Study On The Double-Polarization Electro-Optical Q-Switched With Wide Beam

In the electro-optical Q-switched lasers, the single linearly polarized light is electro-optical Q-switched by electro-optic effect. Because of the thermal effect depolarization loss, the output energy of the laser will be instability, and the quality of the beam would be affected.This paper analyses thermal depolarization effect caused by thermally induced birefringence, and then establishes the mathematical model of the power change in the laser rod while the temperature changes. The thermal depolarization effect of laser is discussed qualitatively. As traditional electro-optical Q-switched pulsed laser is easily affected by thermo-depolarization effect with high repetition frequency, a novel Q-switched method is presented. The calcite has character of natural double reflection, and can be used as polarizing element to get non-linear-polarization pulsed laser. The method which broke down barriers of the calcite is inserting the telescope system in the cavity. The dual-polarization electro-optical Q-switched laser with wide beam is designed. It indicates from the experiment results that the stability of laser has been highly enhanced when running with high repetition frequency after using this novel Q-switched method, and it effectively solved thermal depolarization effect, improved output ratio of Q-switching to free running.