Polarization Film Assemblies for Diffractive Waveguide Artifact Control

The patent applies a polarizing filter to change the polarization state parameter of incident light. By filtering light to a specific polarization state before it reaches the diffraction grating, the system maintains the grating's ability to expand the exit pupil while reducing rainbow artifacts caused by wavelength-dependent diffraction angles. The polarizing filter modifies the light's polarization parameter to achieve more uniform diffraction across the visible spectrum.

The patent combines a polarizing filter with the diffraction grating structure to create a composite optical system. This composite approach integrates two different optical mechanisms (polarization filtering and diffraction) into a single system that simultaneously achieves exit pupil expansion while minimizing rainbow artifacts through the complementary action of the polarizing filter.

The patent uses a polarizing filter to change the polarization state of light propagating in the waveguide. By controlling the polarization parameter of light, the system maintains wide field of view through the waveguide while preventing forward light leakage. The polarized light interacts with the diffraction grating in a controlled manner that directs light toward the user's eye while blocking forward propagation.

The polarizing filter acts as an intermediary element between the light source and the diffraction grating. It mediates the light's polarization state before diffraction occurs, enabling the system to achieve both wide field of view and prevention of forward light leakage by controlling how light interacts with subsequent optical elements in the waveguide.