Recently the possibility to record phase diffractive optical elements (DOEs) onto photopolymers has been explored. Two of their properties when they are illuminated are useful to this goal: the relief surface changes and the refractive index modifications. The recording intensity distribution with a sinusoidal profile is the easiest profile to record in a holographic recording material, i.e. it can be obtained by the simple interference of two plane wave beams or alternatively using a spatial light modulator. This second method is more flexible and opens the possibility to record a wide range of diffractive elements such as binary, blazed gratings, diffractive lenses, etc. Sharp profiles may as well be recorded. In general they present a clear smoothing of the edges due to various reasons: the cut-off frequency (a low pass filtering) of the optical system, quality of the spatial light modulation, inhibition period, finite size of polymer chains, monomer diffusion, and non-linearities in the recording process. In this work we have analyzed the importance of some of these aspects of the photopolymer and the experimental set-up in order to record high quality DOEs. The photopolymer analyzed is based on polyvinylalcohol/acrylamide. To achieve this goal we have used a diffusion model to simulate the DOE’s recording with different recording intensities distributions.

Date Published: 26 September 2013
PDF: 8 pages
Proc. SPIE 8855, Optics and Photonics for Information Processing VII, 88550V (26 September 2013); doi: 10.1117/12.2023861

Published in SPIE Proceedings Vol. 8855:
Optics and Photonics for Information Processing VII
Khan M. Iftekharuddin; Abdul A. S. Awwal; Andrés Márquez, Editor(s)