Abstract: Precisely configured, especially of geometric shape, flakes of liquid crystal material are made using a mechanically flexible polymer mold with wells having shapes which are precisely configured by making the mold with a photolithographically manufactured or laser printed master. The polymer liquid crystal is poured into the wells in the flexible mold. When the liquid crystal material has solidified, the flexible mold is bent and the flakes are released and collected for use in making an electrooptical cell utilizing the liquid crystal flakes as the active element therein.

Abstract: A small boat or launch such as a motorized reinforced hull inflatable boat provides a platform for an acoustic source array of airguns. The array is made up as a ladder structure in which the airguns are disposed horizontally between vertical support and umbilical lines, preferably with their discharge ports in laterally offset or staggered relationship to minimize undesirable interactions between the acoustic transmissions released into the water by the sources and to help maximize the acoustic output of the array for a given array length. A structure stows the array on the boat for transport when the array is not deployed for use. If desired, the stowed array may be substantially enclosed by the hull of the boat. The stowage structure is preferable defined by a track or rails on the top of the deck. Umbilical cables attached to the array are translated, as by being wound on a drum and unwound therefrom, to deploy or retrieve the array over the stern of the boat.

Abstract: A long life laser wavelength meter is based on a Michelson interferometer with a flexure scanner. The scanner has a bar, preferably balanced about a pivot axis defined by a flexural pivot which supports the bar. Retroreflectors are mounted on the bar, equally spaced from the pivot axis. Long life is obtained by cycling or oscillating the bar over a limited range of angular movement within the bending limits of the flexure, which obtains a predicted, essentially infinite cycle life of the flexure. A large optical path length change for each scan of the oscillating bar is obtained through the use of the retroreflectors which fold the optical paths of each arm of the interferometer before reaching a fixed end mirror. The end mirror directs each optical path back through the same set of optical components, including the retroreflectors, to a beamsplitter which combines the light beams from both paths creating an optical interference beam output to a detector.

Abstract: Composite or layered flakes having a plurality of layers of different materials, which may be dielectric materials, conductive materials, or liquid crystalline materials suspended in a fluid host and subjected to an electric field, provide optical effects dependent upon the angle or orientation of the flakes in the applied electric field. The optical effects depend upon the composition and thickness of the layers, producing reflectance, interference, additive and/or subtractive color effects. The composition of layered flakes may also be selected to enhance and/or alter the dielectric properties of flakes, whereby flake motion in an electric field is also enhanced and/or altered. The devices are useful as active electro-optical displays, polarizers, filters, light modulators, and wherever controllable polarizing, reflecting and transmissive optical properties are desired.

Abstract: In order to make weather seals from closed cell elastomer foam material, molten plastic is extruded over a substrate of the foam material. Surface reactions during extrusion are avoided by continuously pulling the substrate through an oven chamber to degas (and remove moisture from) the material at least on its outside to a limiting thickness of the order of 10-30 mil to form a skin or crust. The extrusion of the over-coating is carried out to form a sleeve while the substrate is still hot. Since the skin is a degassed region on the outside of the foam substrate, reactions which may cause blistering and prevent the extrusion of a smooth and firmly adhering skin are avoided. The substrate material is preferably a thermosetting EPDM rubber closed cell foam, and the over coating material is a thermoplastic elastomer (TPE).

Abstract: In order to optimize detection of targets from a broadband return, a multiplicity of narrow bands are matched-filter processed simultaneously in parallel. The band or bands which provide the best joint combination of target and propagation in response are used for target detection.

Abstract: Pile weatherstripping is provided by a flat pile of strands which are tensioned to spring outwardly to straight condition to provide a pile weatherstrip, when bent and inserted into a T-slot or other kerf in a member such as a window or door frame or sash. The tendency of the bent parts of the pile to spring away from each other facilitates retention of the pile after insertion into the slot. A locking fin, more rigid than the pile, is preferably used. This locking fin engages steps or edges in the throat of the slot thereby impeding withdrawal of the weatherstripping from the slot. One or more barrier fins may also be assembled with the strands constituting the flat pile. The pile can be operated in bending mode or in columnar compression (crushing mode). Bending mode operation can be over a bending range so as to accommodate a large range of clearance between a sash and a frame or other members which are sealed by the pile weatherstripping.

Abstract: The quality of images produced by confocal microscopy, and especially scanning laser confocal microscopy, is enhanced especially for images obtained in turbid mediums such as many biological tissue specimens, by reducing speckle from scatterers that exist outside (above and below) the focal plane region which is being imaged by utilizing sheared beams, both of which are focused to spots in the focal or image plane (region of interest) and polarizing the beams to have opposite senses of circular polarization (right and left handed circular polarization). The return light from the image plane of certain polarization is detected after passing through the confocal aperture of the confocal microscope. Light from scatterers outside the region of interest, which are illuminated by both of the sheared beams, interfere thereby reducing speckle due to such scatterers, and particularly scatters which are adjacent to the image plane.

