The designed parameters for an acoustooptics linear model modulator (AOSM) were given in this paper.Germanium crystal was used as acoustooptical material.The operating center frequency is 80MHz;7MHz 3db bandwidth were obtained.With 8W electrical output of AOSM driver,the efficiency of diffraction can reach to 36%.This device has been used as laser beam intensity modulator in Video/infrared dynamic image converting system.