LAMELLAR GRATINGS AS POLARIZATION COMPONENTS FOR SPECULARLY REFLECTEDBEAMS

High spatial frequency lamellar gratings are shown to function as phas e compensators, quarter-wave and half-wave retarders, and polarization rotators that operate on specularly reflected (zeroth-order) beams. T hese gratings are designed using rigorous coupled-wave and modal grati ng diffraction theories. Controlling the geometrical parameters of the se gratings allows for engineering the phase retardation and polarizat ion conversion introduced to a reflected beam. Fabrication and operati onal tolerances for these elements are discussed. Wavelength and polar angle of incidence variation affect the performance of these elements more strongly than variations in other geometrical and operational pa rameters.