title: Polarization-invariant grating based on a photoaligned liquid crystal in an oppositely twisted binary configuration.
abstract: We demonstrate a polarization-invariant liquid-crystal (LC) grating in an oppositely twisted and mutually orthogonal configuration. The polarization-invariant LC grating with high diffraction efficiency is fabricated using a single-masking process with two-step exposure of a linearly polarized ultraviolet light. It is found that the zeroth- and the first-order diffracted beams are linearly polarized and perpendicular to each other irrespective of the incident polarization for the phase retardation of m pi (m=integer).
authors.affiliation: School of Electrical Engineering 032, Seoul National University, Kwanak, P.O. Box 34, Seoul 151-600, South Korea.
authors.forename: Chang-Jae
authors.initials: CJ
authors.lastname: Yu
authors.forename: Dong-Woo
authors.initials: DW
authors.lastname: Kim
authors.forename: Jinyool
authors.initials: J
authors.lastname: Kim
authors.forename: Sin-Doo
authors.initials: SD
authors.lastname: Lee