Optical Design For A Holographic Scanning System

A lens design for generating holograms on a laser beam deflector is described. The deflector is a rotating cylindrical surface on which several transmission type volume holograms are recorded, analogous to a multifacetted rotating mirror. The holograms are recorded at a wavelength of 488.0 nm and reconstructed at 632.8. The reconstructed beam is required to be near diffraction limited on a flat field and have a linear scan with respect to the rotation of the cylinder over ±8 degrees. The resulting design is an air-spaced doublet with spherical surfaces which is used off-axis to the generating beam. The wavefront aberration in the reconstruction was reduced from 0.6 waves RMS to 0.06 waves RMS. The methods used for defining the hologram and designing the lens will be described.