The research of stretching-compressing system for ultrashort pulse under 3 dimensions

In the experiment of stretching & compressing for ultrashort pulse, it's necessary to introduce certain horizontally slanting angle. Comparing to the traditional paraxial approximating calculation of stretching- compressing system within 2 dimensions, a mathematical model of 3-dimension for stretching- compressing system is shown via getting each point's 3-d coordination with ray-tracing method. The relation between slanting angle and the total light path, group delay, group delay dispersion, etc are shown. Mutual compensation of each parameter in this system is also discussed. The output ray is approximately parallel to input ray, and the IR part of spectrum is more sensitive than the UV one to the slanting angle. With 0.1 degree changing of slanting angle, it's necessary to change the position of grating by 0.2 mm for compensation.