A number of new tunable, and solid state lasers such as Ti:Sapphire, external cavity diode laser, laser diode pumped Yag, YLF and a host of other lasers, have created new laser configurations that would require high frequency mode locking devices to produce picosecond mode locked laser pulses. The purpose of this study is to propose selecting LiNbo3 as the most efficient high frequency acousto-optic mode locking resonator for active mode locking of these new lasers. Lithium Niobate crystals from Japan and China have improved qualities, and may have more desirable optical and acoustic properties, and we are among the first in the U.S. to obtain such crystals. We have further proposed a unified theory on high Q acoustic resonators such that all interacting parameters can be analyzed simultaneously, and calculate parameters such as the instantaneous power, optimum resonator length, etc. in relation to the drive power. Based on the analysis to be developed in this project, we will then demonstrate a 500 MHz (for 1 GHz laser cavity) high Q liNbo3 acoustic standing mode locking device with a closed loop phase detection to monitor the mode locker resonant frequency by controlling the temperature of the mode locker.