Window glass having sun-facing daylight redirecting optical structures with an embedded surface diffuser patterned on them. The optical structures are generally linear and formed from a repeating unit cell. Each unit cell has a base, two or more peaks opposite the base, and at least one curved side between the base and the peaks. The other sides between the base and the peaks can be substantially straight, curved, or a series of facets approximating a curve.

An improved mount for, and method of mounting an, optical structure is provided. The mount has an optical structure comprising at least one mirror panel, the mirror panel comprising a reflective surface and a back surface substantially opposite the reflective surface, a protruding member extending from the back surface of the optical structure, the protruding member having a shape and the shape having an outside surface there-around, a base comprising a mounting element and an upper element extending from the mounting element, the upper element having a cavity for secured receipt therein of at least a portion of the protruding member, wherein the receiving cavity of the upper element has a shape identical to that of the shape of the protruding member, but where the shape of the protruding member is ten thousandths ( 1/10,000) of an inch smaller than the shape of the receiving cavity so that the outside surface of the protruding member is ten thousandths ( 1/10,000) of an inch away from the corresponding parts of the receiving cavity when the protruding member is secured within the cavity.

An improved mount for, and method of mounting an, optical structure is provided. The mount has an optical structure comprising at least one mirror panel, the mirror panel comprising a reflective surface and a back surface substantially opposite the reflective surface, a protruding member extending from the back surface of the optical structure, the protruding member having a shape and the shape having an outside surface there-around, a base comprising a mounting element and an upper element extending from the mounting element, the upper element having a cavity for secured receipt therein of at least a portion of the protruding member, wherein the receiving cavity of the upper element has a shape identical to that of the shape of the protruding member, but where the shape of the protruding member is ten thousandths ( 1/10,000) of an inch smaller than the shape of the receiving cavity so that the outside surface of the protruding member is ten thousandths ( 1/10,000) of an inch away from the corresponding parts of the receiving cavity when the protruding member is secured within the cavity.

An improved mount for, and method of mounting, an optical structure having a grooved/relieved protruding member is provided. The mount may have the grooved/relieved protruding member extending from a surface of the optical structure, a base element for mounting the mount to another structure and an upper element extending from the base element having a first opening extending therethrough for receipt therein of at least a portion of the grooved/relieved member. The first opening defines first and second arms, each of the arms comprising a head portion and each of the head portions ending at an end. A second opening in the upper element extends through one of the head portions and the end thereof in a direction toward the other head portion, while a third opening exists in the upper element through the end of the other head portion in an orientation substantially opposite to and in communication with the second opening so that a tightening mechanism may be received through the second opening and the third opening. Tightening of the tightening mechanism into the third opening causes the ends of the head portions to draw toward each other so that the first opening of the upper element tightens around the at least a portion of the grooved/relieved protruding member.

An improved mount for, and method of mounting, an optical structure having a grooved/relieved protruding member is provided. The mount may have the grooved/relieved protruding member extending from a surface of the optical structure, a base element for mounting the mount to another structure and an upper element extending from the base element having a first opening extending therethrough for receipt therein of at least a portion of the grooved/relieved member. The first opening defines first and second arms, each of the arms comprising a head portion and each of the head portions ending at an end. A second opening in the upper element extends through one of the head portions and the end thereof in a direction toward the other head portion, while a third opening exists in the upper element through the end of the other head portion in an orientation substantially opposite to and in communication with the second opening so that a tightening mechanism may be received through the second opening and the third opening. Tightening of the tightening mechanism into the third opening causes the ends of the head portions to draw toward each other so that the first opening of the upper element tightens around the at least a portion of the grooved/relieved protruding member.

This disclosure generally relates to retroreflective articles and methods of making such articles.

An optical system configured as part of optical metrology unit used to assess the operational status of a workpiece and, in a specific case, configured as an encoder head of a lithographic exposure tool. The optical system is devoid of a stand-alone optical corner-cubes and includes, instead, a single, imperfect or frustrated cuboid of optically-isotropic material that, in operation with the diffraction grating of the workpiece, simultaneously forms four interferometric signals for measuring x-, y, and z-positions of the workpiece grating relative to the optical system. Proposed system and method solve problems of (i) structural complexity of a conventional metrology unit for use in an exposure tool, (ii) burdensome alignment of the multitude of optical prisms in the process of forming such metrology unit, and (iii) cyclic non-linear errors associated with measurements involving conventional corner-cubes-based metrology units.

An optical system configured as part of optical metrology unit used to assess the operational status of a workpiece and, in a specific case, configured as an encoder head of a lithographic exposure tool. The optical system is devoid of a stand-alone optical corner-cubes and includes, instead, a single, imperfect or frustrated cuboid of optically-isotropic material that, in operation with the diffraction grating of the workpiece, simultaneously forms four interferometric signals for measuring x-, y, and z-positions of the workpiece grating relative to the optical system. Proposed system and method solve problems of (i) structural complexity of a conventional metrology unit for use in an exposure tool, (ii) burdensome alignment of the multitude of optical prisms in the process of forming such metrology unit, and (iii) cyclic non-linear errors associated with measurements involving conventional corner-cubes-based metrology units.

A method for aligning a first optical transceiver includes steps of splitting, directing, recording, and actuating. The splitting step includes splitting a light beam into a) a reference beam that propagates along a common optical path within the first optical transceiver and b) a transmit beam that that propagates away from the first optical transceiver and toward a second optical transceiver. The directing step includes directing, with a beam director, a receive beam from the second optical transceiver onto the common optical path. The recording step includes recording, with a tracking focal-plane array (FPA) that intersects the common optical path, a reference-position of the reference beam and an initial-received-position of the receive beam on the tracking FPA. The actuating step includes actuating the beam director based upon the initial-received-position to achieve a subsequent position of the receive beam on the tracking FPA.

A method for aligning a first optical transceiver includes steps of splitting, directing, recording, and actuating. The splitting step includes splitting a light beam into a) a reference beam that propagates along a common optical path within the first optical transceiver and b) a transmit beam that that propagates away from the first optical transceiver and toward a second optical transceiver. The directing step includes directing, with a beam director, a receive beam from the second optical transceiver onto the common optical path. The recording step includes recording, with a tracking focal-plane array (FPA) that intersects the common optical path, a reference-position of the reference beam and an initial-received-position of the receive beam on the tracking FPA. The actuating step includes actuating the beam director based upon the initial-received-position to achieve a subsequent position of the receive beam on the tracking FPA.