Single-step fabrication of diffraction gratings on hybrid sol–gel glass using holographic interference lithography

Abstract

Single-step fabrication of diffractive surface relief gratings on an ultraviolet (UV) sensitive hybrid sol–gel glass is presented. The gratings are imprinted on the negative-tone sol–gel glass based on a holographic interference lithographic system. Characteristics of the sol–gel glass including refractive index and film thickness have been discussed and experimental results are presented as a function of baking temperature and UV exposure time respectively. The grating relief profiles are measured by an atomic force microscope and the measured groove depths are found in good agreement with the theoretical results determined by the Gerchberg–Saxton phase retrieval algorithm. It is promising to utilise the new material for various diffractive optical elements fabrication.