• Title/Summary/Keyword: Bragg Grating Sensors

Search Result 207, Processing Time 0.021 seconds

Planar Optical Waveguide Temperature Sensor Based on Etched Bragg Gratings Considering Nonlinear Thermo-optic Effect

  • Ahn, Kook-Chan;Lee, Sang-Mae;Jim S. Sirkis
    • Journal of Mechanical Science and Technology
    • /
    • v.15 no.3
    • /
    • pp.309-319
    • /
    • 2001
  • This paper demonstrates the development of optical temperature sensor based on the etched silica-based planar waveguide Bragg grating. Topics include design and fabrication of the etched planar waveguide Bragg grating optical temperature sensor. The typical bandwidth and reflectivity of the surface etched grating has been ∼0.2nm and ∼9%, respectively, at a wavelength of ∼1552nm. The temperature-induced wavelength change is found to be slightly non-linear over ∼200$^{\circ}C$ temperature range. Typically, the temperature-induced fractional Bragg wavelength shift measured in this experiment is 0.0132nm/$^{\circ}C$ with linear curve fit. Theoretical models with nonlinear temperature effect for the grating response based on waveguide and plate deformation theories agree with experiments to within acceptable tolerance.

  • PDF

Development flexible force sensor using fiber bragg grating (광섬유 브래그 격자를 이용한 촉각센서용 유연 단위 힘 센서 개발)

  • Heo, Jin-Seok;Kim, Man-Sub;Lee, Jung-Ju
    • Journal of Sensor Science and Technology
    • /
    • v.15 no.4
    • /
    • pp.251-256
    • /
    • 2006
  • This paper describes the flexible force sensor using fiber Bragg grating (FBG) and silicone rubber for the tactile sensation to detect the distributed normal force. The newly designed FBG flexible force has simple structure and can be easily multiplexed with simple wiring compared with the other electric mechanical sensors. We designed the flexible silicone rubber transducer and found the optimum embedding position of FBG in the transducer using the finite element analysis. This flexible force sensor has good performance and is immunity to the electromagnetic field compared with any other kinds of small force sensors for tactile sensation.

Health monitoring of carbon fiber-reinforced polymer composites in γ-radiation environment using embedded fiber Bragg grating sensors

  • Jing Zhong;Feida Chen;Yuehao Rui;Yong Li;Xiaobin Tang
    • Nuclear Engineering and Technology
    • /
    • v.55 no.8
    • /
    • pp.3039-3045
    • /
    • 2023
  • Fiber-reinforced polymer (FRP) composites are considered suitable candidates for structural materials of spacecrafts due to their excellent properties of high strength, light weight, and corrosion resistance. An online health monitoring method for FRP composites must be applied to space structures. However, the application of existing health monitoring methods to space structures is limited due to the harsh space environment. Here, carbon fiber-reinforced polymer (CFRP) composites embedded with fiber Bragg grating (FBG) sensors were prepared to explore the feasibility of strain monitoring using embedded FBG sensors in γ-radiation environment. The analysis of the influence of radiation on the strain monitoring demonstrated that the embedded FBG can be successfully applied to the health monitoring of FRP composites in radiation environment.

Evanescent Wave-Based Fiber Bragg Grating Biosensors

  • Lee, Sang-Mae;Kim, Deug;Dagenais, Mario;Chryssis, Athanasios N.;Saini, Simarjeet Singh;Yi, Hyunmin;Bentley, William E.
    • Proceedings of the Optical Society of Korea Conference
    • /
    • 2006.07a
    • /
    • pp.399-400
    • /
    • 2006
  • Etched fiber Bragg grating, Sensitivity of fiber-Bragg-grating sensors to index of surrounding, Hybridization of DNA

  • PDF

Development of a Damage Monitoring Technique for Jacket-type Offshore Structures using Fiber Bragg Grating Sensors (광섬유 브래그 격자 센서를 활용한 재킷식 해양구조물의 손상 감지 기법 개발)

  • Park, Hyun-Jun;Koo, Ki-Young;Yi, Jin-Hak;Yun, Chung-Bang
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.31 no.6A
    • /
    • pp.399-408
    • /
    • 2011
  • Development of smart sensors for structural health monitoring and damage detection has been advanced remarkably in recent years. Nowadays fiber optic sensors, especially fiber Bragg grating (FBG) sensors, have attracted many researchers' interests for their attractive features, such as multiplexing capability, durability, lightweight, electromagnetic interference immunity. In this paper, a damage detection approach of jacket-type offshore structures by principal component analysis (PCA) technique using FBG sensors are presented. An experimental study for a tidal current power plant structure as one of the jacket-type offshore structures was conducted to investigate the feasibility of the proposed method for damage monitoring. It has been found that the PCA technique can efficiently eliminate environmental effects from measured data by FBG sensors, resulting more damage-sensitive features under various environmental variations.

