Abstract: A holographic diffuser for use in conjunction with a back-lit flat-panel display and a source of illumination in the form of one or more tubular lamp segments is recorded so as to receive light from the lamp segments and scatter it preferentially along a plane perpendicular to the axis of the bulbs. In a back-lit display having vertically oriented tubular lamps, the diffuser scatters substantially more in the horizontal dimension, thus filling in the gaps of light intensity between the bulbs, which would otherwise be viewed by an observer, as with conventional diffusers. The high aspect ratio diffusers of the present invention are preferably formed by projecting coherent radiation through a mask having dimensions functionally related to the desired final aspect ratio, with an optional collimating lens being used to project that mask to infinity. A contact exposure process is also described.

Abstract: An optical spectrograph utilizes a plurality of holographic transmission optical gratings operative to receive an incoming source of light to be analyzed and diffract the light such that different spectral components impinge upon spatially separated regions of an opto-electronic detector. Various grating configurations are disclosed, including a physical stack of gratings conducive to extreme compactness, as well as a spaced-apart configuration used to preclude spectral cross talk in certain configurations. Diverging light emerging from a fiber-optic bundle is collimated by a first lens assembly prior to passing through the gratings, and a second lens assembly is used to focus the diffracted light onto the detectors, preferably in the form of a two-dimensional CCD array.

Abstract: An electronic video dental camera is provided which overcomes the disadvantages of both prior art dental mirrors, endoscopes, and video endoscopes. The electronic video dental camera is readily manipulated by dentists who are familiar with the manipulation of dental mirrors. Such an electronic video dental camera includes a handle to be held the user, and a camera head located at the distal end of the handle, with the camera head being formed at an angle to the handle, as in prior art dental mirrors. One embodiment includes provision for the flow of a selected fluid in order to defog and/or clean the camera lens. In one embodiment, the camera head includes light sources for illuminating the area to be viewed. In one embodiment, the handle of the dental camera includes means for transporting all appropriate signals and fluids to and from the camera head, and, if desired, valves and switching means located on the handle for controlling such communication to the camera head.

Abstract: Methods of recording and using holographic diffusers are disclosed for use with edge-lit backlight assemblies for transmissive flat-panel displays such as LCDs. When the holographic diffuser is supported against a surface of a backlight-emitting substrate it is operative to scatter the light in the direction of the display panel largely independent of angle of incidence. The recording methods may be used to produce both transmissive- and reflective-type diffusers, which may be employed simultaneously. In one embodiment a transmissive diffuser is used with a reflector and a cholesteric liquid crystal (CLC) polarizer. In this configuration, scatter lobes exhibiting the correct circular polarization are passed by CLC polarizer, whereas radiation of the opposite handedness is redirected toward the reflector, which converts the handedness into the form passable by the CLC polarizer.

Abstract: A pyroelectric detector assembly for detection of 10.6 .mu.m infrared laser radiation which has a thin film detector element fabricated from thin film lithium tantalate (LiTaO.sub.3) coated with black gold, and an ultra low noise charge coupled preamplifier optimized for lithium tantalate. A postamplifier includes a low pass filter, voltage comparator, threshold adjustment, and pulse generator.

Abstract: An electronic video dental camera is provided which overcomes the disadvantages of both prior art dental mirrors, endoscopes, and video endoscopes. The electronic video dental camera is readily manipulated by dentists who are familiar with the manipulation of dental mirrors. Such an electronic video dental camera includes a handle to be held the user, and a camera head located at the distal end of the handle, with the camera head being formed at an angle to the handle, as in prior art dental mirrors. One embodiment includes provision for the flow of a selected fluid in order to defog and/or clean the camera lens. In one embodiment, the camera head includes light sources for illuminating the area to be viewed. In one embodiment, the handle of the dental camera includes means for transporting all appropriate signals and fluids to and from the camera head, and, if desired, valves and switching means located on the handle for controlling such communication to the camera head.

Abstract: An electronic video dental camera is provided which overcomes the disadvantages of both prior art dental mirrors, endoscopes, and video endoscopes. The electronic video dental camera is readily manipulated by dentists who are familiar with the manipulation of dental mirrors. Such an electronic video dental camera includes a handle to be held the user, and a camera head located at the distal end of the handle, with the camera head being formed at an angle to the handle, as in prior art dental mirrors. One embodiment includes provision for the flow of a selected fluid in order to defog and/or clean the camera lens. In one embodiment, the camera head includes light sources for illuminating the area to be viewed. In one embodiment, the handle of the dental camera includes structure for transporting all appropriate signals and fluids to and from the camera head, and, if desired, valves and switching structure located on the handle for controlling such communication to the camera head.

