US 7,181,108 B2 · Method and optical system for coupling light into a waveguide

Abstract

A method and optical system for coupling light from an incoming light wave (WI) into a waveguiding substrate (S) arranges the light wave (WI) to interact with a diffractive in-coupling grating element or elements (IG) arranged on or embedded within the substrate (S) and arranged to couple the energy from the light wave (WI) into a waveguided light wave (WG). The polarization state of the light wave (WI) is converted after its first interaction (D1) with the in-coupling grating element/elements (IG) and before a second interaction (D2) with the grating element/elements (IG) takes place. The method minimizes any “reverse” diffractions, which would direct light back towards the front-end optics and therefore to increase the width W of the in-coupling grating/gratings (IG). Preferred embodiments include diffractive beam expanders for virtual displays.

Claims19

Dependent claims

A method comprising:

arranging an incoming light wave to interact with a diffractive in-coupling grating element or elements arranged on or embedded within a planar waveguiding substrate and arranged to couple energy from said incoming light wave into a waveguided light wave propagating within said substrate, and
converting the polarization state of the light wave after its first interaction with said in-coupling grating element or elements and before a second interaction with said in-coupling grating element or elements takes place.

Dependencies are inferred from the claim text.

Method and optical system for coupling light into a waveguide

Life of this patent

Method and optical system for coupling light into a waveguide

Life of this patent

Abstract

Claims19