of the molecularly reoriented direction in surface relief holographic
gratings using photoreactive
liquid crystalline copolymers, N. Kawatsuki, A. Tashima, A. Emoto, H. Ono, M. Kondo, M. Okada, and S. Matsui, Jpn. J. Appl. Phys. 50 (2011) 081608.
|Molecularly oriented surface relief (SR)
structures in photo-crosslinkable liquid crystalline copolymer films
were fabricated using a 325 nm He–Cd laser with p-p and s-s polarized
intensity holographic beams. The SR height increased as the exposure
energy increased. In contrast, the molecular orientation structure
depended on the exposure dose. For all doses, molecular migration from
the lower exposure region to the higher one was due to the difference
in the crosslinking density. The SR height reached up to 280 nm for a
film that was initially 1.0 µm thick. The diffraction efficiency
depended on the fabricated SR grating, while the difference in the
molecular reorientation area and the direction of the SR gratings
explained the diffraction properties.