The pulse compressed grating (i.e. PCG) is the key optical element in high power laser system. In order to obtain the PCG with high diffraction efficiency, it is necessary to design the required structure parameters of the photo-resist grating which is used as the mask of fabricating the PCG in process of etching. The rigorous couple wave theory is adopted to study and search for the suitable structure parameters of the PCG with the 1740lp/mm space frequency and particular basement of dielectric stack films which could produce more than 97% diffraction efficiency. Then the required structure parameters of the mask which is corresponding to those suitable structure parameters of the PCG are determined under some etching technological conditions. In studying the relationship between the diffraction efficiency of the mask and its structure parameters, we found that we could estimate the structure parameters of the mask by its -1st order diffraction efficiency. Then a simple and practical method which can estimate the structure parameters of the photo-resist grating according to its diffraction efficiency is proposed. The measuring setup based on this method is built and the veracity of this method is verified by experiment. The experiment result is present in the paper.

Date Published: 9 November 2010
PDF: 6 pages
Proc. SPIE 7849, Optical Design and Testing IV, 78491Y (9 November 2010); doi: 10.1117/12.869920

Published in SPIE Proceedings Vol. 7849:
Optical Design and Testing IV
Yongtian Wang; Julie Bentley; Chunlei Du; Kimio Tatsuno; Hendrik P. Urbach, Editor(s)