Abstract: Techniques are provided to re-arrange the placement of a photodiode within an illumination system to achieve improved characteristics and reduced form factor. An illumination system includes a laser assembly, a MEMS mirror system, a beam combiner, and a photodiode. The laser assembly includes RGB lasers, and the MEMS mirror system redirects laser light produced by the RGB lasers to illuminate pixels in an image frame. The beam combiner combines the laser light. The photodiode is provided to determine a power output of the laser assembly by receiving and measuring some of the laser light. The photodiode may be beneficially positioned before or after collimating optics and/or the beam combiner.

Abstract: A MEMS scanner may include a first flexible arm extending substantially in a forward direction and a base connected to a proximal end of the first flexible arm, the base being thicker than the first flexible arm in a vertical direction. The MEMS scanner may further include a second flexible arm connected to a distal end of the first flexible arm, the second flexible arm extending substantially in a reverse direction. The MEMS scanner may further include a mirror coupled to a distal end of the second flexible arm. In one implementation, the MEMS scanner may be a non-resonant scanner.

Abstract: An integrated optical beam steering system is configured in three stages to provide beam steering for image light from an imager (e.g., laser, light emitting diode, or other light source) to downstream elements in a display system such as an exit pupil expander (EPE) in a mixed-reality computing device. The first stage includes a multi-level cascaded array of optical switches that are configurable to spatially route image light over a first dimension of a two-dimensional (2D) field of view (FOV) of the display system. The second waveguiding stage transfers the image light along preformed waveguides to a collimator in the third stage which is configured to collimate the image light along the first dimension of the FOV (e.g., horizontal). The waveguiding and collimating stages may be implemented using lightweight photonic crystal nanostructures.

Abstract: Examples are disclosed that relate to scanning mirror systems for display devices. One example provides a display device comprising a light source, a support structure, and a scanning mirror system comprising a mirror, a first anchor located at a first lateral side of the scanning mirror system, a second anchor located at a second lateral side of the scanning mirror system, and a flexure. The flexure comprises a first portion extending from the first anchor toward a first longitudinal end and turning to meet a first end of the mirror, and a second portion extending from the second anchor toward a second longitudinal end and turning to meet to a second end of the mirror opposite the first end. The scanning mirror system further comprises an actuator system configured to actuate the flexure to thereby vary a scan angle of the mirror.

Abstract: An integrated optical beam steering system is configured in three stages to provide beam steering for image light from an imager (e.g., laser, light emitting diode, or other light source) to downstream elements in a display system such as an exit pupil expander (EPE) in a mixed-reality computing device. The first stage includes a multi-level cascaded array of optical switches that are configurable to spatially route image light over a first dimension of a two-dimensional (2D) field of view (FOV) of the display system. The second waveguiding stage transfers the image light along preformed waveguides to a collimator in the third stage which is configured to collimate the image light along the first dimension of the FOV (e.g., horizontal). The waveguiding and collimating stages may be implemented using lightweight photonic crystal nanostructures.

Abstract: Techniques are provided to re-arrange the placement of a photodiode within an illumination system to achieve improved characteristics and reduced form factor. An illumination system includes a laser assembly, a MEMS mirror system, a beam combiner, and a photodiode. The laser assembly includes RGB lasers, and the MEMS mirror system redirects laser light produced by the RGB lasers to illuminate pixels in an image frame. The beam combiner combines the laser light. The photodiode is provided to determine a power output of the laser assembly by receiving and measuring some of the laser light. The photodiode may be beneficially positioned before or after collimating optics and/or the beam combiner.

Abstract: Techniques are provided to reduce the form factor of laser-based systems by multi-purposing a photodiode used to help control the output of a laser. A reflective photodiode comprises a light receiving surface and a reflective coating. The light receiving surface is configured to absorb some incident light and to convert it into electrical current. The reflective coating is disposed on the light receiving surface and is configured to reflect some of the incident light away from the light receiving surface. The reflective coating also permits some of the incoming light to pass therethrough for absorption.

Abstract: A light engine comprises a liquid crystal on silicon (LCOS) panel that is operated in combination with illumination and imaging optics to project high-resolution virtual images into a waveguide-based exit pupil expander (EPE) that provides an expanded exit pupil in a near-eye display system. In an illustrative example, the illumination optics comprise a laser that produces illumination light that is reflected by a MEMS (micro-electromechanical system) scanner using raster scanning to post-scan optics including a microlens array (MLA) and one or more collimating or magnifying lenses before impinging on the LCOS panel. The LCOS panel operates in reflection in combination with imaging optics, including one or more of beam-steering mirror and beam splitter, to couple virtual image light from the LCOS panel into the EPE.

Abstract: Examples are disclosed that relate to actuator frames for scanning mirror systems. In one example an actuator frame for a scanning mirror assembly comprises a mounting member comprising a first side and an opposite second side. A first moveable member comprises a first interior side that defines a first gap and a second gap with the first side of the mounting member. A second moveable member comprises a second interior side that defines a third gap and a fourth gap with the second side of the mounting member. A first hinge connects a central portion of the mounting member with the first moveable member, and a second hinge connects the central portion of the mounting member with the second moveable member.

Abstract: Systems and methods are utilized for performing geometric multiplexing in MEMS display systems that utilize RGB laser diodes and MEMS mirrors to compensate for angular separation between the RGB light that results from passing the RGB light emitted from the RGB laser diodes through a single collimating lens shared by the RGB laser diodes, as opposed to utilizing a separate collimating lens for each corresponding laser diode. Spatial offsets between the RGB light at the target display, resulting from the angular separation, are compensated for by applying temporal buffers to the pulsing of the RGB laser sources so that the RGB light is horizontally and vertically aligned at the appropriate pixels of the target display during scanning by the MEMS mirrors system.

