Abstract: In this paper,the design of an AO device Whose central frequency is 300 MHz is given.This device uses lead molybdate or paratellurite as the acousto-optic medium and tin as the adhesive layer between the transducer and the AO medium.The frequency response of the piezo-electric transducer and the transducer bandwidth are calculated and the layers' thickness is chosen.The total bandwidth of this device reaches 200 MHz,resulting in a time-bandwidth product(TB product)of 1000, which fulfils the elementary requirements of AO signal processing and AO optical computer.