Apodisation technology is introduced to optimize fiber Bragg grating based on the analysis of reflectivity spectrum and group delay response of fiber Bragg gratings. The characteristics of Hamming, Gauss and super-Gau...Apodisation technology is introduced to optimize fiber Bragg grating based on the analysis of reflectivity spectrum and group delay response of fiber Bragg gratings. The characteristics of Hamming, Gauss and super-Gauss functions are discussed and the optimization effects of the three apodisation functions on ripple smoothness of reflectivity spectrum,group delay and linear degree are compared respectively. As a result,the optimization effects of Hamming function is better than other two functions. When the bandwidth is less than ldB,Super-Gauss function is the best choice and proper parameters （G and m） of super-Gauss function can be selected expediently for wider bandwidth and better ripple smoothness of reflectivitv soectrum.展开更多
Based on uniform fiber Bragg grating bonded with a magnetostrictive rod in the non-uniform magnetic field,a novel PMD compensation technique is proposed.This all-fiber PMD compensation technology is cost-effective and...Based on uniform fiber Bragg grating bonded with a magnetostrictive rod in the non-uniform magnetic field,a novel PMD compensation technique is proposed.This all-fiber PMD compensation technology is cost-effective and flexible in designing the differential group delay profile.展开更多
Slowing down velocity and controlling time delay of optical pulses in fiber have many potential applications in optical com-munication systems,and a number of theoretical and experimental studies have been done.In thi...Slowing down velocity and controlling time delay of optical pulses in fiber have many potential applications in optical com-munication systems,and a number of theoretical and experimental studies have been done.In this paper,the transmission spectrum and reflective spectrum of active fiber Bragg grating(FBG)couplers are studied,and the analytic expressions of dispersion and time delay are obtained.By changing the detuning and gain coefficient,different dispersions and time delays in active fiber Bragg grating coupler are obtained.The results show that different detunings and gain coefficients can result in various time delays,and thus tunable time delay could be achieved by changing signal frequency or gain coefficient.展开更多
An interrogation system based on two semiconductor optical amplifiers for weak fiber Bragg gratings （FBGs） was proposed. The first semiconductor optical amplifier （SOA） was used to modulate the light, and the seco...An interrogation system based on two semiconductor optical amplifiers for weak fiber Bragg gratings （FBGs） was proposed. The first semiconductor optical amplifier （SOA） was used to modulate the light, and the second SOA separated the reflected signal from the different FBGs through delayed switching. The proposed system has lower insertion loss and higher spatial resolution, and can interrogate the time- and wavelength-division multiplexed FBG array. Up to 50 FBGs, with a reflectivity of 0.2% and a spatial resolution of 5 m along the optical fiber, were distinguished to demonstrate the interrogation system.展开更多
文摘Apodisation technology is introduced to optimize fiber Bragg grating based on the analysis of reflectivity spectrum and group delay response of fiber Bragg gratings. The characteristics of Hamming, Gauss and super-Gauss functions are discussed and the optimization effects of the three apodisation functions on ripple smoothness of reflectivity spectrum,group delay and linear degree are compared respectively. As a result,the optimization effects of Hamming function is better than other two functions. When the bandwidth is less than ldB,Super-Gauss function is the best choice and proper parameters （G and m） of super-Gauss function can be selected expediently for wider bandwidth and better ripple smoothness of reflectivitv soectrum.
文摘Based on uniform fiber Bragg grating bonded with a magnetostrictive rod in the non-uniform magnetic field,a novel PMD compensation technique is proposed.This all-fiber PMD compensation technology is cost-effective and flexible in designing the differential group delay profile.
基金supported by the National Natural Science Foundation of China(No.10704043)the Natural Science Foundation of Zhejiang Province(No.Y1110078)
文摘Slowing down velocity and controlling time delay of optical pulses in fiber have many potential applications in optical com-munication systems,and a number of theoretical and experimental studies have been done.In this paper,the transmission spectrum and reflective spectrum of active fiber Bragg grating(FBG)couplers are studied,and the analytic expressions of dispersion and time delay are obtained.By changing the detuning and gain coefficient,different dispersions and time delays in active fiber Bragg grating coupler are obtained.The results show that different detunings and gain coefficients can result in various time delays,and thus tunable time delay could be achieved by changing signal frequency or gain coefficient.
基金This work was supported in part by the National Science Foundation of China, NSFC （Gram No. 61205070）, and the Major Program of the National Natural Science Foundation of China, NSFC （Grant No. 61290311）.
文摘An interrogation system based on two semiconductor optical amplifiers for weak fiber Bragg gratings （FBGs） was proposed. The first semiconductor optical amplifier （SOA） was used to modulate the light, and the second SOA separated the reflected signal from the different FBGs through delayed switching. The proposed system has lower insertion loss and higher spatial resolution, and can interrogate the time- and wavelength-division multiplexed FBG array. Up to 50 FBGs, with a reflectivity of 0.2% and a spatial resolution of 5 m along the optical fiber, were distinguished to demonstrate the interrogation system.
