018) [CrossRef]Li, K. , Yau, M. H. , Chan, T. H. T. , Thambiratnam, D., "Fiber Bragg grating strain modulation based on nonlinear string transverse-force amplifier", & Tam, H. Y. , Optics Letters, 38, 311 (2013) [CrossRef]Li, K. , Chan, T. H. T. , Yau, M. H. , Nguyen, T. , Thambiratnam, D. P. , & Tam, H. Y., "Very sensitive fiber Bragg grating accelerometer using transverse forces with an easy over-range protection and low cross axial sensitivity", Applied Optics, 52, 6401 (2013) [CrossRef]Li, K. , Chan, T. H. T. , Yau, M. H. , Thambiratnam, D. P. , & Tam, H. Y., "Biaxial Fiber Bragg Grating Accelerometer Using Axial and Transverse Forces", IEEE Photonics Technology Letters, 26, 1549 (2014). [CrossRef]Li, K. , Chan, T. H. , Yau, M. H. , Thambiratnam, D. P. , & Tam, H. Y., "Experimental verification of the modified spring-mass theory of fiber Bragg grating accelerometers using transverse forces", Applied Optics, 53, 1200-1211(2014) [CrossRef]


2021 ◽  
Vol 32 ◽  
Author(s):  
Binh Pham Thanh ◽  
Thuy Van Nguyen ◽  
Van Hoi Pham ◽  
Huy Bui ◽  
Thi Hong Cam Hoang ◽  
...  

In this paper, we report a new type of refractometer based on a D-shaped fiber Bragg grating (FBG) integrated in a loop-mirror optical fiber laser. This proposed sensor is used in wavelength interrogation method, in which the D-shaped FBG is applied as a refractive index (RI) sensing probe and a mirror to select mode of laser. The D-shaped FBG is prepared by the removal of a portion of the fiber cladding covering the FBG by means of side-polishing technique. The D-shaped FBG sensing probe integrated in a loop-mirror optical fiber laser with saturated pump technique, the characteristics of sensing signals have been improved to obtain stable intensity, narrower bandwidth and higher optical signal-to-noise ratio compare to normal reflection configuration. The limit of detection (LOD) of this sensor can be achieved to 2.95 x 10-4 RIU in the refractive index (RI) range of 1.42-1.44. Accordingly, we believe that the proposed refractometer has a huge potential for applications in biochemical-sensing technique.


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