Abstract: The invention relates to a method of determining a parameter relating to image blur in an imaging system (IS) comprising the step of illuminating an object having a test pattern (MTP) by means of the imaging system (IS), thereby forming an image of the test pattern. The test pattern (MTP) has a size smaller than the resolution of the imaging system (IS), which makes the image of the test pattern independent of illuminator aberrations. The test pattern (MTP) is an isolated pattern, which causes the image to be free of optical proximity effects. The image is blurred due to stochastic fluctuations in the imaging system and/or in the detector detecting the blurred image. The parameter relating to the image blur is determined from a parameter relating to the shape of the blurred image. According to the invention, resist diffusion and/or focus noise may be characterized. In the method of designing a mask, the parameter relating to the image blur due to diffusion in the resist is taken into account.

Abstract: A reflector for EUV has additional multi-layers on the front surface of a base multilayer stack provided selectively to compensate for figure errors in the base multilayer stack or the substrate on which the multilayer stack is provided. A reflective mask for EUV uses two multilayer stacks, one introducing a relative phase shift and/or altered reflectivity with respect to the other one.

Abstract: A reflector for EUV has additional multi-layers on the front surface of a base multilayer stack provided selectively to compensate for figure errors in the base multilayer stack or the substrate on which the multilayer stack is provided. A reflective mask for EUV uses two multilayer stacks, one introducing a relative phase shift and/or altered reflectivity with respect to the other one.

Abstract: The present invention relates to an achromatic phase shift device (1) for introducing a wavelength independent optical phase shift in a first optical beam (40) during operation, comprising at least one dispersive element (55k) formed by first refractive means (2k) and second refractive means (4k), the first refractive means (2k) having a first refractive means input plane (6) for receiving the first optical beam (40) and a first refractive means output plane (8) being at a predetermined angle (&bgr;) to each other, the second refractive means (4k) having a second refractive means input plane (10) and a second refractive means output plane (12) being positioned parallel to the first refractive means input plane (6). The device may comprise further pairs (55k) of respective first and second refractive means (2k, 4k). The present invention also relates to an interferometer comprising at least one achromatic phase shift device.

Abstract: A reflector for EUV has additional multi-layers on the front surface of a base multilayer stack provided selectively to compensate for figure errors in the base multilayer stack or the substrate on which the multilayer stack is provided. A reflective mask for EUV uses two multilayer stacks, one introducing a relative phase shift and/or altered reflectivity with respect to the other one.

Abstract: A classification system for systems of n mirrors, whereby systems of mirrors are classified by a number C, is defined as follows: C = ∑ i = 1 n ⁢ a i · 2 ( n - i ) ⁢ ( M &LeftBracketingBar; M &RightBracketingBar; ) where: ai=1 if the angle of incidence of the chief ray at mirror i is negative, ai=0 if the angle of incidence of the chief ray at mirror i is positive, M is the magnification of the projection system, and index i numbers the mirrors of the system in series.

Abstract: A reflector for EUV has additional multi-layers on the front surface of a base multilayer stack provided selectively to compensate for figure errors in the base multilayer stack or the substrate on which the multilayer stack is provided. A reflective mask for EUV uses two multilayer stacks, one introducing a relative phase shift and/or altered reflectivity with respect to the other one.

Abstract: A lenticular device in which first and second arrays of lenticular elements are located on first and second surfaces of the device.

Abstract: A disc-shaped record carrier is described on which information is recorded in an optical structure of trackwise arranged areas and intermediate areas. By adapting the average dimensions of the areas to the average spatial frequencies on the record carrier a read signal can be obtained of sufficient modulation depth and minimal distortion. This is accomplished by increasing the track width with decreasing radius of the record carrier.

Abstract: An apparatus as described for reading a record carrier on which information, for example video and/or audio information is stored in an optically readible track-shaped information structure. A deviation between the center of a read spot which is projected on the information structure and the center line of a track to be read can be detected with the aid of at least two detectors which are disposed in the far field of the information structure in different quadrants. With the aid of the same detectors a reference signal is obtained which is used for deriving a control signal for correcting the position of the read spot relative to the track to be read.

Abstract: An apparatus is described for reading a record carrier, on which information, for example video and/or audio information, is stored in an optically readable track-shaped information structure. Errors in the focussing of a read beam relative to the plane of the information structure can be detected with the aid of two detectors which are disposed in the far field of the information structure, which detectors are arranged at one side of a plane defined by the optical axis of an objective system and a line which effectively extends transversely to the track direction and which longitudinal direction are effectively transverse to the track direction. With the aid of the same detectors a reference signal is obtained, which is employed for deriving a control signal for focussing correction of the read beam.

Abstract: An apparatus is described for reading a flat record carrier on which information is stored in an optically readable track-shaped information structure. By the arrangement in the far field of the information structure and at one side of a plane which is formed by the optical axis of an objective system which is used for reading and a line parallel to the center line of the track portion to be read, of a radiation-sensitive detection system which consists of at least two detectors in approximately the position .beta./2, .beta. being the angle at which a first-order beam is diffracted in the lateral direction of the tracks, centering and focussing errors can be detected without the use of auxiliary beams and additional optical elements.

Abstract: An opto-electronic system is described for determining a deviation between the actual position of a radiation-reflecting plane in an optical imaging system and the desired position of said plane. Two auxiliary radiation sources are provided which are shifted in opposite directions relative to the optical axis of the imaging system and two radiation-sensitive detectors which are also shifted in opposite directions relative to the optical axis of the imaging system. Of the set of auxiliary radiation sources and the set of detectors the elements of one set are shifted relative to each other in the direction of the optical axis. The auxiliary radiation sources may be formed with the aid of a Fresnel zone plate.

Abstract: A record carrier is described in which a television signal is stored in an optically readable information structure of trackwise arranged areas alternating with intermediate areas. The tracks exhibit an undulation. The luminance information is contained in the spatial frequency of the areas and the other information, for example chrominance and sound information, in the variation of the undulation. The luminance information and the other information can be read independently by means of a suitable detector arrangement.