Optical elements with spatially varying transmission are required for laser engineering and imaging systems. Although
refractive systems can transform the Gaussian energy distribution of a laser beam into a "top-hat" distribution, they lack
the versatility to produce the more-complex and precise intensity distributions required for high-peak-power laser
systems such as the OMEGA and OMEGA EP Laser Systems at the University of Rochester's Laboratory for Laser
Energetics and the National Ignition Facility at Lawrence Livermore National Laboratory. Previously, distributions of
opaque metal pixels on a transparent glass substrate have been used for such beam-shaping efforts, but laser-damage
thresholds of the order of 200-700 mJ/cm2 in the nanosecond regime limit their applicability. By applying
photolithographic patterning of coumarin-based photoalignment layers using polarized UV light to generate spatially
varying molecular orientation in a nematic liquid crystal (LC) device, we have developed and demonstrated highresolution
beam-shaper devices for such high-peak-power laser applications in the near-IR region. Operating at 1054 nm,
these devices demonstrated a contrast ratio ranging from 280:1 to 540:1, a pixel size of 10 m with an interpixel
resolution of 1.7 μm, and laser-damage resistance ranging from 20 to 40 J/cm2 at 1054 nm (1-ns pulse width) using a
10-μm layer of commercially available nematic LC materials. Coupled with the ability to generate an almost infinite variety
of binary and gray-scale apodization and beam-shaping profiles by the photoalignment process, the high laser-damage
threshold of these devices makes them attractive and useful tools for a multitude of laser applications.
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