Abstract: A light pipe includes at least two optical structures having different refractive indices. An interface between the two optical structures is oblique to a longitudinal axis of the light pipe such that an output ray from an output surface at a distal end of the light pipe is non-parallel to an input ray that is parallel to the longitudinal axis at an input surface at a proximal end of the light pipe. Light refracts inside the light pipe between the (at least) two optical structures altering the direction of an optical path of the light through the light pipe, thereby allowing higher degrees of freedom for the selection of the angle of deviation (folding angle) of the light pipe. By optimizing various parameters of the light pipe, a desired output optical axis angle (i.e., folding angle) can be achieved that suits the desired optical engine envelope.

Abstract: An optical system including a light-guide optical element (LOE) with first and second sets (204, 206) of mutually-parallel, partially-reflecting surfaces at different orientations. Both sets of partially-reflecting surfaces are located between parallel major external surfaces. A third set of at least partially-reflecting surfaces (202), deployed at the coupling-in region, receive image illumination injected from a projector (2) with an optical aperture having a first in-plane width and direct the image illumination via reflection of at least part of the image illumination at the third set of at least partially-reflective facets towards the first set of partially-reflective facets with an effective optical aperture having a second width larger than the first width.

Abstract: An optical system including a light-guide optical element (LOE) with first and second sets (204, 206) of mutually-parallel, partially-reflecting surfaces at different orientations. Both sets of partially-reflecting surfaces are located between parallel major external surfaces. A third set of at least partially-reflecting surfaces (202), deployed at the coupling-in region, receive image illumination injected from a projector (2) with an optical aperture having a first in-plane width and direct the image illumination via reflection of at least part of the image illumination at the third set of at least partially-reflective facets towards the first set of partially-reflective facets with an effective optical aperture having a second width larger than the first width.

Abstract: Disclosed herein is an optical assembly for generating a color image using white light as source. The optical assembly includes a broadband white light source array, a color filter assembly configured to allow selectively filtering therethrough light in each of three additive primary colors, and a control unit. The control unit is configured to actuate light sources in the light source array according to three intensity maps. Each of the intensity maps corresponds to one of the three additive primary colors. The control unit is further configured to synchronize operations of the light source array and the color filter arrangement such that, when light sources in the light source array are actuated according to one of the three intensity maps, the color filter arrangement filters therethrough light at the additive primary color to which the intensity map corresponds.

Abstract: An optical system including a light-guide optical element (LOE) with first and second sets (204, 206) of mutually-parallel, partially-reflecting surfaces at different orientations. Both sets of partially-reflecting surfaces are located between parallel major external surfaces. A third set of at least partially-reflecting surfaces (202), deployed at the coupling-in region, receive image illumination injected from a projector (2) with an optical aperture having a first in-plane width and direct the image illumination via reflection of at least part of the image illumination at the third set of at least partially-reflective facets towards the first set of partially-reflective facets with an effective optical aperture having a second width larger than the first width.

Abstract: Optical sample characterization facilitates measurement and testing such as transmittance or reflectance at any discrete angle in a full range of angles of light propagation through a coated glass plate having a higher than air index of refraction. A rotatable assembly includes a cylinder having a hollow, and a receptacle including the hollow. The receptacle also contains a fluid having a refractive index matching the refractive index of the cylinder and coated plate. An optical light beam is input normal to the surface of the cylinder, travels through the cylinder, then via the index matching fluid through the coating, the coated glass plate, the fluid, the other side of the cylinder, and is collected for analysis. Due at least in part to the index matching fluid surrounding the coated plate, the plate can be rotated through a full range of angles (±90°, etc.) for full range testing of the coating.

