A waveguide apparatus includes a planar waveguide and at least one optical diffraction element (DOE) that provides a plurality of optical paths between an exterior and interior of the planar waveguide. A phase profile of the DOE may combine a linear diffraction grating with a circular lens, to shape a wave front and produce beams with desired focus. Waveguide apparati may be assembled to create multiple focal planes. The DOE may have a low diffraction efficiency, and planar waveguides may be transparent when viewed normally, allowing passage of light from an ambient environment (e.g., real world) useful in AR systems. Light may be returned for temporally sequentially passes through the planar waveguide. The DOE(s) may be fixed or may have dynamically adjustable characteristics. An optical coupler system may couple images to the waveguide apparatus from a projector, for instance a biaxially scanning cantilevered optical fiber tip.

Optical scanner and electrophotographic image forming device are provided. The optical scanner includes a light source; and a first optical unit, a deflection apparatus, and an f-θ lens, which are sequentially arranged along a primary optical axis direction of a light beam emitted from the light source. The light beam emitted from the light source is focused onto a scanning target surface after sequentially passing through the first optical unit, the deflection apparatus, and the f-θ lens. Optical scanning directions of the light beam emitted from the light source include a primary scanning direction and a secondary scanning direction which are perpendicular to each other, and along the primary scanning direction, the f-θ lens satisfies following expressions: SAG1>0, SAG2>0, and 0<(SAG1+SAG2)/d<0.8.

An apparatus for intraoral scanning comprises an elongate handheld wand comprising a probe at a distal end, one or more light projectors, and two or more cameras. Each light projector comprises at least one light source configured to generate light and a pattern generating optical element configured to generate a pattern of light when the light is transmitted through the pattern generating optical element. Each camera comprises a camera sensor and one or more lenses and is configured to capture a plurality of images that depict at least a portion of the projected pattern of light on an intraoral surface, wherein each camera is configured to focus at an object focal plane that is located between about 1 mm and about 30 mm from a lens of the one or more lenses that is farthest from the camera sensor.

A diffractive optical element includes a substrate including a plurality of unit cells arrayed across the substrate. Each of the unit cells includes M phase elements and each of the M phase elements is characterized by one of a set of N phase values. Each of the set of N phase values is equal to an incremental phase value times an index m, wherein M>1 and m=1 . . . N.

For example, a flowcell includes: a nanowell layer having a first set of nanowells and a second set of nanowells to receive a sample; a first linear waveguide associated with the first set of nanowells, and a second linear waveguide associated with the second set of nanowells; and a first grating for the first linear waveguide, and a second grating for the second linear waveguide, the first and second gratings providing differential coupling of first light and second light.

A transparent wearable data display having a source of collimated light, a deflector for deflecting the collimated light into a scanned beam, and a first of switchable grating elements sandwiched between first and second parallel transparent substrates, which together functioning as a first light guide. A first coupling is provided for directing the scanned beam into a first total internal reflection (TIR) light path of the first light guide along the first array column. The grating elements having diffracting and non-diffracting states, in their diffracting state deflecting light out of said light guide. The grating elements arc switchable into their diffracting states one group of elements at a time.

An apparatus for intraoral scanning comprises an elongate handheld wand comprising a probe at a distal end, one or more light projectors, and two or more cameras. Each light projector comprises at least one light source configured to generate light and a pattern generating optical element configured to generate a pattern of light when the light is transmitted through the pattern generating optical element. Each camera comprises a camera sensor and one or more lenses and is configured to capture a plurality of images that depict at least a portion of the projected pattern of light on an intraoral surface, wherein each camera is configured to focus at an object focal plane that is located between about 1 mm and about 30 mm from a lens of the one or more lenses that is farthest from the camera sensor.

A virtual image display apparatus includes an imaging light emitting unit configured to emit imaging light, and a light-guiding unit configured to guide the imaging light. The light-guiding unit is configured by arranging a first, a second, a third, and a fourth optical system in the stated order in a travel direction of the imaging light. The first optical system forms a first intermediate image of the imaging light. The second optical system includes a first diffraction element forming a pupil between the second and the fourth optical system. The third optical system forms a second intermediate image. The fourth optical system includes a second diffraction element forming an exit pupil by diffracting the imaging light. At the exit pupil, luminance of pixels at a central position of the imaging light and luminance of pixels at end positions of the imaging light differ.

A light pattern generation device is provided with a laser light source to emit laser light, a light scanner to deflect the laser light emitted from the laser light source, and a diffractive optical element unit including a plurality of diffractive optical element components each of which modulates at least one of phase distribution or intensity distribution of the laser light deflected by the light scanner so that the laser light that passes therethrough forms a predetermined light pattern on an image plane. The light scanner can change a deflection direction in which the laser light emitted from the laser light source is deflected so that the laser light emitted from the laser light source is deflected toward a predetermined diffractive optical element component out of the plurality of diffractive optical element components.

For example, a flowcell includes: a nanowell layer having a first set of nanowells and a second set of nanowells to receive a sample; a first linear waveguide associated with the first set of nanowells, and a second linear waveguide associated with the second set of nanowells; and a first grating for the first linear waveguide, and a second grating for the second linear waveguide, the first and second gratings providing differential coupling of first light and second light.