Improvement of chirped pulse contrast using electro-optic birefringence scanning filter method

A method using scanning filter to improve the contrast of chirped pulse is proposed, and the principle of this method is analyzed. The scanning filter is compared with the existing pulse-picking technique and nonlinear filtering technique. The scanning filter is a temporal gate that is independent on the intensity of the pulses, but on the instantaneous wavelengths of light. Taking the electro-optic birefringence scanning filter as an example, the application of scanning filter methods is illustrated. Based on numerical simulation and experimental research, it is found that the electro-optic birefringence scanning filter can eliminate a prepulse which is several hundred picoseconds before the main pulse, and the main pulse can maintain a high transmissivity.