Laser Beam Apodizer Utilizing Gradient-Index Optical Effects in CholestericLiquid Crystals

摘要

The fabrication of laser beam apodizers (or soft apertures) with large clearapertures using cholesteric liquid crystals is described. A soft edge profile is achieved by filling a cell with two separate cholesteric liquid crystal mixtures with different selective reflection bands. The fluid-like property of liquid crystals allows them to mix at the interface. In this overlap region, the reflectivity changes as a function of position. This concept is applied to the fabrication of two devices: (1) a one-dimensional beam apodizer with a clear aperture that can be mechanically adjusted by sliding two complementary devices relative to each other and (2) a circular beam apodizer.