Polarizer holographic grating-based two-dimensional pupil expansion method

Abstract

The invention discloses a polarizer holographic grating-based two-dimensional pupil expansion method, replication and expansion of an exit pupil in a waveguide transmission process are used, to breakthrough a limitation of a Lagrange invariant on an FOV and an exit pupil size. The two parameters: the exit pupil size and the field of view are independent of each other by using a polarizer holographic grating, facilitating design and optimization. On the basis of one-dimensional pupil expansion, the polarizer holographic grating only needs to be added as a coupling turning element, to play a one-dimensional pupil expansion and plane turning role on light transmitted in waveguide, and a larger exit pupil range can be obtained. A proper waveguide entrance pupil size and a propagation angle are used to match waveguide thickness to achieve continuity between exit pupil beams. In addition, by superimposing polarizer holographic gratings of three colors of red, green, and blue, optical waveguide can realize color transmission, thereby improving a color expression capability of an optical waveguide device in a two-dimensional plane mode.

Description

technical field [0001] The invention relates to an exit pupil expandable method, in particular, a two-dimensional pupil expansion technology suitable for optical waveguide imaging based on a Polarization Volume Grating (PVG), which can realize color transmission and a large viewing angle at the same time. Background technique [0002] AR wearables, such as computers embedded in glasses or virtual technology goggles, project images directly in front of the user's eyes. In glasses-type devices, these projections are transparent so the user can see the projected data in the near field, leaving the far-field view of the real world largely unobstructed. A challenge for such AR wearables is to create a sufficiently large and continuous exit pupil. [0003] Extensible exit pupil is a major advantage of optical waveguide imaging technology. Like FOV, the exit pupil size is also an important indicator to measure the performance of an AR system. In the traditional visual optical sy...

AI Technical Summary

Problems solved by technology

[0008] The purpose of the present invention is to address the deficiencies of the prior art, and propose a two-dimensional pupil expansion method based on a polarized volume holographic grating, which solves the problem of the Lagrange invariant on the simultaneous increase of the viewing angle and the exit pupil size. , the two parameters of exit pupil size and field of view are independent of each other, which is convenient for independent design and optimization

Images