Abstract: A detector system for spatially resolved detection of a gas substance in an area is described. The detector system includes a detector comprising an image sensor; a band filter arranged in an optical beam path before the detector for transferring a beam with a wavelength spectrum including an absorption wavelength corresponding to the gas substance, a telescope, a polarizing beam splitter, and an interferometric stage including a retarder for creating an optical path difference for measuring absorption dips due to the presence of the gas substance. The retarder includes multiple birefringent media arranged with the optical axes relative to each other so that at least one increases an optical path difference and at least one decreases an optical path difference between the polarized beam components, and the thicknesses of the birefringent media are tuned to minimize a focal shift between the polarized beam components.

Abstract: A telescope system (100) comprises a steering minor (M5) arranged in a part of its optical path (L5-L6) between a first telescope stage (10) and a second telescope stage (20). The steering mirror (M5) is configured to controllably rotate over a rotation angle (?m) for controlling a view angle (?v) of the telescope system (100) from the entrance aperture (A1). The steering mirror (M5) is disposed at an intermediate pupil (Pi) of the telescope system (100), at which position an image of the aperture stop (As) is formed by one or more of the optical components (M7, M6) there between.

Abstract: Interferometer system, including optical means (2, 3, 4, 5) arranged for directing light along a first interferometer path and (separate) second interferometer path, and for combining the light for allowing interferometry, characterized in that the first interferometer path (PI) is provided with a first light transmitting structure (10) having a rotational position that is adjustable with respect to an optical axis of the first path.

Abstract: A telescope system (100) comprises a steering minor (M5) arranged in a part of its optical path (L5-L6) between a first telescope stage (10) and a second telescope stage (20). The steering mirror (M5) is configured to controllably rotate over a rotation angle (?m) for controlling a view angle (?v) of the telescope system (100) from the entrance aperture (A1). The steering mirror (M5) is disposed at an intermediate pupil (Pi) of the telescope system (100), at which position an image of the aperture stop (As) is formed by one or more of the optical components (M7,M6) there between.

Abstract: Correction optics (10) are disposed in an optical path directly behind an entry slit (1) of a spectrometer (100) and configured to warp a straight object line shape (A1) of the entry slit (1) into a curved object line shape (B1) from a point of view of the projection optics (2,3,4). The warping of the correction optics (10) is configured such that a curvature (R1) of the curved object line shape (B1) counteracts an otherwise distorting curvature (R5) in a projection (A5) of the straight object line shape (A1) by the projection optics (2,3,4) without the correction optics (10). As a result, the spectrally resolved image (B5) comprises a plurality of parallel straight projected line shapes formed by spectrally resolved projections of the straight object line shape (A1).

Abstract: An aerosol detector system is described for spatially resolved detection of an aerosol distribution in an area. The system includes a wide field polarization preserving telescope having telecentric imaging optics for imaging the earth surface onto a detector that receives phase stepped images from the telescope, A controller is arranged to provide a resulting image as a function of corresponding pixel values of the multiple images to produce an image at a spatially resolved polarization state corresponding to said aerosol substance.

Abstract: Correction optics (10) are disposed in an optical path directly behind an entry slit (1) of a spectrometer (100) and configured to warp a straight object line shape (A1) of the entry slit (1) into a curved object line shape (B1) from a point of view of the projection optics (2,3,4). The warping of the correction optics (10) is configured such that a curvature (R1) of the curved object line shape (B1) counteracts an otherwise distorting curvature (R5) in a projection (A5) of the straight object line shape (A1) by the projection optics (2,3,4) without the correction optics (10). As a result, the spectrally resolved image (B5) comprises a plurality of parallel straight projected line shapes formed by spectrally resolved projections of the straight object line shape (A1).

Abstract: The invention pertains to a method of spatially resolved detection of a gas substance in an area, comprising: imaging the area on a first image sensor, in a wavelength spectrum including an absorption wavelength peak corresponding to said gas substance; imaging the area on a second image sensor, to provide for each pixel of the first image a corresponding pixel of the second image for respective on- and off-peak wavelengths relative to the absorption wavelength; and providing a difference image as a function of the two pixel values of first and second image sensors to produce an image of the spatially resolved absorption wavelength corresponding to said gas substance.

Abstract: Interferometer system, including optical means (2, 3, 4, 5) arranged for directing light along a first interferometer path and (separate) second interferometer path, and for combining the light for allowing interferometry, characterized in that the first interferometer path (PI) is provided with a first light transmitting structure (10) having a rotational position that is adjustable with respect to an optical axis of the first path.

Abstract: The invention pertains to an aerosol detector system for spatially resolved detection of an aerosol distribution in an area, comprising: a wide field polarization preserving telescope having telecentric imaging optics for imaging the earth surface onto a detector; said detector receiving phase stepped images imaged by said telescope; and a controller coupled to the detector, arranged to provide a resulting image as a function of corresponding pixel values of the multiple images to produce an image at a spatially resolved polarization state corresponding to said aerosol substance; wherein the telescope comprises a first telecentric imaging lens group and a wavelength filter positioned in a field image of the first telescope telecentric beam to define a spectral range of interest; the telescope further comprising: a converging lens group converging the beam to a pupil stop; relay optics including a second telecentric imaging lens group arranged to generate a telecentric beam; and splitter optics, comprising a p

Abstract: The invention pertains to a method of spatially resolved detection of a gas substance in an area, comprising: imaging the area on a first image sensor, in a wavelength spectrum including an absorption wavelength peak corresponding to said gas substance; imaging the area on a second image sensor, to provide for each pixel of the first image a corresponding pixel of the second image for respective on- and off-peak wavelengths relative to the absorption wavelength; and providing a difference image as a function of the two pixel values of first and second image sensors to produce an image of the spatially resolved absorption wavelength corresponding to said gas substance.

