This paper reviews the studies on acoustoelectric effect in extrinsic semiconductor materials used in various scientific and other measurements. A historical review of earlier findings is given with special reference ...This paper reviews the studies on acoustoelectric effect in extrinsic semiconductor materials used in various scientific and other measurements. A historical review of earlier findings is given with special reference to associated mechanisms. Acoustoelectric studies in solid state devioes require further attention and the work done in this area is also discussed.展开更多
Laser shock peening is a well-known method for extending the fatigue life of metal components by introducing near-surface compressive residual stress. The surface acoustic waves （SAWs） are dispersive when the near-s...Laser shock peening is a well-known method for extending the fatigue life of metal components by introducing near-surface compressive residual stress. The surface acoustic waves （SAWs） are dispersive when the near-surface properties of materials are changed. So the near-surface properties （such as the thickness of hardened layers, elastic properties, residual stresses, etc.） can be analyzed by the phase velocity dispersion. To study the propagation of SAWs in metal samples after peening, a more reasonable experimental method of broadband excitation and reception is introduced. The ultrasonic signals are excited by laser and received by polyvinylindene fluoride （PVDF） transducer. The SAW signals in aluminum alloy materials with different impact times by laser shock peening are detected. Signal spectrum and phase velocity dispersion curves of SAWs are analyzed. Moreover, reasons for dispersion are discussed.展开更多
The interaction of multi-channel surface acoustic waves （SAWs） and a guided optical wave in fiber is studied, and the corresponding coupled wave equations are derived. A novel two-channel SAW all-fiber acousto-optic...The interaction of multi-channel surface acoustic waves （SAWs） and a guided optical wave in fiber is studied, and the corresponding coupled wave equations are derived. A novel two-channel SAW all-fiber acousto-optic modulator is designed, fabricated, and tested. The theoretical analysis is supported by the experimental results.展开更多
文摘This paper reviews the studies on acoustoelectric effect in extrinsic semiconductor materials used in various scientific and other measurements. A historical review of earlier findings is given with special reference to associated mechanisms. Acoustoelectric studies in solid state devioes require further attention and the work done in this area is also discussed.
基金supported by the National Natural Science Foundation of China under Grant No.60778006.
文摘Laser shock peening is a well-known method for extending the fatigue life of metal components by introducing near-surface compressive residual stress. The surface acoustic waves （SAWs） are dispersive when the near-surface properties of materials are changed. So the near-surface properties （such as the thickness of hardened layers, elastic properties, residual stresses, etc.） can be analyzed by the phase velocity dispersion. To study the propagation of SAWs in metal samples after peening, a more reasonable experimental method of broadband excitation and reception is introduced. The ultrasonic signals are excited by laser and received by polyvinylindene fluoride （PVDF） transducer. The SAW signals in aluminum alloy materials with different impact times by laser shock peening are detected. Signal spectrum and phase velocity dispersion curves of SAWs are analyzed. Moreover, reasons for dispersion are discussed.
基金supported by the National Natural Science Foundation of China(No.60572018)the Tianjin Science and Technology Developing Programs (Nos.05YFGPGX04900 and 07ZCKFGX00200)
文摘The interaction of multi-channel surface acoustic waves （SAWs） and a guided optical wave in fiber is studied, and the corresponding coupled wave equations are derived. A novel two-channel SAW all-fiber acousto-optic modulator is designed, fabricated, and tested. The theoretical analysis is supported by the experimental results.
