Optical fiber interferometric sensors based on [3×3] couplers have been used in many fields. A new technique is proposed to demodulate output signals of this kind of sensors. The technique recovers the signal of ...Optical fiber interferometric sensors based on [3×3] couplers have been used in many fields. A new technique is proposed to demodulate output signals of this kind of sensors. The technique recovers the signal of interest by fitting coefficients of elliptic （Lissajous） curves between each fiber pair. Different from other approaches, this technique eliminates the dependence on the idealization of [3×3] coupler, provides enhanced tolerance to the variance of photoelectric converters, and is anti-polarization in a certain extent. The main algorithm has been successfully demonstrated both by numerical simulation and experimental result.展开更多
In order to increase the multiplexing density of the fiber Bragg gratings （FBGs） for a low cost per-sensor, based on the analysis of the spectrum shadow distortion （SSD）, a novel successive demultiplexing scheme f...In order to increase the multiplexing density of the fiber Bragg gratings （FBGs） for a low cost per-sensor, based on the analysis of the spectrum shadow distortion （SSD）, a novel successive demultiplexing scheme for FBG sensors has been developed. It is based on the optical cade division multiple access （CDMA） balanced demodulation. A high-density multiplexing-demultiplexing system for FBG sensors has been designed, and corresponding simulation carried out has demonstrated that the FBG sensors＇ reflective signals can still be obtained accurately and respectively, even if FBG sensors＇ operating bandwidths heavily overlap. The SSD has been greatly mitigated.展开更多
A novel method of linear demodulation based on edge filter is presented. An experimental system is built up in which LPG is used as the edge filter. We achieve linear demodulation with a bandwidth of 5nm.
The mechanism of measuring temperature and strain using FBG has been studied deeply, however , signal demodulation has not been thoroughly solved. A novel demodulation system using CCD and a temperature sensing system...The mechanism of measuring temperature and strain using FBG has been studied deeply, however , signal demodulation has not been thoroughly solved. A novel demodulation system using CCD and a temperature sensing system are designed.展开更多
基金This work was supported by the National Natural Science Foundation of China under Grant No.60673152
文摘Optical fiber interferometric sensors based on [3×3] couplers have been used in many fields. A new technique is proposed to demodulate output signals of this kind of sensors. The technique recovers the signal of interest by fitting coefficients of elliptic （Lissajous） curves between each fiber pair. Different from other approaches, this technique eliminates the dependence on the idealization of [3×3] coupler, provides enhanced tolerance to the variance of photoelectric converters, and is anti-polarization in a certain extent. The main algorithm has been successfully demonstrated both by numerical simulation and experimental result.
基金supported by the Harbin Science Research Foundation under Grant No.2003AFQXJ004
文摘In order to increase the multiplexing density of the fiber Bragg gratings （FBGs） for a low cost per-sensor, based on the analysis of the spectrum shadow distortion （SSD）, a novel successive demultiplexing scheme for FBG sensors has been developed. It is based on the optical cade division multiple access （CDMA） balanced demodulation. A high-density multiplexing-demultiplexing system for FBG sensors has been designed, and corresponding simulation carried out has demonstrated that the FBG sensors＇ reflective signals can still be obtained accurately and respectively, even if FBG sensors＇ operating bandwidths heavily overlap. The SSD has been greatly mitigated.
基金Supported by the National '863' high technology project (2002 AA313110)
文摘A novel method of linear demodulation based on edge filter is presented. An experimental system is built up in which LPG is used as the edge filter. We achieve linear demodulation with a bandwidth of 5nm.
文摘The mechanism of measuring temperature and strain using FBG has been studied deeply, however , signal demodulation has not been thoroughly solved. A novel demodulation system using CCD and a temperature sensing system are designed.
