Characterization and comparison of different photopolymers for low spatial frequency recording

• We analyze 3 different photopolymer (six different chemical compositions).
• We calculate the surface and internal diffusion in photopolymers.
• By index matching we see the influence of the refractive index modulation.
• We study the minimum thickness required to achieve a phase depth of 2π.

Free-radical photopolymer materials can be fabricated using a wide range of monomers, binders, dyes, etc. It was shown that in some photopolymers the surface and the internal diffusion for acrylamide materials are very different and also it was demonstrated the viability of acrylamide materials to achieve 2π phase depth for low spatial diffractive optical elements. Building on the work developed previously, in this paper, a characterization and a comparison is carried out for three different photopolymers: crosslinked acrylamide based photopolymers, a biophotopol and an H-PDLC material. We have measured the motion of the components inside the material and through the surface using a new index matching component and through the surface. We have studied the introduction of different crosslinkers in order to increase the refractive index modulation and to reduce the thickness required to achieve a phase depth higher than 2π in the diffraction optical elements.