An optically powered sensor for measuring pressure which is linked by optical fiber is developed in new scheme. Its pulse position modulation (PPM) optical signal and optical supply power for electronics in probe are...An optically powered sensor for measuring pressure which is linked by optical fiber is developed in new scheme. Its pulse position modulation (PPM) optical signal and optical supply power for electronics in probe are transmitted via a single optical fiber. The optical power is carried by a 1 300 nm laser diode (LD) and the sensing data are carried by a 850 nm LED. The remote probe uses all CMOS chips and particular modulations (PPM and PWM). Its electrical consumption including signal manipulation and LED driven current from optically converted is less than 100 μW. The laser diode supplies 5 mW optical power into the fiber. A photodetector converts sufficiently this power into electrical power to drive the whole probe operation. The optically powered distance gets up to 500 m. The novel sensor combines optical fiber and electronics technology into a system. Because of using the principle of ratio measurement between measured and reference signals, as well as light feedback,the system is available with high reliable, outstanding accuracy and repeatability.展开更多
This paper reports an application of an optical fiber sensor in a continuous and in situ failure testing of an E-glass/vinylester top hat stiffener （THS）. The sensor head was constructed from a compact phase-shifted...This paper reports an application of an optical fiber sensor in a continuous and in situ failure testing of an E-glass/vinylester top hat stiffener （THS）. The sensor head was constructed from a compact phase-shifted fiber Bragg grating （PS-FBG）. The narrow transmission channel of the PS-FBG is highly sensitive to small perturbation, hence suitable to be used in acoustic emission （AE） assessment technique. The progressive failure of THS was tested under transverse loading to experimentally simulate the actual loading in practice. Our experimental tests have demonstrated, in good agreement with the commercial piezoelectric sensors, that the important failures information of the THS was successfully recorded by the simple intensity-type PS-FBG sensor.展开更多
This paper reports on an experimental program of work which investigates the reliability, durability, and packaging of fiber Bragg gratings （FBGs） for application as distributed strain sensors during structural fati...This paper reports on an experimental program of work which investigates the reliability, durability, and packaging of fiber Bragg gratings （FBGs） for application as distributed strain sensors during structural fatigue testing of military platforms. The influence of the FBG fabrication process on sensor reliability is investigated. In addition, methodologies for broad-area packaging and surface-mounting of FBG sensing arrays to defense platforms are developed and tested.展开更多
文摘An optically powered sensor for measuring pressure which is linked by optical fiber is developed in new scheme. Its pulse position modulation (PPM) optical signal and optical supply power for electronics in probe are transmitted via a single optical fiber. The optical power is carried by a 1 300 nm laser diode (LD) and the sensing data are carried by a 850 nm LED. The remote probe uses all CMOS chips and particular modulations (PPM and PWM). Its electrical consumption including signal manipulation and LED driven current from optically converted is less than 100 μW. The laser diode supplies 5 mW optical power into the fiber. A photodetector converts sufficiently this power into electrical power to drive the whole probe operation. The optically powered distance gets up to 500 m. The novel sensor combines optical fiber and electronics technology into a system. Because of using the principle of ratio measurement between measured and reference signals, as well as light feedback,the system is available with high reliable, outstanding accuracy and repeatability.
文摘This paper reports an application of an optical fiber sensor in a continuous and in situ failure testing of an E-glass/vinylester top hat stiffener （THS）. The sensor head was constructed from a compact phase-shifted fiber Bragg grating （PS-FBG）. The narrow transmission channel of the PS-FBG is highly sensitive to small perturbation, hence suitable to be used in acoustic emission （AE） assessment technique. The progressive failure of THS was tested under transverse loading to experimentally simulate the actual loading in practice. Our experimental tests have demonstrated, in good agreement with the commercial piezoelectric sensors, that the important failures information of the THS was successfully recorded by the simple intensity-type PS-FBG sensor.
文摘This paper reports on an experimental program of work which investigates the reliability, durability, and packaging of fiber Bragg gratings （FBGs） for application as distributed strain sensors during structural fatigue testing of military platforms. The influence of the FBG fabrication process on sensor reliability is investigated. In addition, methodologies for broad-area packaging and surface-mounting of FBG sensing arrays to defense platforms are developed and tested.
