Abstract
We used high voltage to make a periodically poled crystal, and the QPM(quasi-phase matching) technique not only expands the applications in many domain but also get up the conversion efficiency of non-linear optics. Using the second harmonic generation(SHG) got the green light laser could apply to the military, long distance measurements, full colors display and data storage. The dissertation was devoted to fabricating periodically poled Lithium Niobate, Lithium Tantalite and 5% Mgo doped Lithium Niobate crystal. In order to get periodically poled crystals, we test the coercive field, stabilization time and parameters on other fabrications. In finally, we had succeeded in fabricating PPLT, PPLN and PPMgo:CLN. Considering about the optical damage threshold and non-linear coefficient, so we choose the 5% Mgo doped Lithium Niobate and using multiple pulses fabricated 3cm-long, 5.5mm-width and 1mm-thickness PPMgo:CLN to generate green light laser. When pumped with the pulse laser 1064 nm and fiber laser 1543 nm and 1539 nm into the OPA, the OPA generates 1064 nm beat wave into PPMgo:CLN (the temperate of the oven is 80oC) produces 532 nm beat wave. Considering no the loss of the reflector, the total conversion efficiency is about 38%.