Abstract: A major/minor loop bubble memory system architecture includes a passive replicator in the major loop read channel which is connected by a first path to a mode switch-annihilator and a merge point in the major loop write channel and by a second path to an off-chip decision-making means and the merge point in the write channel. The decision-making means is positioned the same or fewer propagation steps than the mode switch-annihilator is from the replicator. The decision making means is activated to cause either the replicated data to pass through the mode switch-annihilator into the write channel or the replicated data to be annihilated in the mode switch-annihilator and the data from a generator to pass into the write channel.

Abstract: An electrolyte for an electrochromic display of the kind in which a persistent colored species of an electrochromic substance in solution is deposited onto a display electrode upon the passage of current therethrough is disclosed. The electrolyte comprises an aqueous solution of a di-alkyl bipyridinium salt and a non-polymeric aliphatic alcohol in which either: (a) both alkyl groups of the bipyridinium salt have an odd number of carbon atoms and the alcohol has an even number of carbon atoms; or (b) both alkyl groups of the bipyridinium salt have an even number of carbon atoms and the alcohol has an odd number of carbon atoms. The presence of an alcohol in the electrolyte inhibits recrystallization (spotting) and non-erasure of the display electrodes. A particularly effective alcohol for 1,1' di-heptyl 4,4' bipyridinium dibromide, which has a severe lifetime problem, is n-hexanol.

Abstract: A multiple electron beam cathode ray tube has a plurality of cathodes in a plane to form an array. Grids on the same substrate are positioned in spaced relation about the cathodes so that a plurality of individually controlled electron beams are formed when appropriate potentials are applied to the cathodes and grids.

Abstract: A method for adjusting the orientation of the rotation axis for a sample in a nuclear magnetic resonance (NMR) experiment includes using a field gradient in a specific direction with respect to the external magnetic field of the NMR experiment to establish a calibrated reference direction with which the rotation axis may be aligned. Preferably, the magnetic field gradient is at an angle of 54.7.degree.. A preferred embodiment of this invention includes automatic control steps in the method.

Abstract: A cathode for reactive ion etching is provided which improves the etch rate and the uniformity of etching on the object etched. The cathode has a quartz plate with a series of recesses having disks therein of the same material as the object to be etched and a ring of that same material around the outer edge of the plate. In a preferred embodiment a cathode for etching silicon wafers has silicon disks recessed in a quartz plate at each wafer holding position and a ring of silicon around the outer edge of the plate.

Abstract: A holder for liquid phase epitaxial (LPE) growth which eliminates mesas on the surface of the film is described. The holder has two legs to which a ring is connected. The ring has holding means so that it can hold one wafer or two wafers back-to-back. One of the two legs extends vertically below the first ring. In a preferred embodiment a second ring having holding means for a pair of wafers back-to-back is attached to the elongated leg. This holder structure prevents a film from the liquid melt from forming when the holder is withdrawn from the liquid growth solution, thereby eliminating the formation of mesas which occur when the film ruptures.

Abstract: A method and device for detecting Neel wall segments in a cross-tie memory system involves applying a magnetic field to the Neel wall segments of a given polarity so that these Neel wall segments expand into a transverse domain. The transverse domain is then sensed with a magnetoresistive detector.

Abstract: A propagation track for use in contiguous disk bubble devices consists of a plurality of spaced dovetail shaped elements which are connected at one end thereof by a track portion which faces in the direction of and is substantially perpendicular to the (1,1,2) axis. The first, third and fifth sides of the dovetail structure are elongated and also face in the direction of and are substantially perpendicular to the (1,1,2) axis. The remaining sides of the dovetail structure have different orientations, the second side facing in the direction of and being substantially perpendicular to the (2,1,1) axis, and the fourth side facing in the direction of and being substantially perpendicular to the (1,2,1) axis. The orientation of the two cusps formed by the first and second sides and the fourth and fifth sides is such that the lines bisecting and pointing toward the cusps are substantially parallel to the (1,2,1) and (2,1,1) axes, respectively.

Abstract: A propagation pattern for contiguous disk bubble devices consists of a plurality of parallel propagation tracks in which each propagation track is asymmetric. Adjacent propagation tracks are positioned so that the cusps that face each other are aligned therewith. The region between adjacent tracks forms two subregions which are mirror images of each other when the region is bisected by a longitudinal midplane.

