Wavelength-spacing-tunable multichannel filter incorporating a sampled chirped fiber Bragg grating based on a symmetrical chirp-tuning technique without center wavelength shift

2006 ◽  
Vol 31 (24) ◽  
pp. 3571 ◽  
Author(s):  
Young-Geun Han ◽  
Xinyong Dong ◽  
Ju Han Lee ◽  
Sang Bae Lee
Keyword(s):  
Fiber Bragg Grating ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Center Wavelength ◽  
Wavelength Spacing ◽  
Multichannel Filter ◽  
Chirped Fiber Bragg Grating

Smart Structural Health Monitoring Based on Detecting Picometer-Scale Wavelength Shift of Fiber Bragg Grating

2013 ◽  
Vol 562-565 ◽  
pp. 1346-1352
Author(s):  
Jun Jie Bai ◽  
Jian Xing Li ◽  
Jun Zhang ◽  
Xiao Yun Zhang ◽  
Le Wang ◽  
...  
Keyword(s):  
Fiber Bragg Grating ◽  
Sensor Network ◽  
Health Monitoring ◽  
High Speed ◽  
Smart Structure ◽  
Comb Filter ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Center Wavelength ◽  
Fbg Sensor

The real-time monitoring technologies of smart civil structure based on detecting picometer-scale wavelength shift of fiber Bragg grating (FBG), including the wavelength demodulation technology of FBG, are researched extensively at home and abroad. In the paper, using the technologies of wavelength division multiplex (WDM) and time division multiplex (TDM), fiber Bragg grating (FBG) sensor network was built for monitoring smart structure health condition. Based on SOPC (System on Programmable Chip) technology and fiber comb filter, a high-speed and high-precision wavelength demodulation scheme of FBG sensor network was proposed. The optical system and hardware circuit for demodulation system were designed specifically. To improve the accuracy of demodulation system of FBG, a constant temperature channel of the demodulation system connected with a fiber comb filter, which offered reference points to calibrate the Bragg grating center wavelength. Based on 32-bit soft-core processor NoisⅡ, the embedded system collected and processed the photoelectric signal voltage transformed to rectangular voltage pulse. The upper computer displayed dynamically the FBG wavelength demodulation process and calibrated the Bragg grating center wavelength. The experiments of FBG wavelength demodulation and health monitoring of smart structural embedded fiber Bragg gratings were done. Experimental results show that, the FBG wavelength demodulation method can be used to demodulate the FBG wavelength with high speed and high precision (± 2 pm), which can be used extensively in large-scale multipoint monitor engineering, and the strains of the smart structure can be measured accurately.

Tunable and switchable optical bandpass filters using a single linearly chirped fiber Bragg grating

2004 ◽  
Vol 239 (4-6) ◽  
pp. 339-344 ◽  
Author(s):  
Songyang Li ◽  
Nam Quoc Ngo ◽  
Swee Chuan Tjin ◽  
Le Nguyen Binh
Keyword(s):  
Fiber Bragg Grating ◽  
Bandpass Filters ◽  
Bragg Grating ◽  
Chirped Fiber Bragg Grating
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