Abstract: A wavefront sensor (10) includes a radiation sensor (2) and an array (12) of lenslets (12A) that are optically coupled to the radiation sensor. The array of lenslets has a radiation receiving surface for receiving an incident wavefront and for focussing the wavefront at a plurality of focal positions upon the radiation sensor. Each of the lenslets comprises a diffractive optical element having an optical center that is located at a predetermined point for inducing an equal and opposite tilt to a portion of the wavefront incident on the lenslet. As a result, an aberration within that portion of the wavefront is cancelled. The predetermined point is determined to be equal to and opposite a focal spot shift of the lenslet.

Abstract: A method and system for calibrating color filters employed in polychromatic imaging of a subject includes a scanning mirror (28), telescope (30), filters (104), and a detector array (60) employed for both imaging and calibration processes. A bundle (44) of optical fibers is employed for producing a slit-shaped beam of solar rays which are collimated and applied to a diffraction grating plate (54) or prism (72) to produce a set of dispersed solar rays. The dispersion is based on color. In one position of the scanning mirror, rays from a subject (12) to provide an image are directed through the telescope and scanned across the filters (104) and detectors (102). In another position of the scanning mirror, the set of dispersed solar rays is scanned past the filters and the detectors. Imaging data outputted by the detectors is collected for producing an image (112) of the subject. Data of the dispersed rays is collected for calibrating the color filters.

Abstract: Optical metrology apparatus includes one or more first sample point interferometers (SPIs) (16) having a wide dynamic range for measuring a rigid body position of a surface of a structure, such as a segmented mirror (11). At least one second SPI (18), having a lower dynamic range, is employed for measuring a figure of the segmented mirror. Either the first or the second SPIs may also be employed to measure a lateral displacement between the mirror segments (11a, 11b). The use of multiple SPIs, having differing dynamic ranges, within a closed-loop mirror control system is also described.

Abstract: A method is provided for calibrating a beamline (24) used for X-ray lithography. The beamline includes an elongated evacuated tube (28) extending from an X-ray source (22) for containing the X-ray beam to a closure (32) at an opposite end including a beryllium window. A target wafer (34) aligned with, but external of, the tube is positioned in a plane transverse of the X-ray beamline and is coated with a uniform layer of light sensitive material. A carbon filter (31) intermediate the X-ray source and the target wafer is provided within the tube to block electromagnetic radiation having wavelengths generally in the region of ultraviolet, visible, and infrared ranges of the spectrum. The beam from the X-ray source is scanned through the beamline, through the filter, and onto the target wafer. Thereafter, the wafer is subjected to an etch process thereby forming a contoured surface (34A) emulating the non-uniformities caused by the components of which the beamline is comprised.

Abstract: A device for controlling beams of particles, X-rays and gamma rays including a plurality of channels with total external reflection inner surfaces, input butt-ends facing a radiation source and output butt-ends aimed at a radiation receiver is taught. Channel-forming elements are in the form of surfaces, tubes, and structures with multiple channels and are rigidly positioned one relative to another with a spacing between supports such that the sagging of the channel-forming elements does not interfere with beam propagation. The device can be used to capture radiation from sources which produce parallel or divergent radiation. The resulting beam or beams can be of a variety of shapes or angular orientations including quasi-parallel, convergent, and split beams.

Abstract: An apparatus (10) for providing a consistent registration of a semiconductor wafer undergoing process work includes a platen (38) upon which a surround (14) is registered. The surround registers to the platen (38) by matching two pins (42), (40) that protrude from the platen (38) to a hole (44) and a notch (46) in the surround (14), respectively. A first registration surface (16) for registering a flat (20) of a semiconductor wafer (12) is permanently mounted to the surround (14). A second registration surface (18) for registering a point (24) on the circumference of the semiconductor wafer (12) is permanently mounted to the surround (14). A third, adjustable registration surface (26) also registers to a point (28) on the circumference of the wafer (12). This third registration surface (26) is springloaded to accommodate for slight diameter variations in successively processed semiconductor wafers, and to provide a force to hold the wafer (12) in place.

