The intelligent structural health monitoring method, which uses a fiber Bragg grating （FBG） sensor, is a new approach in the field of civil engineering. However, it lacks a reliable FBG-based accelerometer for takin...The intelligent structural health monitoring method, which uses a fiber Bragg grating （FBG） sensor, is a new approach in the field of civil engineering. However, it lacks a reliable FBG-based accelerometer for taking structural low frequency vibration measurements. In this letter, a fiextensional FBG-based accelerometer is proposed and demonstrated. The experimental results indicate that the natural frequency of the developed accelerometer is 16.7 Hz, with a high sensitivity of 410.7 pm/g. In addition, it has a broad and flat response over low frequencies ranging from 1 to 10 Hz. The natural frequency and sensitivity of the accelerometer can be tuned by adding mass to tailor the sensor performance to specific applications. Experimental results are presented to demonstrate the good performance of the proposed FBG-based accelerometer. These results show that the proposed accelerometer is satisfactory for low frequency vibration measurements.展开更多
A compact fiber Bragg grating （FBG） diaphragm accelerometer based on L-shaped rigid cantilever beam is proposed and experimentally demonstrated. The sensing system is based on the integration of a flat diaphragm and...A compact fiber Bragg grating （FBG） diaphragm accelerometer based on L-shaped rigid cantilever beam is proposed and experimentally demonstrated. The sensing system is based on the integration of a flat diaphragm and an L-shaped rigid cantilever beam. The FBG is pre-tensioned and the two side points are fixed, efficiently avoiding the unwanted chirp effect of grating. Dynamic vibration measurement shows that the proposed FBG diaphragm accelerometer provides a wide frequency response range （0-110 Hz） and an extremely high sensitivity （106.5 pm/g）, indentifying it as a good candidate for embedding structural health monitoring and seismic wave measurement.展开更多
A micro Fabry-Perot interferometer （M-FPI） is constructed by splicing a short section of polarization- maintaining photonic crystal fiber （PM-PCF） to an end-cleaved single-mode fiber with controllable offset. Due ...A micro Fabry-Perot interferometer （M-FPI） is constructed by splicing a short section of polarization- maintaining photonic crystal fiber （PM-PCF） to an end-cleaved single-mode fiber with controllable offset. Due to the high effective optical path difference induced by the solid core of the PCF, the M-FPI has an ultrasmall cavity of approximately 110 μm. The temperature sensitivity within a range from 33 ℃ to approximately 600 ℃ is measured to be 13.8 pm/℃, which shows good agreement with the theoretical result. This proposed sensor has the advantages of ultracompact size and high stability. Therefore, it is suitable for various space-limited sensing applications in harsh environments.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 60727004 and 61077060)the National High Technology Research and Development Program of China (Nos. 2007AA03Z413 and 2009AA06Z203)+1 种基金the International S&T Cooperation Project of MOST of China (No. 2008CR1063)the Key Scientific and Technological Research Project of Shaanxi Province,China (Nos. 20092KC01-19 and 2008ZDGC-14)
文摘The intelligent structural health monitoring method, which uses a fiber Bragg grating （FBG） sensor, is a new approach in the field of civil engineering. However, it lacks a reliable FBG-based accelerometer for taking structural low frequency vibration measurements. In this letter, a fiextensional FBG-based accelerometer is proposed and demonstrated. The experimental results indicate that the natural frequency of the developed accelerometer is 16.7 Hz, with a high sensitivity of 410.7 pm/g. In addition, it has a broad and flat response over low frequencies ranging from 1 to 10 Hz. The natural frequency and sensitivity of the accelerometer can be tuned by adding mass to tailor the sensor performance to specific applications. Experimental results are presented to demonstrate the good performance of the proposed FBG-based accelerometer. These results show that the proposed accelerometer is satisfactory for low frequency vibration measurements.
基金supported by the National Natural Science Foundation of China(Nos.60727004 and 61077060)the National "863" Program of China(Nos. 2007AA03Z413 and 2009AA06Z203)+2 种基金the Ministry of Education Project of Science and Technology Innovation (No.Z08119)the Ministry of Science and Technology Project of International Cooperation(No.2008CR1063)the Shaanxi Province Project of Science and Technology Innovation(Nos.2009ZKC01-19 and 2008ZDGC14)
文摘A compact fiber Bragg grating （FBG） diaphragm accelerometer based on L-shaped rigid cantilever beam is proposed and experimentally demonstrated. The sensing system is based on the integration of a flat diaphragm and an L-shaped rigid cantilever beam. The FBG is pre-tensioned and the two side points are fixed, efficiently avoiding the unwanted chirp effect of grating. Dynamic vibration measurement shows that the proposed FBG diaphragm accelerometer provides a wide frequency response range （0-110 Hz） and an extremely high sensitivity （106.5 pm/g）, indentifying it as a good candidate for embedding structural health monitoring and seismic wave measurement.
基金supported by the National Natural Science Foundation of China(Nos.61077006,60727004,and 61077060)the National "863" Program of China(Nos. 2007AA03Z413 and 2009AA06Z203)+3 种基金the Ministry of Education Project of Science and Technology Innovation (No.Z08119)the Ministry of Science and Technology Project of International Cooperation(No.2008CR1063)Shaanxi Province Project of Science and Technology Innovation (Nos.2009ZKC01-19 and 2008ZDGC-14)Northwestern University Teaching and Research Project (Nos.YC07059 and KJG10036)
文摘A micro Fabry-Perot interferometer （M-FPI） is constructed by splicing a short section of polarization- maintaining photonic crystal fiber （PM-PCF） to an end-cleaved single-mode fiber with controllable offset. Due to the high effective optical path difference induced by the solid core of the PCF, the M-FPI has an ultrasmall cavity of approximately 110 μm. The temperature sensitivity within a range from 33 ℃ to approximately 600 ℃ is measured to be 13.8 pm/℃, which shows good agreement with the theoretical result. This proposed sensor has the advantages of ultracompact size and high stability. Therefore, it is suitable for various space-limited sensing applications in harsh environments.
