Waveguide-type Multidirectional Light Field Display

Abstract

We demonstrate two types of light field displays based on waveguide grating coupler arrays: a line beam type and a point source type. Ultra violet imprinting of an array of diffractive nanograting cells on the top surface of a 50-μm-thin slab waveguide can deliver a line beam or a point beam to a multidirectional light field out of the waveguide slab. By controlling the grating vectors of the nanograting cells, the waveguide modes are externally coupled to specific viewing angles to create a multidirectional lightfield display. Nanograting cells with periods of 300 nm–518 nm and slanted angles of −8.5°–+8.5° are fabricated by two-beam interference lithography on a 40 mm × 40 mm slab waveguide for seven differ-ent viewpoints. It is expected that it will be possible to realize a very thin and flexible panel that shows multidirectional light field images through the waveguide-type diffraction display.