Abstract: An eye-tracking system is provided. The system includes an at least partially transparent visible light waveguide having a visible light display region configured to emit visible light to impinge upon an eye of a user. A light source is configured to emit at least infrared (IR) light that travels along an IR light path to impinge on the eye. A microelectromechanical system (MEMS) scanning mirror positioned in the IR light path is configured to direct the IR light along the IR light path. A relay positioned in the IR light path downstream of the MEMS scanning mirror includes at least one mirror configured to reflect the IR light along the IR light path. At least one sensor is configured to receive the IR light after being reflected by the eye.

Abstract: A display device system includes a display engine and optical waveguide. The display engine includes an image former, that produces light corresponding to an image, and one or more lens groups that collimate the light corresponding to the image and outputs the light from the display engine. Each lens group includes one or more lenses that share a mechanical axis. The light corresponding to the image produced by the image former has an optical axis ray coincident with a principal ray of the light that originates at a center of the image produced by the image former. At least one lens group has its mechanical axis tilted relative to the optical axis ray of the light corresponding to the image produced by the image former, to prevent a ghost image from being formed by light corresponding to the image that is reflected-back from the waveguide toward the display engine.

Abstract: An apparatus, for use in replicating an image associated with an input-pupil to an output-pupil, comprises an optical waveguide including a bulk-substrate, an input-coupler and an output-coupler. The bulk-substrate includes first and second major sides and peripheral sides. The input-coupler couples, into the waveguide, light corresponding to the image associated with the input-pupil. The output-coupler couples, out of the waveguide, light corresponding to the image that has traveled through the waveguide from the input-coupler to the output-coupler at least in part by way of TIR. At least one of the peripheral sides includes first and second surfaces that define first and second planes angled 45 degrees relative to one another. Such a peripheral side provides for effective recycling of light that would otherwise leak out of the waveguide through the peripheral side.