Abstract: An input-coupler of an optical waveguide includes one or more Bragg polarization gratings for coupling light corresponding to the image in two different directions into the optical waveguide. The input-coupler splits the FOV of the image coupled into the optical waveguide into first and second portions by diffracting a portion of the light corresponding to the image in a first direction toward a first intermediate component, and diffracting a portion of the light corresponding to the image in a second direction toward a second intermediate component. An output-coupler of the waveguide combines the light corresponding to the first and second portions of the FOV, and couples the light corresponding to the combined first and second portions of the FOV out of the optical waveguide so that the light corresponding to the image and the combined first and second portions of the FOV is output from the optical waveguide.

Abstract: The present disclosure generally relates to a method, and apparatus implementing the method for removing particulate accumulation from an optical element of a micro electromechanical systems (MEMS) package. The method may select a cleaning mode based, at least in part on, one or more of output of a sensor or a maintenance routine. Cleaning modes may include actuating, using an actuator of the MEMS package, one of a plurality of motion modes across the optical element. Optionally, the cleaning mode may include applying, using a power source of the MEMS package, a charge to the optical element. The disclosed techniques may enable the MEMS package to automatically and dynamically remove particulate matter without introducing additional mechanical elements.

Abstract: Examples are disclosed that relate to scanning display systems. One example provides a display device comprising a controller, a light source, and a scanning mirror system. The scanning mirror system comprises a scanning mirror configured to scan light from the light source in at least one direction at a resonant frequency of the scanning mirror, and an electromechanical actuator system coupled with the scanning mirror and being controllable by the controller to adjust the resonant frequency of the scanning mirror.

Abstract: A display system includes a waveguide having a first diffractive optical element and a second diffractive optical element. The waveguide is configured to receive a display light having a pupil height and pupil width and transmit the display light to an eyebox with an eyebox height and an eyebox width. The first diffractive optical element is configured to in-couple the display light into the waveguide, the first diffractive optical element having a first diffractive optical element height that is at least the pupil height and a first diffractive optical element width that is at least the eyebox width.

Abstract: Variable attenuation of an illumination source is provided by an aperture (i.e., an opening in a structure through which light passes) that is sandwiched between two tunable lenses that are configured to apply varying amounts of optical power. A controller operates the first tunable lens to apply optical power to the light to be divergent at the aperture structure so that a portion of the light is clipped. Varying the applied optical power at the first tunable lens can increase or decrease divergence at the aperture structure to thereby increase or decrease clipping and the attenuation of the light. The controller operates the second tunable lens to compensate for changes in light state at the first tunable lens by applying opposite optical power so that collimated light from the illumination source which enters the first tunable lens may exit the second tunable lens in the same collimated state.

Abstract: The present disclosure generally relates to a method, and apparatus implementing the method for removing particulate accumulation from an optical element of a micro electromechanical systems (MEMS) package. The method may select a cleaning mode based, at least in part on, one or more of output of a sensor or a maintenance routine. Cleaning modes may include actuating, using an actuator of the MEMS package, one of a plurality of motion modes across the optical element. Optionally, the cleaning mode may include applying, using a power source of the MEMS package, a charge to the optical element. The disclosed techniques may enable the MEMS package to automatically and dynamically remove particulate matter without introducing additional mechanical elements.

Abstract: A display system for presenting visual information to a user includes a fast scan mirror, a slow scan mirror, and anamorphic relay optics positioned optically between the fast scan mirror and slow scan mirror. The fast scan mirror has a fast scan arc in a scan direction of a display light provided by a light source. The slow scan mirror has a slow scan arc in a cross-scan direction of the display light that is perpendicular to the scan direction. The anamorphic relay optics are configured to magnify the display light in the cross-scan direction.

Abstract: Examples are disclosed that related to scanning image display systems. In one example, a scanning display system comprises a laser light source comprising two or more offset lasers, a scanning mirror system configured to scan light from the laser light source in a first direction at a higher frequency, and in a second direction at a lower frequency to form an image, and a controller configured to control the scanning mirror system to scan the laser light an interlaced pattern to form the image, and to adjust one or more of a scan rate in the second direction and a phase offset between a first frame and a second frame of the interlaced image.

Abstract: A display system includes a first light source, a second light source, at least one movable mirror, and an attenuator. The first light source is configured to provide a first light in a first optical path. The second light source is configured to provide a second light in a second optical path. A portion of the second optical path overlaps the first optical path in an overlapping portion. The attenuator is positioned in at least the first optical path and configured to attenuate at least the first light. The movable mirror is movable to deflect the overlapping portion.

Abstract: Systems and methods are utilized for performing geometric multiplexing in MEMS display systems that utilize RGB laser diodes and MEMS mirrors to compensate for angular separation between the RGB light that results from passing the RGB light emitted from the RGB laser diodes through a single collimating lens shared by the RGB laser diodes, as opposed to utilizing a separate collimating lens for each corresponding laser diode. Spatial offsets between the RGB light at the target display, resulting from the angular separation, are compensated for by applying temporal buffers to the pulsing of the RGB laser sources so that the RGB light is horizontally and vertically aligned at the appropriate pixels of the target display during scanning by the MEMS mirrors system.