A simple quasi-distributed fiber sensing interrogation system based on random speckles is proposed for weak fiber Bragg gratings(WFBGs) in this work. Without using tunable lasers or spectrometers, a piece of multimode...A simple quasi-distributed fiber sensing interrogation system based on random speckles is proposed for weak fiber Bragg gratings(WFBGs) in this work. Without using tunable lasers or spectrometers, a piece of multimode fiber is applied to interrogate the WFBGs relying on the wavelength sensitivity of speckles. Instead of the CCD sensor, an InGaAs quadrant detector serves as the receiver to capture the fast-changing speckle patterns. A supervised deep learning algorithm of the multilayer perceptron architecture is implemented to process speckle data and to interrogate temperature changes or dynamic strains. The proposed demodulation system is experimentally demonstrated for WFBGs with 0.1% reflectivity.The experimental results demonstrate that the new system is capable of measuring temperature change with an accuracy of 1℃ and achieving dynamic frequency of 100 Hz. This speckle-based interrogation system paves a new way for distributed WFBGs sensing with a simple design.展开更多
In this paper,a weak fiber Bragg grating(WFBG)based sensing system applied to the cryogenic static test of launch vehicle oxygen tanks has been developed and the results of an evaluation are reported.A customized sens...In this paper,a weak fiber Bragg grating(WFBG)based sensing system applied to the cryogenic static test of launch vehicle oxygen tanks has been developed and the results of an evaluation are reported.A customized sensor encapsulation and installation method allow for precise strain measurement at cryogenic temperatures.The reflection peaks of series-connected WFBGs with low optical loss are obtained,ensuring high system reliability in harsh environments.The experimental results show that the maximum full-scale error is less than 0.81%full-scale error.The temperature is as low as−193℃ during the test.This study also demonstrates a practical method in which WFBG can be used to obtain critical parameters for structural monitoring in a cryogenic environment.展开更多
基金supported by the National Key Research and Development Program of China(No.2021YFC3340400)Key Laboratory of Medical Electronics and Digital Health of Zhejiang Province(No.MEDH202209)+1 种基金Natural Science Foundation of Zhejiang Province(No.LY22F050004)Zhejiang Xinmiao Talents Program(No.2022R409043).
文摘A simple quasi-distributed fiber sensing interrogation system based on random speckles is proposed for weak fiber Bragg gratings(WFBGs) in this work. Without using tunable lasers or spectrometers, a piece of multimode fiber is applied to interrogate the WFBGs relying on the wavelength sensitivity of speckles. Instead of the CCD sensor, an InGaAs quadrant detector serves as the receiver to capture the fast-changing speckle patterns. A supervised deep learning algorithm of the multilayer perceptron architecture is implemented to process speckle data and to interrogate temperature changes or dynamic strains. The proposed demodulation system is experimentally demonstrated for WFBGs with 0.1% reflectivity.The experimental results demonstrate that the new system is capable of measuring temperature change with an accuracy of 1℃ and achieving dynamic frequency of 100 Hz. This speckle-based interrogation system paves a new way for distributed WFBGs sensing with a simple design.
文摘In this paper,a weak fiber Bragg grating(WFBG)based sensing system applied to the cryogenic static test of launch vehicle oxygen tanks has been developed and the results of an evaluation are reported.A customized sensor encapsulation and installation method allow for precise strain measurement at cryogenic temperatures.The reflection peaks of series-connected WFBGs with low optical loss are obtained,ensuring high system reliability in harsh environments.The experimental results show that the maximum full-scale error is less than 0.81%full-scale error.The temperature is as low as−193℃ during the test.This study also demonstrates a practical method in which WFBG can be used to obtain critical parameters for structural monitoring in a cryogenic environment.
