Open AccessImproving vector vortex waveplates for high-contrast coronagraphy
Author(s) -
Sarik R. Nersisyan,
Nelson V. Tabiryan,
Dimitri Mawet,
Eugene Serabyn
Publication year - 2013
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.21.008205
Subject(s) - optics , vortex , polarization (electrochemistry) , optical vortex , light beam , topological quantum number , circular polarization , materials science , beam (structure) , physics , microstrip , chemistry , quantum mechanics , thermodynamics
Vector vortex waveplates (VVWs) open the door to new techniques in stellar coronagraphy and optical communications, but the performance of currently available liquid-crystal-polymer-based VVWs tends to be limited by defects in the axial region of the vortex pattern. As described here, several steps allow for a reduction in the size of such axial defects, including the use of photoalignment materials with high photosensitivity and reversible response, and a reduction in exposure energy. Moreover, redistributing the writing beam's intensity from the axial region to its periphery (using a VVW) allows the production of large area VVWs with a small defect area. Finally, using VVWs as linear to axial polarization converters allows producing VVWs of higher topological charge, while also reducing the photoalignment time to a few minutes. These steps have allowed the fabrication of VVWs with topological charges of 1 and 2 with central defect sizes below 3 μm.