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High spatial frequency lamellar gratings are shown to function as phase compensators, quarter-wave and half-wave retarders, and polarization rotators that operate on specularly reflected (zeroth-order) beams . These gratings are designed using rigorous coupled-wave and modal grating diffraction theories . Controlling the geometrical parameters of these gratings allows for engineering the phase retardation and polarization conversion introduced to a reflected beam . Fabrication and operational 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 parameters .

A novel two-dimensional finite-difference time-domain simulation for treating the interaction of a focused beam with a rewritable optical disk is detailed and experimentally validated. In this simulation, the real material properties of the rewritable multilayer stack and the aperiodic nature of the disk topography are considered. Excellent agreement is obtained between calculated and measured push-pull tracking servosignals for magneto-optical disks with pregrooves and infinite-length preformat pits. To demonstrate the utility of the simulation as a design tool, the design process for a 0.9-µm track pitch, continuous, composite servoformat magneto-optical disk is given.

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Reflection of light from a high spatial frequency lamellar grating at a glass-air (Θ>Θc) or glass-metal interface introduces a phase shift between the orthogonal polarization components. If a conventional incidence geometry is used (grating vector parallel to the plane of incidence), no polarization conversion occurs. Thus, gratings of this type can be used as phase compensation and retardation elements operating on a specularly reflected beam.