EFFECTS OF PROCESS ERRORS ON THE DIFFRACTION CHARACTERISTICS OF BINARY DIELECTRIC GRATINGS

The effects of fabrication errors on the predicted performance of surf ace-relief phase gratings are analyzed with a rigorous vector diffract ion technique. For binary elements, errors in the dimensions of the pr ofile [depth, linewidth (fill factor), and grating period], as well as errors in the shape of the profile, are investigated. It is shown tha t the dimension errors do not have a significant effect on grating per formance when the grating is designed for either maximum or minimum di ffraction efficiency. A trapezoid is used to model the shape error of the profile. For the first time, design rules that significantly reduc e the effects of any shape error are presented.