Study Of Nonlinear Interferometer Based On GaAs

Laser interferometry has the advantages of high sensitivity and accuracy. It plays an important role in production and scientific research. Nowadays, with the development of the performance of various laser devices, the emerging of high-performance optoelectronic converters, and the wide application of new signal processing circuit and computer technology, the performance of the laser interferometer also develops significantly and has already been widely used in many different fields. However, since the optical measurement is easily disturbed by the surrounding environment, it is significant to research and development the laser interferometer with high-resolution and high-precision that can resist the disturbance of surrounding environment. In recent years with the development of nonlinear optics, the nonlinear interferometer that uses nonlinear optical effects develops rapidly. Using it to measure small vibration has the advantages of non-contact, no damage, high resolution of space and time, and resistance to environmental disturbance. So it is of great development prospects.In this dissertation, using piezoelectric ceramic oscillator, we have set up the experimental system of GaAs-based photo-induced electromotive force (photo-EMF) interferometer, and have improved and optimized the experimental system. We have measured the vibration signal of less than 1μm amplitude with the piezoelectric ceramic's driving frequency from 0.2KHz to 90KHz, and have analyzed the relationship between the photo-induced current and the intensity of the signal light and reference light, their intensity ratio and the angle between these two beams, the driving voltage and driving frequency of the piezoelectric ceramics, and the distance between the two electrodes at the surface of GaAs. Then we have compared our results with PDV100 laser vibrometer. Our experimental results coincide with theoretical formula as well as the results of PDV100. These works are of instructive meaning to use photo-EMF to achieve the detection of laser ultrasonic and to research and develop the laser ultrasonic system.