Abstract: An embodiment of the present invention provides a method for designing optical surfaces. According to this method, m optical surfaces are defined, such that each successive optical surface receives a wavefront from a previous optical surface. Wavefront aberrations caused by each optical surface are calculated. The changes at each respective optical surface required to compensate for the wavefront aberration caused by the respective optical surfaces are then calculated. A desired optical profile for each of the m optical surfaces is determined in accordance with the calculated changes to each respective optical surface.

Abstract: A wavefront measurement system has a source of electromagnetic radiation. An imaging system focuses the electromagnetic radiation at an object plane. A first grating is positioned in the object plane and has a plurality of rulings with randomized height. A stage moves the first grating parallel to the rulings. A projection optical system projects an image of the first grating onto an image plane. A second grating is at the image plane. A detector behind the second grating receives a fringe pattern produced by the second grating.

Abstract: An electromagnetic radiation diffuser, operative at extreme ultraviolet (EUV) wavelengths, is fabricated on a substrate. The diffuser comprises a randomized structure having a peak and valley profile over which a highly reflective coating is formed. The reflective coating substantially takes the form of the peak and valley profile beneath it. An absorptive grating can be fabricated over the reflective coating. The grating spaces will diffusely reflect electromagnetic radiation because of the profile of the randomized structure beneath. The absorptive grating will absorb the electromagnetic radiation. The grating thus becomes a specialized Ronchi ruling that may be used for wavefront evaluation and other optical diagnostics in extremely short wavelength reflective lithography systems, such as EUV lithography systems.

Abstract: A wavefront measurement system has a source of electromagnetic radiation. An imaging system focuses the electromagnetic radiation at an object plane. A first grating is positioned in the object plane and has a plurality of rulings with randomized height. A stage moves the first grating parallel to the rulings. A projection optical system projects an image of the first grating onto an image plane. A second grating is at the image plane. A detector behind the second grating receives a fringe pattern produced by the second grating.

Abstract: An embodiment of the present invention provides a method for designing optical surfaces. According to this method, m optical surfaces are defined, such that each successive optical surface receives a wavefront from a previous optical surface. Wavefront aberrations caused by each optical surface are calculated. The changes at each respective optical surface required to compensate for the wavefront aberration caused by the respective optical surfaces are then calculated. A desired optical profile for each of the m optical surfaces is determined in accordance with the calculated changes to each respective optical surface.

Abstract: A wavefront measurement system has a source of electromagnetic radiation. An imaging system focuses the electromagnetic radiation at an object plane. A first grating is positioned in the object plane and has a plurality of rulings with randomized height. A stage moves the first grating parallel to the rulings. A projection optical system projects an image of the first grating onto an image plane. A second grating is at the image plane. A detector behind the second grating receives a fringe pattern produced by the second grating.

Abstract: An electromagnetic radiation diffuser, operative at extreme ultraviolet (EUV) wavelengths, is fabricated on a substrate. The diffuser comprises a randomized structure having a peak and valley profile over which a highly reflective coating is evaporated. The reflective coating substantially takes the form of the peak and valley profile beneath it. An absorptive grating is then fabricated over the reflective coating. The grating spaces will diffusely reflect electromagnetic radiation because of the profile of the randomized structure beneath. The absorptive grating will absorb the electromagnetic radiation. The grating thus becomes a specialized Ronchi ruling that may be used for wavefront evaluation and other optical diagnostics in extremely short wavelength reflective lithography systems, such as EUV lithography systems.

Abstract: An electromagnetic radiation diffuser, operative at extreme ultraviolet (EUV) wavelengths, is fabricated on a substrate. The diffuser comprises a randomized structure having a peak and valley profile over which a highly reflective coating is formed. The reflective coating substantially takes the form of the peak and valley profile beneath it. An absorptive grating can be fabricated over the reflective coating. The grating spaces will diffusely reflect electromagnetic radiation because of the profile of the randomized structure beneath. The absorptive grating will absorb the electromagnetic radiation. The grating thus becomes a specialized Ronchi ruling that may be used for wavefront evaluation and other optical diagnostics in extremely short wavelength reflective lithography systems, such as EUV lithography systems.

Abstract: An electromagnetic radiation diffuser, operative at extreme ultraviolet (EUV) wavelengths, is fabricated on a substrate. The diffuser comprises a randomized structure having a peak and valley profile over which a highly reflective coating is evaporated. The reflective coating substantially takes the form of the peak and valley profile beneath it. An absorptive grating is then fabricated over the reflective coating. The grating spaces will diffusely reflect electromagnetic radiation because of the profile of the randomized structure beneath. The absorptive grating will absorb the electromagnetic radiation. The grating thus becomes a specialized Ronchi ruling that may be used for wavefront evaluation and other optical diagnostics in extremely short wavelength reflective lithography systems, such as EUV lithography systems.

Abstract: A wavefront measurement system has a source of electromagnetic radiation. An imaging system focuses the electromagnetic radiation at an object plane. A first grating is positioned in the object plane and has a plurality of rulings with randomized height. A stage moves the first grating parallel to the rulings. A projection optical system projects an image of the first grating onto an image plane. A second grating is at the image plane. A detector behind the second grating receives a fringe pattern produced by the second grating.

Abstract: Apparatus for sampling a laser beam used in an analytical instrument, e.g., a clinical hematology or flow cytometer instrument, for measuring absorption by particles suspended in a stream moving through a flow cell. The laser beam is typically passed through a mask, e.g., a beam shaping aperture, to shape the beam. The shaped beam is then passed through a beam splitter, located downstream of the beam shaping aperture, so that one part of the shaped beam strikes the flow cell (e.g., is focused onto the moving stream of particles), and a second part is diverted to obtain a reference measurement of the beam about to strike the flow cell. An absorption measurement is obtained of the light passing through the flow cell, and a difference circuit is used to obtain a difference signal relating the differences between the measured absorption and the unabsorbed reference sample of the initial beam intensity.

Abstract: A horizon sensor having a pair of adjacent infrared detectors which view the earth's horizon either statically or by scanning is provided with a second order radiance correction to reduce errors in determining the true position of the horizon due to radiance variations of the earth due to changes in latitude and seasons particularly at lower altitudes. The second order correction is empirically determined from a large number of horizon profiles, and in two illustrative examples for different types of sensors, the correction may be readily obtained from a linear function related to the peak radiance of the horizon profiles.