Strain Transmission Characteristics of Packaged Fiber Bragg Grating Sensors for Structural Health Monitoring

  • Cho, Sung-In;Yoo, Seung-Jae;Kim, Eun-Ho;Lee, In;Kwon, Il-Bum;Yoon, Dong-Jin
    • Journal of the Korean Society for Nondestructive Testing
    • /
    • v.30 no.3
    • /
    • pp.236-243
    • /
    • 2010
  • Fiber Bragg grating(FBG) sensor arrays can be used to monitor the mechanical behavior of the large composite structures such as wind turbine rotor blades and aircrafts. However, brittle FBG sensors, especially multiplexed FBG sensors are easily damaged when they are installed in the flexible structures. As a protection of brittle FBG sensors, epoxy packaged FBG sensors have been presented in this paper. Finite element analysis and experiments were performed to evaluate the effects of adhesives, packaging materials and the bonding layer thickness on the strain transmission. Two types of epoxy were used for packaging FBG sensors and the sensor probes were attached with various bonding layer thickness. It was observed that thin bonding layer with high elastic modulus ratio of the adhesive to packaging provided good strain transmission. However, the strain transmission was significantly decreased when elastic modulus of the adhesive was much lower than the packaged FBG sensor probe's one.

Spectrum analysis of the FBG sensor signal and location determination of FBG sensor into the $H_2$ pressure vessel (해석적인 기법을 통한 FBG 센서의 스펙트럼 분석 및 수소고압용기의 센서 삽입위치 결정)

  • Park, S.O.;Kim, C.U.;Park, J.S.;Kim, C.G.
    • Proceedings of the Korean Society For Composite Materials Conference
    • /
    • 2005.04a
    • /
    • pp.25-28
    • /
    • 2005
  • The optical fiber is known for the proper sensor which can accomplish the structural health monitoring, Fiber Bragg Grating sensors are being studied more than any other fiber optic sensors due to good multiplexing capabilities. But because the signal stability of FBG sensors can be influenced by the strain gradient, it needs to analyze signal of FBG sensors. Particularly acoording to strain gradient induced by structural geometry or cracks, the spectrum peak of the FBG sensor signal can be split easily. In this paper, the spectrum analysis of the FBG sensor signal was performed and the region of embedment of FBG sensors was determined in $H_2$ pressure vessel by numerical method.

  • PDF

On-line Strain Measurement of Rotating Blade Using Fiber Bragg Grating Sensors and Beam Coupler (광섬유 격자 센서와 빔 커플러를 사용한 회전중인 블레이드의 변형률 측정 방법)

  • Lee, In-Jae;Lee, Jong-Min;Lee, Sang-Bae;Hwang, Yo-Ha
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.16 no.11 s.116
    • /
    • pp.1172-1178
    • /
    • 2006
  • Measurement of blade strain with sensors directly installed on the blade has one critical issue, how to send the sensor signal to the ground. Strain-gauges have been dominantly used to directly measure stress of a blade and either a slip ring or a telemetry system has to be used to send measured signal to the ground. However, both systems have many inherent problems and sometimes very severe limitations to be practically used. In this paper, new on-line strain monitoring method using. FBG(Fiber Bragg Grating) sensors and a beam coupler is introduced. Measurement of rotor stress using FBG sensors is nothing new, but unlike other system which installs all necessary instruments on the rotor and use telemetry system to send data to the ground, this system makes use of light's unique characteristic - light travels through space. In this new approach, single optical fiber with many FBG sensors is installed on the blade and all other necessary instruments can be installed at ground thereby giving tremendous advantages over slip ring or telemetry system. A reference sensor is also introduced to compensate the beam coupler's transmission loss change due to rotation. The suggested system's good performance is demonstrated with experiments.

High Total Dose Radiation Effects on Fiber Bragg Grating Sensors (광섬유 브래그 격자 센서의 고선량 방사선 효과)

  • Kim, Jong-Yeol;Lee, Nam-Ho;Jung, Hyun-Kyu;Kim, Youngwoong;Han, Won-Taek
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.17 no.6
    • /
    • pp.1425-1431
    • /
    • 2013
  • We have measured the radiation-induced Bragg wavelength shift (BWS) of fiber Bragg grating (FBG) which was inscribed in Ge-doped core silica using a phase mask during irradiation up to a dose of 23 kGy and annealing effects after the gamma-exposure. For packaged FBG sensors, we observed the maximum radiation-induced BWS of about 91 pm during irradiation. Packaged FBG sensors also show higher radiation sensitivity above nearly a factor of two than non-packaged type sensor in the same condition.

Study on the Fiber Bragg Grating Smart Sensors for Containment Structure in Nuclear Power Plant (스마트 구조물용 광섬유 격자센서의 원전격납건물 적용 실험 연구)

  • Kim Ki-Soo;Song Young-Chul;Pang Gi-Sung;Yoon Duk-Joong
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2004.05a
    • /
    • pp.412-415
    • /
    • 2004
  • This study was performed to verify the behaviors of fiber Bragg grating (FBG) sensors attached to the containment structure in the nuclear power plant as a part of structural integrity test which demonstrates that the structural response of the non-prototype primary containment structure is within predicted limits plus tolerances when pressurized to $115\%$ of containment design pressure, and that the containment does not sustain any structural damage.

  • PDF