Abstract: A light beam is applied to a front surface of an optical depolarizer. The depolarizer rotates the polarization of light received on different surface positions by different amounts, so that the average incoming polarization is scrambled. The depolarizer has a first and second body that transmit first and second polarization components of the beam with mutually different speeds of light. Each body has two wedge shaped parts of variable thickness, corresponding wedge shaped parts in the two bodies providing light paths of substantially position independent lengths, but with variable rotation of polarization. The wedge shape parts of the front body form a concave input surface for the incoming beam. This prevents cross-over of light between the different wedge shaped parts.

Abstract: A manufacturing method for a grating is disclosed for the angular dispersion of light impinging the grating. The grating comprises tapered structures and cavities. A cavity width and/or corrugation amplitude is varied for achieving a desired grating efficiency according to calculation. A method is disclosed for conveniently creating gratings with variable cavity width and/or corrugation amplitude. The method comprises the step of anisotropically etching a groove pattern into a grating master. Optionally a replica is produced that is complementary to the grating master. By variation of an etching resist pattern, the cavity width of the grating may be varied allowing the optimization towards different efficiency goals.

Abstract: An anamorphotic telescope has mutually different magnification along directions of minimum and maximum magnification in an image plane. A spectroscope with an elongated input slit directed along one of the directions of maximum and minimum magnification may be located in the image plane. The anamorphotic telescope has a first and second reflector lens with mutually different first and second radii of curvature in directions (y, x) that optically correspond to directions of minimum and maximum magnification. At least one of the first and second reflector lens has a variable radius of curvature in one direction (x), which varies as a function of position in the other direction (y), the variable radius of curvature decreasing in a direction of the angle from the view direction to the light directed by the first reflector lens to the second reflector lens.

Abstract: A manufacturing method for a grating is disclosed for the angular dispersion of light impinging the grating. The grating comprises tapered structures and cavities. A cavity width and/or corrugation amplitude is varied for achieving a desired grating efficiency according to calculation. A method is disclosed for conveniently creating gratings with variable cavity width and/or corrugation amplitude. The method comprises the step of anisotropically etching a groove pattern into a grating master. Optionally a replica is produced that is complementary to the grating master. By variation of an etching resist pattern, the cavity width of the grating may be varied allowing the optimization towards different efficiency goals.

Abstract: A light beam is applied to a front surface of an optical depolarizer. The depolarizer rotates the polarization of light received on different surface positions by different amounts, so that the average incoming polarization is scrambled. The depolarizer has a first and second body that transmit first and second polarization components of the beam with mutually different speeds of light. Each body has two wedge shaped parts of variable thickness, corresponding wedge shaped parts in the two bodies providing light paths of substantially position independent lengths, but with variable rotation of polarization. The wedge shape parts of the front body form a concave input surface for the incoming beam. This prevents cross-over of light between the different wedge shaped parts.

Abstract: Apparatus and methods are used to calibrate an array of individually controllable elements within a lithographic apparatus. A calibration unit can switch between a first state in which the modulated beam of radiation passes into a projection system for projecting the modulated beam of radiation onto a substrate and a second state in which a portion of the modulated beam of radiation is inspected by the calibration unit. The calibration unit generates calibration data, or alternatively, updates calibration data, based on the inspection of the modulated beam of radiation. An array controller uses the calibration data to provide control signals to elements of an array of individually controllable elements, which are subsequently configured in response to the control signals.

Abstract: An anamorphotic telescope has mutually different magnification along directions of minimum and maximum magnification in an image plane. A spectroscope with an elongated input slit directed along one of the directions of maximum and minimum magnification may be located in the image plane. The anamorphotic telescope has a first and second reflector lens with mutually different first and second radii of curvature in directions (y, x) that optically correspond to directions of minimum and maximum magnification. At least one of the first and second reflector lens has a variable radius of curvature in one direction (x), which varies as a function of position in the other direction (y), the variable radius of curvature decreasing in a direction of the angle from the view direction to the light directed by the first reflector lens to the second reflector lens.

Abstract: A lens element, for use in a projection system, includes a concave side. The lens element further includes a membrane and a nozzle, the membrane at least covering the concave side of the lens element. The nozzle is arranged for supplying and/or removing a liquid and/or a gas in between the concave side and the membrane.

Abstract: Apparatus and methods are used to control a polarization state of a radiation beam. A polarization control unit is configured to modulate a polarization state of at least a part of a radiation beam. A determination arrangement is configured to subsequently determine the polarization state of the at least a part of the radiation beam. A feedback unit is configured to provide signals to the polarization control arrangement based on at least the determined polarization state in order to correct for deviation in the polarization state of the part of the radiation beam from a desired polarization state. For example, the correction may ensure that the polarization state of the part of the radiation beam is at, or returns to, the desired polarization state.