Abstract: A vehicular head-up display (HUD) for displaying an image to a user of a vehicle having a windshield (15) includes an image projector (14) outputting a collimated image and an optical aperture expander. The optical aperture expander includes a light-guide optical element (LOE) (10) having two major external surfaces (30a, 30b). The image projector (14) injects the collimated image so as to propagate within the LOE by internal reflection at the major external surfaces. The LOE also has a set of parallel partially-reflecting internal surfaces (12) which progressively couple out the image illumination from the LOE. The optical aperture expander is deployed such that the image illumination coupled-out of the LOE (12) follows a light path including a reflection from a surface associated with the windshield (15) of the vehicle so as to be visible to the user while the user looks at a scene beyond the windshield.

Abstract: Optical sample characterization facilitates measurement and testing at any angle in a full range of angles of light propagation through an optical sample, such as a coated glass plate, having a higher than air index of refraction. A rotatable assembly includes a cylinder having a hollow, and a receptacle including the hollow. The receptacle also contains a fluid with a known refractive index. An optical light beam is input normal to the surface of the cylinder, travels through the cylinder, then via the fluid, to the optical sample, where light beam is transmitted and/or reflected, then exits the cylinder and is collected for analysis. Due at least in part to the fluid surrounding the optical sample, the optical sample can be rotated through a full range of angles (±90°, etc.) for full range testing of the optical sample.

Abstract: An optical system including a light-guide optical element (LOE) with first and second sets (204, 206) of mutually-parallel, partially-reflecting surfaces at different orientations. Both sets of partially-reflecting surfaces are located between parallel major external surfaces. A third set of at least partially-reflecting surfaces (202), deployed at the coupling-in region, receive image illumination injected from a projector (2) with an optical aperture having a first in-plane width and direct the image illumination via reflection of at least part of the image illumination at the third set of at least partially-reflective facets towards the first set of partially-reflective facets with an effective optical aperture having a second width larger than the first width.

Abstract: A light pipe includes at least two optical structures having different refractive indices. An interface between the two optical structures is oblique to a longitudinal axis of the light pipe such that an output ray from an output surface at a distal end of the light pipe is non-parallel to an input ray that is parallel to the longitudinal axis at an input surface at a proximal end of the light pipe. Light refracts inside the light pipe between the (at least) two optical structures altering the direction of an optical path of the light through the light pipe, thereby allowing higher degrees of freedom for the selection of the angle of deviation (folding angle) of the light pipe. By optimizing various parameters of the light pipe, a desired output optical axis angle (i.e., folding angle) can be achieved that suits the desired optical engine envelope.

Abstract: A system and method for measuring refractive index inhomogeneity between plates of a Lightguide Optical Element (LOE) uses an innovative measuring technique based on a shearing interferometric technique conventionally used to observe interference and test the collimation of light beams. Another feature of the current implementation is an innovative method for analyzing the characteristics of the generated interferogram to characterize discrepancies between adjacent plates in an LOE.

Abstract: An optical system including a light-guide optical element (LOE) with first and second sets (204, 206) of mutually-parallel, partially-reflecting surfaces at different orientations. Both sets of partially-reflecting surfaces are located between parallel major external surfaces. A third set of at least partially-reflecting surfaces (202), deployed at the coupling-in region, receive image illumination injected from a projector (2) with an optical aperture having a first in-plane width and direct the image illumination via reflection of at least part of the image illumination at the third set of at least partially-reflective facets towards the first set of partially-reflective facets with an effective optical aperture having a second width larger than the first width.

Abstract: Optical sample characterization facilitates measurement and testing such as transmittance or reflectance at any discrete angle in a full range of angles of light propagation through a coated glass plate having a higher than air index of refraction. A rotatable assembly includes a cylinder having a hollow, and a receptacle including the hollow. The receptacle also contains a fluid having a refractive index matching the refractive index of the cylinder and coated plate. An optical light beam is input normal to the surface of the cylinder, travels through the cylinder, then via the index matching fluid through the coating, the coated glass plate, the fluid, the other side of the cylinder, and is collected for analysis. Due at least in part to the index matching fluid surrounding the coated plate, the plate can be rotated through a full range of angles (±90°, etc.) for full range testing of the coating.

