Flat-top distribution of excimer laser using ultrasonic grating

摘要

A model to achieve flat-top distribution of ultraviolet (UV) excimer laser is presented. Reserving the practically lossless superiority in the traditional diffraction approach, the method improves a diffraction grating with a controllable grating period based on the acousto-optic diffraction effect. A theoretical analysis extending the Huygens-Fresnel principle and Gauss Schell model describing a typically partial coherent source of excimer is proposed, so that a fast Fourier transform numerical simulation could be utilized to calculate the optimized Raman-Nath comprehensive parameter of the acousto-optic medium. Such an excimer homogenous technology could be wisely used in UV lithography and micromachining.