Systems, devices, and methods for providing optical engines and laser projectors that are well-suited for use in wearable heads-up displays (WHUDs) are described. The optical engines of the present disclosure may integrate a plurality of laser diodes (e.g., 3 laser diodes, 4 laser diodes) within a single, hermetically or partially hermetically sealed, encapsulated package. Wavelength stabilization for the laser diodes is achieved by controlling the temperature of the lasers to always be in a particular range of operating specifications which provides wavelength stabilization that meets particular performance criteria. The lasers themselves may be used for temperature control by selectively switching them on to maintain their temperature within a specified range. Alternatively, compact resistive heaters may be positioned proximate the laser diodes to control the temperature of the laser diodes during operation. WHUDs that employ such optical engines and laser projectors are also described. Additionally, optical systems for collimating and shifting light beams are described.

The image display device (100) provides images perceivable from the area of the eye box (E), and includes a light source unit (110), a screen (140), a scanning unit (130) and an optical system (155). The screen (140) has a single micro lens array (1) on which multiple micro lenses (3) are arranged. The scanning unit (130) includes a mirror (130a) to reflect beams emitted from the light source unit (110), and swings the mirror (130a) around a pivot center (130c) to scan the beams thereover, thereby generating images. The optical system (155) brings the images formed on the screen (140) to the eye box (E). An angle (θ.sub.out) formed between a zero-order diffracted beam and a first-order diffracted beam, which are among a luminous flux of beams diffracted by the screen (140) and pass through the center of the eye box (E), is smaller than a minimum visual angle (V.sub.min).

The general field of the invention is that of monochromatic stereoscopic image projectors including two light sources that illuminate two imagers, the radiation of the two light sources having a spectral distribution centred on a central wavelength, the first imager and the second imager being connected to a generator of stereoscopic image pairs. The image projector includes a dichroic separating filter that transmits the portion of the spectrum below the central wavelength and that reflects the portion of the spectrum above this central wavelength. The first light source and the second light source are arranged symmetrically on either side of the dichroic separating filter. The image projector operates cyclically, each cycle including two alternations. Each alternation consists in changing the emission source and in switching to the two displays the left and right images emitted by the generator of image pairs.

A wearable display system includes one or more emissive micro-displays, e.g., micro-LED displays. The micro-displays may be monochrome micro-displays or full-color micro-displays. The micro-displays may include arrays of light emitters. Light collimators may be utilized to narrow the angular emission profile of light emitted by the light emitters. Where a plurality of emissive micro-displays is utilized, the micro-displays may be positioned at different sides of an optical combiner, e.g., an X-cube prism which receives light rays from different micro-displays and outputs the light rays from the same face of the cube. The optical combiner directs the light to projection optics, which outputs the light to an eyepiece that relays the light to a user's eye. The eyepiece may output the light to the user's eye with different amounts of wavefront divergence, to place virtual content on different depth planes.

In some embodiments, a display system is provided. The display system comprises a plurality of light pipes and a plurality of light sources configured to emit light into the light pipes. The display system also comprises a spatial light modulator configured to modulate light received from the light pipes to form images. The display system may also comprise one or more waveguides configured to receive modulated light from the spatial light modulator and to relay that light to a viewer.

An imaging system includes a light source configured to generate a light beam. The system also includes first and second light guiding optical elements having respective first and second entry portions, and configured to propagate at least respective first and second portions of the light beam by total internal reflection. The system further includes a light distributor having a light distributor entry portion, a first exit portion, and a second exit portion. The light distributor is configured to direct the first and second portions of the light beam toward the first and second entry portions, respectively. The light distributor entry portion and the first exit portion are aligned along a first axis. The light distributor entry portion and the second exit portion are aligned along a second axis different from the first axis.

An artifact mitigation system includes a projector assembly and a set of imaging optics optically coupled to the projector assembly. The artifact mitigation system also includes an eyepiece optically coupled to the set of imaging optics. The eyepiece includes a diffractive incoupling interface. The artifact mitigation system further includes an artifact prevention element disposed between the set of imaging optics and the eyepiece. The artifact prevention element includes a linear polarizer, a first quarter waveplate disposed adjacent the linear polarizer, and a color select component disposed adjacent the first quarter waveplate.

A waveguide display includes a source assembly, an output waveguide, and a controller. The source assembly includes a light source and an optics system. The light source includes source elements arranged in a 1D or 2D array that emit image light. The optics system includes a scanning mirror assembly that scans the image light to particular locations based on scanning instructions. The output waveguide receives the scanned image light from the scanning mirror assembly and outputs an expanded image light. In some embodiments, the waveguide display includes a source waveguide and the 1D array of source elements. The source waveguide receives a conditioned image light from the source assembly. The controller generates the scanning instructions and provides the scanning instructions to the scanning mirror assembly. In some embodiments, the controller provides the scanning instructions to an actuator assembly of the source waveguide.

A light guide includes a first and second transparent monolithic optical parts (TMOP). The first TMOP has a first surface having two sets with one flat surface followed by one prism array. Each flat surface has a partially-reflective coating, and the first TMOP has a flat opposite second surface. Each prism array has two prisms having a first and a second surfaces which are oblique to each other and to the first TMOP's opposite second surface. The prism arrays first surfaces have a partially-reflective coating. The second TMOP has a first surface with a geometrically complementary shape relative to the shape of the first TMOP's first surface, and has a flat opposite second surface. The first and second TMOPs are assembled together using an optically transparent adhesive material, such that the second surfaces of the first and second TMOP of the light guide assembly are parallel to each other.

A light-emitting device includes: a first light-emitting element including a first light-emission surface through which first light is emitted along a first optical axis; a second light-emitting element disposed apart from the first light-emitting element in a first direction that is perpendicular to the first optical axis, the second light-emitting element including a second light-emission surface through which second light is emitted along a second optical axis that is inclined with respect to the first optical axis in a second direction opposite to the first direction; and a third light-emitting element disposed apart from the first light-emitting element in the second direction, wherein the third light-emitting element includes a third light-emission surface through which third light is emitted along a third optical axis that is inclined with respect to the first optical axis in the first direction.