Abstract: At various positions in an eye motion box (EMB) an output image from an optical device can be captured and analyzed for detection and evaluation of image propagation via the optical device. Optical testing along a specific axis can evaluate optical engine transfer function uniformity across facet's active area, detect the existence and degree of “smearing” of a projected image from an optical device, and detect the existence and degree of a “white stripes” (WS) phenomenon related to scattering and diffraction in the wedge-to-LOE interface. A variety of metrics can be derived for quality control and feedback into the production system, and for disposition of the optical devices.

Abstract: Optical sample characterization facilitates measurement and testing such as transmittance or reflectance at any discrete angle in a full range of angles of light propagation through a coated glass plate having a higher than air index of refraction. A rotatable assembly includes a cylinder having a hollow, and a receptacle including the hollow. The receptacle also contains a fluid having a refractive index matching the refractive index of the cylinder and coated plate. An optical light beam is input normal to the surface of the cylinder, travels through the cylinder, then via the index matching fluid through the coating, the coated glass plate, the fluid, the other side of the cylinder, and is collected for analysis. Due at least in part to the index matching fluid surrounding the coated plate, the plate can be rotated through a full range of angles (±90°, etc.) for full range testing of the coating.

Abstract: A near-eye display includes a light-guide optical element (LOE) (10) having first and second major external surfaces (11A, 11B) that are planar and mutually parallel. An image projector (2) introduces into the LOE illumination corresponding to an image so that the illumination propagates within said LOE by internal reflection at the major external surfaces. A coupling-out arrangement couples the illumination out of the LOE towards the eye of the observer. The coupling-out arrangement may be a set of mutually-parallel, partially-reflective surfaces (12A) deployed at an oblique angle within the LOE. Various arrangements for suppressing reflections of ambient light sources include obstructing baffles oriented so as to avoid reduction of peripheral field of view, various non-reflective coatings and various deployments of polarization filters.

Abstract: An optical aperture expansion arrangement particularly useful for near-eye displays employs a waveguide (30, 140, 145) with wedge configurations (25, 26) to generate two modes of propagation of image illumination along the waveguide, and to couple out both modes from the waveguide. Various embodiments employ rectangular waveguides within which the image illumination propagates by four-fold internal reflection. In some cases, the wedge configurations are combined with an array of partially-reflective internal surfaces (45, 150) to achieve two-dimensional aperture expansion.

Abstract: An optical system including a light-guide optical element (LOE) with first and second sets (204, 206) of mutually-parallel, partially-reflecting surfaces at different orientations. Both sets of partially-reflecting surfaces are located between parallel major external surfaces. A third set of at least partially-reflecting surfaces (202), deployed at the coupling-in region, receive image illumination injected from a projector (2) with an optical aperture having a first in-plane width and direct the image illumination via reflection of at least part of the image illumination at the third set of at least partially-reflective facets towards the first set of partially-reflective facets with an effective optical aperture having a second width larger than the first width.

Abstract: A light-guide optical element (LOE) for simultaneous viewing, of a real scene and of a projected image introduced into the LOE, having a transparent block along which light conveying a projected image propagates by internal reflection, and a plurality of internal partially reflecting surfaces obliquely oriented and configured so as to couple-out a part of said light, wherein the reflectance of each of the partially reflecting surfaces is such that the total power of the light that is coupled out is less than one third of the total power of the light that is introduced into the LOE. In some embodiments, the light of the projected image is polarized and the reflectance of the partially reflecting surfaces for light polarized in an orthogonal orientation is substantially reduced. In some embodiments, the reflectance of the partially reflecting surfaces for light not reaching the viewer is substantially reduced.

Abstract: A system and method for measuring refractive index inhomogeneity between plates of a Lightguide Optical Element (LOE) uses an innovative measuring technique based on a shearing interferometric technique conventionally used to observe interference and test the collimation of light beams. Another feature of the current implementation is an innovative method for analyzing the characteristics of the generated interferogram to characterize discrepancies between adjacent plates in an LOE.