Near-field optical characteristics of sub-wavelength grating irradiated by ultra-short optical pulse

摘要

We present a method for near-field analysis of ultra-short optical pulse propagation in the sub-wavelength grating based on the integration of Fourier spectrum decomposition and Fourier modal method. By using this method, near-field optical distribution within a high-efficiency reflective grating based on total internal reflection (TIR) is calculated as the irradiation source is a 200fs optical pulse with central wavelength of 1053nm. Electric field enhancement within the TIR grating is analyzed for both TE- and TM-polarized pulses. Methods of controlling the peak intensity in the grating ridge are also presented.