Abstract: The present invention is a technique for construction of a laser protection window providing broadened angular protection. Plural modulated index of refraction filter elements are constructed to reflect incident light at a predetermined laser threat wavelength over a cone of protection. The plurality of modulated index of refraction filter elements are disposed in tandem at angles to a direction of primary view through the laser protection window which are symmetrical with respect to the direction of primary view. In a first embodiment, a first optional modulated index of refraction filter element is disposed perpendicular to the direction of primary view; the other modulated index of refraction filter elements are disposed in pairs at opposing angles to the direction of primary view. In an alternative embodiment, the angled modulated index of refraction filter element plates are formed of angled segments.

Abstract: An X-ray lithography device which utilizes a Kumakhov lens is disclosed. This device is capable of using both small area sources and synchrotron sources. This device provides improved X-ray control, precision and accuracy. Also provided is a method of X-ray lithograph which incorporates a Kumakhov lens.

Abstract: A monochromator 18 has a thin faceplate which reduces temperature-induced distortion in a strain-free region by placing it close to a two-level heat exchanger 46, 64. The heat exchanger has a first level 46 in juxtaposition with the faceplate 22 for efficient heat extraction, and a second level 64 which establishes a constant temperature plane along a neutral bending axis of the monochromator 18. The first level heat exchanger is operated at a temperature below the zero CTE point of the silicon faceplate so that the integrated CTE of the faceplate is approximately zero. Pumps 30 and 32 are disposed respectively at the coolant inlets 26 and outlets 28 for fine-tuning the coolant pressure so that a minimal pressure across the faceplate 22 may be established to minimize bending moments on the thin faceplate.

Abstract: A standard thick silicon charge-coupled device (FIG. 1A) has its pixel face mounted to a transparent, optically flat glass substrate using a thin layer of thermoset epoxy. The backside silicon of the charge-coupled device is thinned to 10 .+-.0.5 um using a two-step chemi-mechanical process. The bulk silicon is thinned to 75 um with a 700 micro-grit aluminium oxide abrasive and is then thinned and polished to 10 um using 80 nm grit colloidal silica. Access from the backside to the aluminum bonding pads (36 of FIG. 5) of the device is achieved by photolithographic patterning and reactive ion etching of the silicon above the bonding pads. The charge-coupled device is then packaged and wire-bonded in a structure which offers support for the silicon membrane and allows for unobstructed backside illumination.

Abstract: Optical metrology method and apparatus wherein three optical wavelengths of a fixed polarization are generated and separated into a reference beam (RB) and a measurement or object beam (OB) having, ideally, equal optical path lengths. After reflecting from surfaces being measured OB is combined with RB and provided to sensors which measure the intensity associated with each of the wavelengths. Any difference between the intensities is indicative of a difference in the optical path lengths of OB and RB and is a function of the polarization state of each of the three returned wavelengths. Differences in optical path length may be indicative of a difference between a reference surface and a test surface, or a difference in thickness or index of refraction across an object. Two multi-mode laser diodes (12, 14) are provided for generating the three optical wavelengths.

Abstract: Optical metrology method and apparatus wherein three optical wavelengths are generated and separated into a reference beam (RB) and an object beam (OB) having substantially equal optical path lengths. After reflecting from a surface being measured OB is combined with RB and provided to sensors which measure the intensity associated with each of the wavelengths. Any difference between the intensities is indicative of a difference in the optical path lengths of OB and RB and is a function of the polarization state of each of the three returned wavelengths. Differences in optical path length are shown to be indicative of a displacement of the object being measured. Preferably, two multimode laser diodes (12,14) are provided for generating the three optical wavelengths. Two synthetic wavelengths are derived from the three optical wavelengths and are employed to improve the precision of measurement while retaining a large dynamic range made possible by the use of a large synthetic wavelength.

Abstract: A CW and/or pulse coherent radiation detection system (10) includes at least one radiation detector (14) having a plurality of discrete radiation detector elements (A-D) disposed upon a surface thereof. A coherence length discriminator (CLD), for example an etalon (12), is constructed so as to vary an optical path length therethrough at a plurality of locations. The CLD is disposed relative to the radiation detector such that radiation passing through the CLD is received by the discrete radiation detector elements. The apparatus further includes a drive (16) for translating the CLD relative to the radiation detector so as to modulate only coherent radiation passing through the CLD. The drive is preferably a reactionless drive having an energy consumption made small by the use of small CLD motions that correspond to the dimensions of individual detector elements. The coherent radiation detector is also shown to be usable for detecting an angle of arrival of coherent radiation.