Laser Optical Differentiation WFS design and lab characterization for SIGHT

SIGHT (Sharpening Images using Guidestars on the Hale Telescope) is an innovative concept for an integrated image sharpening system for the 200" (5.08m) diameter Hale Telescope at Palomar Observatory. When commissioned in 2023, SIGHT will be available for use with any single-object (< 30 arcsec field of view) Cassegrain instrument, for the first-time providing AO compensation spanning the wavelength range 360 nm - 1000 nm with 100% sky coverage. SIGHT is unique in several aspects including that it uses open-loop wavefront correction, UV Rayleigh laser guide star (RLGS) on a 5m aperture, and a novel laser generalized-Optical Differentiation Wavefront Sensor (LODWFS). The LODWFS provides a large, lineary dynamic range of wavefront phase measurement. Our wavefront sensor design uses five lenses, a KDP Pockels Cell as a fast optical shutter, two Wollaston prisms, and a custom liquid crystal polarization rotation mask. Simulation results of its performance show promising characteristics including little to no aliasing noise. In this proceeding, we show the design of the LODWFS, and the results of its laboratory component characterization.