Waveguides with peripheral side geometries to recycle light

A method for use within an optical waveguide including a bulk-substrate, an input-coupler and an output-coupler, the bulk-substrate of the optical waveguide including a first major side, a second major side opposite the first major side, and peripheral sides, the method comprising:

• coupling into the bulk-substrate of the optical waveguide, light corresponding to an image associated with an input-pupil, using the input-coupler of the optical waveguide;
• coupling out of the bulk-substrate of the optical waveguide, light corresponding to the image that has traveled through the optical waveguide from the input-coupler to the output-coupler at least in part by way of total internal reflection (TIR), using the output-coupler;
• and
• recycling a portion of the light corresponding to the image, that is incident on one of the peripheral sides that includes first and second surfaces that define first and second planes angled 45 degrees relative to one another, after the portion of the light corresponding to the image has traveled within the bulk-substrate of the optical waveguide in a propagation direction toward the one of the peripheral sides, the recycling performed using the first and second surfaces that define first and second planes angled 45 degrees relative to one another,
• wherein the first and second surfaces direct light incident on the first and second surfaces to the output-coupler for output in parallel with the light corresponding to the image.

A near-eye or heads-up display system, comprising:

• an optical waveguide including a bulk-substrate, an input-coupler and an output-coupler;
• a display engine configured to produce an image and to direct light corresponding to the image toward the input-coupler of the optical waveguide;
• the bulk-substrate of the optical waveguide including a first major side, a second major side opposite the first major side, and peripheral sides;
• the input-coupler of the optical waveguide configured to couple, into the bulk-substrate of the optical waveguide, light corresponding to the image;
• and
• the output-coupler of the optical waveguide configured to couple, out of the bulk-substrate of the optical waveguide, light corresponding to the image that has traveled through the optical waveguide from the input-coupler to the output-coupler at least in part by way of total internal reflection (TIR),
• wherein a peripheral side of the peripheral sides of the bulk-substrate of the optical waveguide includes first and second surfaces that define first and second planes angled 45 degrees relative to one another, and
• wherein the first and second surfaces direct light incident on the first and second surfaces to the output-coupler for output in parallel with the light corresponding to the image.