Vector vortex waveplates
AssigneeBeam Engineering for Advanced Measurements Co.
InventorsNelson Tabirian, Sarik Nersisyan
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Abstract
Method for fabrication of vector vortex waveplates of improved quality due to reduced singularity size and widened spectral band, the method comprising creating a boundary condition for vortex orientation pattern of a liquid crystal polymer on a substrate using materials with reversible photoalignment, equalizing exposure energy over the area of the waveplate by redistributing the energy of radiation used for photoalignment from the center of the beam to its peripheries, and using vector vortex waveplate as a linear-to-axial polarization converter. Fabrication of spectrally broadband vector vortex waveplates further comprises two or more liquid crystal polymer layers with opposite sign of twist.
Claims7
A photoalignment method for fabrication of liquid crystal vector vortex waveplates comprising:
- (a) a substrate;
- (b) means for rotating said substrate;
- (c) a material layer with reversible photoaligning capability coated over the surface of said substrate;
- (d) a light source with wavelength in the absorption band of said photoalignment material;
- (e) optical means for polarizing and projecting the energy of said light source over the layer of said photalignment coating on said rotating substrate;
- (f) optical means for shaping the beam in the form of a strip with its energy redistributed from the center of the beam to its peripheries.
Dependencies are inferred from the claim text.