Methods, devices and systems describe compact and simple deflectometry configurations that can measure complex shapes of freeform surfaces. One deflectometry system includes a first panel and a second panel positioned at an offset position from each other to provide illumination for an object. The second panel, positioned closer to the object, is operable as a substantially transparent panel, and as a pixelated panel to provide structured light patterns. The system also includes two or more cameras positioned on the second panel an is operable in a first mode where the first panel provides a first structured illumination and the second panel is configured as a substantially transparent panel that allows the first structured illumination from the first panel to transmit toward the object. The system is also operable in a second mode where the second panel is configured to provide a second structured illumination for illuminating the object.

A device (20) for detecting a temperature on a surface (15) of an optical element (14) for semiconductor lithography. The device includes an optical element (14) having a face (16) irradiated with electromagnetic radiation (7, 8, 43), a temperature recording device (21), and a temperature controlled element (22) configured to be temperature-controlled and arranged so that the predominant proportion of the intensity of the thermal radiation (25.2) detected by the temperature recording device and reflected by reflection at the surface of the optical element is emitted by the temperature-controlled element.

Also disclosed are an installation (1) for producing a surface (15) of an optical element (14) for semiconductor lithography and a method for producing a surface (15) of an optical element (14) of a projection exposure apparatus (30), wherein the surface is temperature-controlled and the surface temperature is detected during the temperature control.

A prism constant can be obtained more efficiently, using a laser positioning device including an image data obtaining portion obtaining an image data which is obtained by photographing a reflection prism device, a data storing portion storing a relationship of a prism constant of the reflection prism device and the image data, and a prism constant obtaining portion obtaining the prism constant of the reflection prism device based on the relationship.

A measuring device (10) for the interferometric shape measurement of a surface (12) of a test object (14-1; 14-2)includes (i) a diffractive optical element (26-1; 26-2) that generates a test wave (28) from incoming measurement radiation (18), wherein the diffractive optical element radiates the test wave onto the surface of the test object, (ii) a deflection element (22) that is disposed upstream of the diffractive optical element in the beam path of the measurement radiation, and (iii) a holding device (24, 124) that holds the deflection element and that changes a position of the deflection element (22) through a combination of a tilting movement and a translation movement.

A measurement apparatus for interferometric shape measurement of a test object surface. A test optical unit produces from measurement radiation a test wave for irradiating the surface. A reference element with an optically effective surface interacts with a reference wave also produced from the measurement radiation. An interferogram is produced by superimposing the test wave after interaction with the test object's surface. A holding device holds the reference element and moves the reference element relative to the reference wave in at least two rigid body degrees of freedom so that a peripheral point of the reference element's optically effective surface shifts by at least 0.1% of a diameter of the optically effective surface. The at least two degrees of freedom include a translational degree, directed transversely to a propagation direction of the reference wave and a rotational degree, whose rotational axis aligns substantially parallel to the reference wave's propagation direction.

The invention discloses a toric mirror surface shape measurement method. The measurement method is as follows: first, according to the parameter information of the toric mirror to be measured, using three-dimensional modeling software, establish a CAD model of the toric mirror to be measured and then import the CAD model into the three-coordinate machine software, based on the three-coordinate machine to measure and construct the geometric characteristics of the solid toric mirror, establish the workpiece coordinate system, which is consistent with the CAD model coordinate system. Finally, use the three-coordinate machine to perform scanning measurements to the solid toric mirror and compare the scanning result with the theoretical value to obtain the measurement result data. The measurement method of the present invention is based on the three-coordinate measurement technology and has the advantages of strong operability and high measurement accuracy.

A method of assembling a facet mirror of an optical system, in which facets of the facet mirror are imaged onto a field plane of the optical system, includes: a) determining positions of the facets of the facet mirror relative to interfaces of the facet mirror, with the aid of which the facet mirror is able to be connected to a support structure; b) calculating an actual position of an object field of the optical system arising for the facet mirror in the field plane; and c) arranging spacers between the interfaces and the support structure so that the object field in the field plane is brought from the calculated actual position to a target position.

A deformable minor system comprising: a deformable mirror surface; a plurality of actuators coupled to the mirror surface to deform the minor surface; and a detector coupled to the actuators to detect, for each actuator, an output signal from a driver of the actuator; and a controller coupled to each of the plurality of actuators, wherein the controller is configured, for each actuator, to: add a test signal to an input signal to form a modified input signal; send the modified input signal to the actuator; receive an indication of the output signal from the driver; determine when a test signal portion of the output signal satisfies a threshold condition; and in response to the test signal portion satisfying the threshold condition, control a subset of adjacent actuators to execute a shutdown sequence.

Disclosed herein is a circuit for determining failure of a movable MEMS mirror. The circuit includes an integrator receiving an opening angle signal representing an opening angle of the movable MEMS mirror, and a differentiator receiving the opening angle signal. A summing circuit is configured to sum the integrator output and the differentiator output. A comparison circuit is configured to determine whether the sum of the integrator output and differentiator output is not within a threshold window. An indicator circuit is configured to generate an indicator signal indicating that the movable MEMS mirror has failed based on the comparison circuit indicating that the sum of the integrator output and differentiator output is not within the threshold window.

Methods, devices, systems, and computer program products for estimating object reflectivity in a light detection and ranging (LIDAR) system are disclosed. The method, for example, includes receiving LIDAR data for a plurality of LIDAR scan cycles. The method also includes generating a dataset from the LIDAR data by accumulating the recorded return signals over the plurality of scan cycles. A data feature associated with an object is identified in the dataset, and one or more parameters of the data feature are identified. An estimated reflectivity of the object may then be determined based on the one or more parameters.