Fiber Acousto-optic Characteristics Of Study

By studying acousto-optical characteristics of the optical fiber, a new Q-switched method is proposed and the correlative experiments are designed.Began with acousto-optic interaction coupled wave equation and use the theory of the momentum match and mismatch between the polarization wave and the free waves of medium, acousto-optic interaction law and the diffraction efficiency formula is analysised. From the diffraction efficiency formula, it can be found that in order to improve diffraction efficiency, ultrasonic power and the length of transducer, and decrease of the width of transducer can be increased. Therefore, the experiment should be designed according to the points mentioned above.In addition, to verify the feasibility of the experiment, ANSYS simulation software was used to do a simple optical fiber in the sound field on the force of the simulation model. According to the model it could be found that when the acousto-power is increased to a higher number, then the fiber core is shattered and, therefore, ultrasonic power can not be added too much. Thus, appropriate ultrasonic power and the appropriate transducer size must be made strictly calculations.According to the transmission line of Mason equivalent circuit theory, the metallic membrane plating structure of piezoelectric transducer is determinated. Then, the length, width and thickness of piezoelectric transducer are calculated.Based on the above work and the status of current research on the interna, a new method of using piezoelectric transducer arrays was proposed to achieve a continuous acousto-optic diffraction Q-switch, designed an experimental program, designed and produced RF signal circuitry, and to prepare the control software, so that make the process of all experiment to be automatic. Then the experimental system can be set up and test data can be test, and finally the experimental results were analyzed.