3-dimensional modelling of the DOEs formation in PVA/AA photopolymers

Abstract

Photosensitive materials and optical information processing technologies based on holographic and photonic techniques are suffering a huge improvement. Furthermore Spatial Light Modulators (SLMs) based on LCoS microdisplays (PALCoS) open new possibilities to modulate the wavefront of a light beam. The improving of the models of the photopolymers as optical recording material together with the modelling of PALCoS, high resolution reflective devices, make possible the generation and recording of Diffractive Optical Elements (DOE) on the photosensitive materials. This DOEs have many important applications in photonics, communications of optical information processing. Working with a setup based on a LCoS display as a master, we can store complex DOEs. We used in this work PVA/AA based on acrylamide with coverplating and index matching system to avoid the influence of the thickness variation on the transmitted light in the material. With the 3-Dimensional diffusion model we can predict the DOE properties before recording and optimize the recording time and the exposure dose. Experimental data is compared with the simulation results to evaluate the accuracy of our model to reproduce the recording of any kind of complex DOE onto a photopolymer. This allows us to choose the appropriate characteristics for the material depending on the application and evaluate the influence of different parameters involved in the DOE generation. In this work we evaluate the simulation of the recording of optical vortexes, axicons, fork gratings and diffractive lenses comparing with the results using our experimental set-up.