A time of flight based depth detection system is disclosed that includes a projector configured to sequentially emit multiple complementary illumination patterns. A sensor of the depth detection system is configured to capture the light from the illumination patterns reflecting off objects within the sensor's field of view. The data captured by the sensor can be used to filter out erroneous readings caused by light reflecting off multiple surfaces prior to returning to the sensor.

Techniques for designing diffractive optical elements (DOEs) such as diffusers and other optical beam shaping elements can include designing a DOE unit cell on a smaller area than the overall area of the DOE, and then distributing the unit cell across the entire surface for the DOE. Height translations are introduced for at least some of the unit cells distributed across the surface, where the height translations correspond to respective phase translations for the intended operational wavelength of the DOE. In some instances, phase wrapping is introduced to translate the height variations among the unit cells into unit cells having sub-unit structures whose heights fall within a range that corresponds to a specified phase range at the operational wavelength.

A planar illumination device of an embodiment includes a substrate, a first linear Fresnel lens, and a second linear Fresnel lens. The substrate includes a plurality of light sources disposed two-dimensionally in a grid pattern. The first linear Fresnel lens is disposed at an emission side of the plurality of light sources and formed with a groove constituting a concave-convex surface of the lens and extending in one direction. The second linear Fresnel lens is disposed at an emission side of the first linear Fresnel lens and formed with a groove constituting the concave-convex surface of the lens and extending in a direction orthogonal to the one direction.

According to the present disclosure, an optical signal emitted from a single molecule is received to measure a central location of the single molecule while changing a phase of a structured illumination having a periodic pattern to measure a phase of a pattern in which a fluorescence intensity is periodically changed in accordance with a distance between the pattern and the single molecule while displacing the periodic pattern by a specific interval to measure the central location of the single molecule, thereby improving an accuracy of the central location of the single molecule with low photons and as a result, the resolution of the image may be enhanced.

A structured light projection module and a depth camera are provided. The structured light projection module includes: a light source array including a plurality of sub-light sources arranged in a two-dimensional pattern and configured to transmit array beams corresponding to the two-dimensional pattern; a lens configured to receive and converge the array beams; and a diffractive optical element configured to receive the array beams that are emitted after being converged by the lens and project beams in a structured light speckle pattern. The structured light speckle pattern is formed through staggered superposition of at least two secondary structured light speckle patterns. Each secondary structured light speckle pattern is formed through a tiling arrangement of multiple sub-speckle patterns generated by a portion of the sub-light sources, and comprises speckles formed by diffracting an individual sub-light source via the diffractive optical element.

An optical device includes: a light source that emits laser light; an optical waveguide element positioned on the optical path of the laser light; a first member positioned on the optical path, and has a bottom surface that faces the optical waveguide element, and a side surface that is rotationally symmetric about the optical path; and a control circuit. The optical waveguide element includes: a first grating that includes a plurality of portions arranged in the radial direction and having mutually different refractive indices, and that causes a portion of the laser light that is incident to be propagated in the radial direction within the optical waveguide element; and a second grating that includes a plurality of portions arranged outside the first grating, arranged in the radial direction, and having mutually different refractive indices, and that causes light to be emitted from the optical waveguide element.

A laser projection module is provided. The laser projection module includes a substrate assembly, a lens barrel assembly, a light source, a diffractive optical element and a collimation element. The lens barrel assembly includes a lens barrel and a stop member connected to the lens barrel. The lens barrel is disposed on the substrate assembly and configured to define a receiving cavity together with the substrate assembly. The light source is disposed on the substrate assembly, accommodated in the receiving cavity, and configured to emit laser to the receiving cavity. The diffractive optical element and the collimation element are accommodated in the receiving cavity. The light source, the collimation element and the diffractive optical element are sequentially disposed in an optical path of the light source. The stop member is configured to prevent the diffractive optical element from moving in a light-emitting direction of the laser projection module.

A projector assembly includes three coaxially aligned lenses and an aperture stop. The three coaxially aligned lenses include a first lens and, in order of increasing distance therefrom and on a same side thereof, a second lens and a positive meniscus lens. The first lens is a positive lens. The second lens is a negative lens. The second lens is located between the aperture stop and the positive meniscus lens. The projector assembly is one-sided telecentric at a plane proximate the positive meniscus lens.

A quantitative phase microscopy (QPM) system and methods are provided for sample imaging and metrology in both transmissive and reflective modes. The QPM system includes a first illuminating beam propagating along a transmission-mode path and a second illuminating beam propagating along a reflection-mode path, a microscope objective lens disposed in the reflection-mode path, and a common-path interferometer comprising a diffraction grating, a Fourier lens, a pinhole, and a 2f system lens to collimate the reference beam and the imaging beam such that the collimated reference beam and imaging beam interfere with each other to form an interferogram at a final image plane.

An example optical assembly includes a display, a light source for illuminating the display, and a first diffraction type polarizing beam splitter (DT-PBS) configured to direct light from a first light director, wherein the first DT-PBS is polarization sensitive and configured to direct, based on polarization, a first portion of light towards the display.