Formation of surface relief gratings with homeotropically oriented photopolymer from a photocross-linkable organic monomer.

In this communication, we describe a simple process for the generation of surface relief gratings (SRG). SRG are fabricated from a photocross-linkable organic monomer PDACE (4-propyldiphenylacetylenecarboxylic acid cinnamyl ester) with cinnamyl ester and tolane groups, by using a patterned non-polarized UV light irradiation. The patterns of the surface relief structures can be easily controlled and the modulation depth can reach 130 nm. Moreover, it is interestingly observed that the photopolymer of the SRG exhibits distinctive characteristics including homeotropic orientation and fluorescence properties as a result of the photocross-linking of the dual photoreactive groups of PDACE. Finally, the mechanism of fabrication of SRG from PDACE is discussed with mean-field theory.