Abstract: In order to diagnose a strobe lamp system in a manner to isolate failure (burn out) of the strobe lamp from failures in its operating circuits, particularly the DC-DC converter which provides operating voltage to the lamp, a microcontroller, which produces sequences of signals corresponding to sequences of flashes from the lamp, is programmed so that the sequences of signals are not produced in the absence of output voltage from the DC-DC converter. The microcontroller is connected via a circuit including an LED to the circuit which converts the signals into trigger pulses for the strobe lamp. The failure of the strobe lamp to flash while the LED flashes isolates failures to the DC-DC converter, whereas flashing of the LED alone isolates failure to the lamp.

Abstract: An improved system for cellular surgery which includes a laser for producing a laser beam, and confocal optics for scanning and focusing the laser beam in tissue and generating confocal images of the tissue in accordance with returned light from the tissue. The confocal images are visualized on a display. The system includes a controller for enabling the operator to select one or more cells of the tissue in the displayed confocal images for surgical treatment. The controller operates the laser and confocal optics in a first mode to treat the tissue when the confocal optics focus the laser beam at least one region associated with the selected cells in the tissue, but at all other times operates the laser and confocal optics in a second mode which does not damage the tissue.

Abstract: Flakes or platelets of polymer liquid crystals (PLC) or other birefringent polymers (BP) suspended in a fluid host medium constitute a system that can function as the active element in an electrically switchable optical device when the suspension is either contained between a pair of rigid substrates bearing transparent conductive coatings or dispersed as microcapsules within the body of a flexible host polymer. Optical properties of these flake materials include large effective optical path length, different polarization states and high angular sensitivity in their selective reflection or birefringence. The flakes or platelets of these devices need only a 3-20° rotation about the normal to the cell surface to achieve switching characteristics obtainable with prior devices using particle rotation or translation.

Abstract: A system for the photometric calibration of streak cameras and similar imaging devices provides a precise knowledge of the camera's flat-field response as well as a mapping of the geometric distortions. The system provides the flat-field response, representing the spatial variations in the sensitivity of the recorded output, with a signal-to-noise ratio (SNR) greater than can be achieved in a single submicrosecond streak record. The measurement of the flat-field response is carried out by illuminating the input slit of the streak camera with a signal that is uniform in space and constant in time. This signal is generated by passing a continuous wave source through an optical homogenizer made up of a light pipe or pipes in which the illumination typically makes several bounces before exiting as a spatially uniform source field. The rectangular cross-section of the homogenizer is matched to the usable photocathode area of the streak tube.

Abstract: Pulse measurement for characterization of ultra-short optical pulses using spectral phase interferometry for direct electric field reconstruction (SPIDER) is enhanced by utilizing a plurality of spectral phase differences derived from the pulse and measured and frequency sheared replicas, which are temporally and/or spatially displaced, thereby providing spatial or temporal characterization or enhancing the temporal characterization of the input pulse in amplitude and phase. Improved interferometry which is not reliant on non-linear elements can be used.

Abstract: Amplitude and phase relative to an interferometrically established phase of ultrashort replica pulses (15) utilizes spectral phase interforemetry for direct electric field reconstruction by frequency shifting chirp replica pulses (16) of an optical pulse to be measured. The replicas of the pulses, relatively delayed in time, are generated by an interferometer (12).

Abstract: A marine towed array has a plurality of tow bodies of positive buoyancy each containing a marine acoustic source, such as a vibrator source. Each tow body uses a reel containing an electro-mechanical tow cable connecting the sources, whereby reeling and unreeling of the cable, controlled from a towing ship, changes the spacing of the tow bodies. One of the tow bodies at an end of the array is attachable to the towing ship.

Abstract: The quality of images produced by confocal microscopy, and especially scanning laser confocal microscopy, is enhanced especially for images obtained in turbid mediums such as many biological tissue specimens, by reducing speckle from scatterers that exist outside (above and below) the section which is being imaged by utilizing sheared beams, both of which are focused to laterally or vertically offset spots and polarizing the beams to have opposite senses of circular polarization (right and left handed circular polarization). The return light from the section of certain polarization is detected after passing through the confocal aperture of the confocal microscope. Images can be formed using optical coherence detection of the return light. Light from scatterers outside the section of interest, which are illuminated by both of the sheared beams, interfere thereby reducing speckle due to such scatterers, and particularly scatters which are adjacent to the section being imaged.

Abstract: A label printer feeds stock having peelable labels or without peelable labels fed by a platen roller against which a print head bears. A bail carrying a bail roller which is latchable in two positions, is provided. In one of these positions, the bail roller is away from the stock so that the stock is fed over a peeler bar, and in the other of the positions, the bail roller wraps the stock around the peeler bar. The latter position is used when the stock has peelable labels and is so called “linered” stock. The print head can print directly on the stock, and the stock having the printed labels is then fed out of the printer. In the second position, the labels are peeled off the stock as it travels around the peeler bar and can be removed by the user while the liner from which the labels have been peeled leaves the printer. No rethreading of stock is required to handle different types of stock, thereby increasing the flexibility and simplifying the operation of the label printer.