Disclosed is a method and associated apparatus for measuring a characteristic of interest relating to a structure on a substrate. The method comprises calculating a value for the characteristic of interest directly from the effect of the characteristic of interest on at least the phase of illuminating radiation when scattered by the structure, subsequent to illuminating said structure with said illuminating radiation.

A novel class of imaging systems that combines diffractive optics with 1D line sensing is disclosed. When light passes through a diffraction grating or prism, it disperses as a function of wavelength. This property is exploited to recover 2D and 3D positions from line images. A detailed image formation model and a learning-based algorithm for 2D position estimation are disclosed. The disclosure includes several extensions of the imaging system to improve the accuracy of the 2D position estimates and to expand the effective field-of-view. The invention is useful for fast passive imaging of sparse light sources, such as streetlamps, headlights at night and LED-based motion capture, and structured light 3D scanning with line illumination and line sensing.

The light extraction device, the detection equipment and the operation method thereof are provided. The light extraction device includes at least one light splitting unit, each of the at least one light splitting unit includes a color separation grating, configured to separate light incident on the color separation grating into a plurality of light beams that are collimated and propagated in different directions and have different colors; a first lens, disposed corresponding to the color separation grating and configured to converge the plurality of light beams; and a first pinhole, located on a side of the first lens away from the color separation grating and correspondingly arranged with the first lens. The first lens is configured to converge a light beam having a preset color in the plurality of light beams to the first pinhole and allow the light beam having the preset color to exit.

A viewing angle light control film and a display having the same are discussed. The viewing angle light control film according to the present disclosure can include a base film, a first optical layer disposed on the base film, a second optical layer contacting the first optical layer, and a light scattering pattern disposed at an interface between the first optical layer and the second optical layer.

A system for electromagnetic communication with a vortex beam concurrently conveys multiple topological charges of orbital angular momentum. The system includes a source, at least one vortex-sensing diffraction grating, and an array of photodetectors. The source generates the vortex beam concurrently conveying a respective number of selected topological charges during each of the time intervals. The selected topological charges for each time interval are selected from a set of available topological charges. The selected topological charges for each time interval encode a symbol of data. The vortex-sensing diffraction grating combines a vortex phase pattern and a linear phase pattern. The vortex sensing diffraction grating produces a diffraction pattern from diffracting the vortex beam received from the source. The array of photodetectors detects portions of the diffraction pattern and from the detected portions recovers the selected topological charges encoding the symbol of each time interval.

An optical computing device includes: one or more light-diffraction elements each of which includes microcells, wherein each of the microcells has an individually set thickness or refractive index; and an optical signal input section that simultaneously inputs an optical signal and a delayed optical signal obtained by delaying the optical signal to the one or more light-diffraction elements.

A two-dimensional magneto-optical trap (2D GMOT) that is configured to produce a cold-atom beam exiting the 2D GMOT is disclosed. In embodiments, the 2D GMOT is configured to feed a three-dimensional GMOT with the cold atom beam. In embodiments, the 2D GMOT includes an input light beam having its direction along a first axis, its width along a second axis, normal to the first axis, and a substantially flat input light beam intensity profile. 2D GMOT may further includes a quadrupole magnetic field with its magnitude being zero along a third axis that is centered at the center of the input light beam's width. The 2D GMOT may also include a diffraction-grating surface positioned normal to the first axis, composed of closely adjacent parallel grooves spread across the width and run parallel to the third axis.

An illumination optical apparatus illuminates a pattern on a mask with illumination light. The illumination optical apparatus includes an optical integrator arranged in an optical path of the illumination light, and a polarization member made of optical material with optical rotatory power, which is arranged in the optical path on an incidence side of the optical integrator, and which changes a polarization state of the illumination light. The illumination light from the polarization member is irradiated onto the pattern through a pupil plane of the illumination optical apparatus.

A micro-electromechanical structure for modulating light beams includes multiple asymmetric deformable diffractive elements, each having an L-shaped cross section, split pedestal and flexible reflective member. The reflective member has an elongated shape, and a supported part and unsupported part. The split pedestal extends along the long dimension of the supported part of the reflective member and is anchored to a substrate which supports one or more electrodes or serves as an electrode. The diffractive element is movable between a non-energized position wherein the diffractive element acts to reflect a beam of light as a planar mirror, to an energized position wherein upon application of an electrostatic force, the diffractive element flexes independently about an axis parallel to the long dimension of each reflective member to vary a curvature of the reflective member to form a blazed grating.

The disclosed structured light projector may include (1) a light source having a light-emitting side that emits light, (2) a solid optical spacer element having a first side securely coupled to the light-emitting side of the light source, and (3) a diffractive optical element (DOE) stack including one or more DOEs, where the DOE stack includes (a) a light-receiving side securely coupled to a second side of the solid optical spacer element opposite the first side, and (b) a light-emitting side opposite the light-receiving side that emits structured light in response to the light received from the light-emitting side of the light source via the solid optical spacer element. Various other devices and methods are also disclosed.