The disclosed aliphatic thermoplastic polyurethane composition is well suited for use in thin, flexible light directing articles to impart flexibility, toughness, or protection to the light directing articles that contain optically active elements. The disclosed aliphatic thermoplastic polyurethanes have improved thermostability at higher temperatures. Specifically, the disclosed aliphatic thermoplastic polyurethanes have a cross-over temperature greater than 110° C. In one embodiment, the cross-over temperature is greater than 130° C. In one embodiment, the cross-over temperature is less than 170° C. and a Tg greater than 35° C. and less than 70° C.

A micromirror comprising a mirror pivotally attached to a mount by a first pivoting structure that permits pivotal movement of the mirror relative to the mount about a first axis. A first comb drive with a first portion fixed relative to the mirror and a second portion fixed relative to the mount, and the first comb drive are adapted to actuate the mirror about the first axis. A first support structure pivotally attached to the mount by a second pivoting structure that permits pivotal movement of the mount relative to the first support structure about a second axis, and the second axis is non-parallel to the first axis. A second comb drive with a first portion fixed relative to the mount and a second portion fixed relative to the first support structure, and the second comb drive is adapted to actuate the mount about the second axis.

A lidar system includes one or more light sources configured to generate a first beam of light and a second beam of light, a scanner configured to scan the first and second beams of light across a field of regard of the lidar system, and a receiver configured to detect the first beam of light and the second beam of light scattered by one or more remote targets. The scanner includes a rotatable polygon mirror that includes multiple reflective surfaces angularly offset from one another along a periphery of the polygon mirror, the reflective surfaces configured to reflect the first and second beams of light to produce a series of scan lines as the polygon mirror rotates. The scanner also includes a pivotable scan mirror configured to (i) reflect the first and second beams of light and (ii) pivot to distribute the scan lines across the field of regard.

A system includes a high energy laser (HEL) configured to transmit a HEL beam aimed at a first location on an airborne target. The system also includes a beacon illuminator laser (BIL) configured to transmit a BIL beam aimed at a second location on the target, wherein the second location is offset from the first location. The system also includes at least one fast steering mirror (FSM) configured to steer the BIL beam to be spatially and angularly offset from the HEL beam. The system also includes at least one Coudé path FSM configured to simultaneously receive both the HEL beam and the BIL beam and steer the HEL beam and the BIL beam to correct for atmospheric jitter of the HEL beam and the BIL beam while maintaining the offset of the BIL beam from the HEL beam.

An optical assembly of an imaging device includes an array of lens assemblies each having a double-folded optical axis, and an image sensor. Each of the lens assemblies each having the double-folded optical axis includes an input optical axis folding element, at least one lens having an optical power, and an output optical axis folding element. The input optical axis folding element of each of the lens assemblies having the double-folded optical axis is configured to change a field of view (FOV) of the input optical axis folding element by changing an optical axis folding angle of the input optical axis folding element about two axes.

A heliostat field layout for a concentrated solar power (CSP) plant includes a plurality of heliostats arranged adjacent each other (e.g., side-by-side) in a first arc spaced from a tower comprising a solar receiver. A second plurality of heliostats are arranged adjacent each other (e.g., side-by-side) in one or more additional arcs spaced from each other and spaced from the first arc, each additional arc spaced from a previous of the additional arcs by a radial distance that defines an aisle, the radial distance between a pair of adj acent arcs being equal to or greater than the radial distance between a previous pair of adjacent arcs in a direction away from the tower. The heliostats are arranged in the arcs in a non-staggered manner.

An imaging correction unit and an imaging module are provided. The imaging correction unit has an optical axis and includes four wedge optical elements with the same structure. The wedge optical elements are disposed sequentially on the optical axis. Each of the wedge optical elements has a minimum thickness dimension at a first edge and a maximum thickness dimension at a second edge. A connection line between the first edge and the second edge forms a symmetry axis of the each of the wedge optical elements. When a beam transmitted along the optical axis of the imaging correction unit passes sequentially through the wedge optical elements and is imaged at a center of an imaging surface, the symmetry axis of any one of the four wedge optical elements is at an angle of 90 degrees relative to the symmetrical axis of one of adjacent wedge optical elements.

A reading device includes an emission unit that emits light; a first reflecting unit having a first reflecting surface that reflects the light emitted by the emission unit toward a document; an optical path unit including a second reflecting unit having a second reflecting surface that reflects the light reflected by the first reflecting unit and specularly reflected by the document, the optical path unit defining an optical path that guides the light reflected by the second reflecting surface; an image sensor that generates an image represented by light guided by the optical path unit; and a support unit that supports the first reflecting unit and the second reflecting unit and fixes a relative position and a relative orientation between the first reflecting surface and the second reflecting surface.

A microelectromechanical systems (MEMS) scanning device comprising a torsional beam flexure that has a variable width in relation to a rotational axis for a scanning mirror. The geometric properties of the torsional beam vary along the rotational axis to increase a desired mode of mechanical strain at a location where a strain sensor is operating within the MEMS scanning device to generate a feedback signal. The torsional beam flexure mechanically suspends the scanning mirror from a frame structure. During operation of the MEMS scanning device, actuators induce torsional deformation into the torsional beam flexure to cause rotation of the scanning mirror about the rotational axis. The degree or amount of this torsional deformation is directly related to the angular position of the scanning mirror and, therefore, the desired mode of mechanical strain may be this torsional deformation strain component.

A method for displaying virtual content to a user, the method includes determining an accommodation of the user's eyes. The method also includes delivering, through a first waveguide of a stack of waveguides, light rays having a first wavefront curvature based at least in part on the determined accommodation, wherein the first wavefront curvature corresponds to a focal distance of the determined accommodation. The method further includes delivering, through a second waveguide of the stack of waveguides, light rays having a second wavefront curvature, the second wavefront curvature associated with a predetermined margin of the focal distance of the determined accommodation.