Complex Diffractive Optical Elements Stored in Photopolymers.

Roberto Fernández,Cristian Neipp,Eva Calzado,Marta Morales-Vidal,Jorge Francés,Andrés Márquez,Augusto Beléndez,Sergi Gallego

doi:10.3390/polym11121920

Abstract

We study the recording of complex diffractive elements, such as achromatic lenses, fork gratings or axicons. Using a 3-D diffusion model, previously validated, we are able to predict the behavior of photopolymer during recording. The experimental recording of these complex elements is possible thanks to a new generation spatial light modulator capable of generating periodic and aperiodic profiles. Both experimental and theoretical are analyzed and compared. The results show not only the good response of theoretical model to predict the behavior of the materials, but also the viability of photopolymers to store these kind of elements.

Highlights

The advantages of photopolymers as recording media for holographic applications and fabrication of photonic devices, such as waveguides, diffractive optical elements (DOEs) or 2-dimensional photonic structures have been widely discussed [1,2,3]
We evaluated the suitability of our diffusion model to simulate the recording of different complex DOEs, such as fork gratings, diffractive axicons, achromatic lenses, and helicoidal axicons in a polyvinyl alcohol/acrylamide (PVA/AA)-based photopolymer
To validate the results obtained through the model, we recorded experimentally these complex DOEs thanks to a setup based on a LCoS spatial light modulator (SLM)

Summary

Introduction

The advantages of photopolymers as recording media for holographic applications and fabrication of photonic devices, such as waveguides, diffractive optical elements (DOEs) or 2-dimensional photonic structures have been widely discussed [1,2,3]. One of the most used materials for these applications is the one based on polyvinyl alcohol/acrylamide (PVA/AA) This material showed outstanding characteristics [4,5,6] and interesting results were obtained in our firsts approaches to complex DOEs recording such as blazed gratings [7] or diffractive lenses [8]. High quality point spread function (PSF) was obtained for particular wavelength These elements are intended only for applications with monochromatic light sources. On this basis, it is interesting to count on achromatic lenses, or achromats, which shows the same behaviour for different wavelengths. Thanks to DOE’s advantages and its capability of performing different functions simultaneously, it is possible to multiplex various lenses in the same DOE by using different multiplexing schemes [10,11,12]

Methods

Results

Conclusion