Abstract: This paper will revisw the principles, design and applications of the acoustooptic devices using guided optical waves and acoustic surface waves. It will contain the propagation characteristics of the guided optical waves and of the acoustic surface waves, the acoustooptic interaction between these two waves, the theory of the interdigital transducer and the transducer bandwidth, the Bragg bandwidth and the design of these devices, the various applications of these devices especially in optical signal processing. This paper will be presented in two parts, the first part will concern mainly the principles and the second part mainly the design, the bandwidth of the device and the applications.