Abstract: A permalloy-first bubble switch has two curved propagation elements positioned on a layer of bubble domain supporting material. A curved conductor is superimposed on top of the propagation elements so that a current passing through the conductor element permits a bubble to be moved from one curved propagation element to the second curved propagation element.

Abstract: A resistive ribbon thermal transfer printing apparatus has an improved ribbon configuration. The ribbon contains a two-ply resistive element positioned on a conductive layer. The resistive element contains a top layer having a low resistance, for example 3.times.10.sup.-5 .OMEGA. for making contact with the writing head and a bottom layer having a higher resistance, for example 1.times.10.sup.-3 .OMEGA. in contact with the conductive layer for generating heat. The ratio of the resistance of the high resistance layer to the resistance of the low resistance layer, R.sub.H /R.sub.L, is 1.1 to 1000. An example of such a ribbon contains a top resistive layer of polyimide containing 35% conductive carbon, a bottom resistive layer of a SiO/Cr cermet (60%/40%), a stainless steel conductive layer and a Versamid ink layer.

Abstract: A method of electrochemically etching a semiconductor to a predetermined contour includes positioning at least one electrode on one side of the semiconductor and then applying a voltage to the electrodes so as to generate a varying current density vertically through the semiconductor and thereby electrochemically etch the mask-free other side of the semiconductor.

Abstract: An optical pulse shaping device and methhod of shaping an optical pulse involves the use of a phase coherent multi-frequency light beam with an optical element consisting of a sample containing an absorption band with multiple holes. The holes are burned into the sample to selected depths at selected frequency locations, thereby permitting the relative phases and amplitudes of the input frequency components of the beam to be independently varied to arbitrary values. This system enables a generalized Fourier synthesis of optical pulses such as a laser with designed temporal profiles to be effected.

Abstract: An electrochromic display device has a polymer film on the display electrode. In the writing step the polymer film on the display electrode is oxidized to a colored, non-transparent form. In the erasing step the polymer film is reduced to a neutral transparent form. A film of polyaniline is used in a preferred embodiment. A film of polypyrrole is used in another embodiment.

Abstract: An apparatus and a method for rotary electroplating a thin metallic film having a uniform thickness and composition throughout. The apparatus includes a flow-through jet plate having nozzles of increasing size and uniformly spaced radially therethrough, or the same sized nozzles with varying radial spacing therethrough so as to provide a differential flow distribution of the plating solution that impinges on the wafer-cathode where the film is deposited. The spacing and size of the nozzles are critical to obtaining a uniform thickness. The electrical currents to the wafer and to the thieving ring are controlled by variable resistors so as to keep the electrical current to the cathode constant throughout the plating process. In a preferred embodiment the flow-through jet plate has an anode associated therewith in which the exposed area of the anode is maintained at a constant amount during the deposition.

Abstract: A method for spin imaging in solids using nuclear magnetic resonance (NMR) spectroscopy. The invention includes the steps of rotating the sample about an axis which makes a particular angle with the NMR static external magnetic field, rotating a magnetic field gradient with a spatial distribution which is related to the sample spinning axis synchronously with the sample, collecting the data while performing a solid state NMR line narrowing step, and changing the phase relation between the sample rotation and the field gradient rotation on a step-by-step basis to map out an image of the object.

Abstract: A method and device for detecting a narrow spectral feature in a sample is described. The method includes the steps of providing a beam of light having an optical frequency bandwidth which is narrow compared to the width of the narrow spectral feature and having a center frequency .omega..sub.C which lies near the narrow spectral feature, phase modulating the beam of light with a single RF frequency to provide a pure FM spectrum having upper and lower sidebands, exposing the sample containing the narrow spectral feature to the modulated light so that only one of the FM sidebands probes the narrow spectral feature, photodetecting the light emerging from the sample to detect a RF beat at the specific RF frequency used for phase modulation, and electronically monitoring the amplitude of the RF beat signal to indicate the strength of the narrow spectral feature. A preferred embodiment of this invention is a multiplex readout device for hole burning memories.

Abstract: Lithographic resist compositions are provided which permit an improved lift-off process in which the deposition mask with apertures has the desirable negative slope or overhang. The resist composition comprises a phenolic-aldehyde resin, a photosensitizer and Meldrum's diazo, or Meldrum's acid or suitable analogs thereof as a profile modifying agent. The profile modifying agents useful in the present invention have the formula: ##STR1## wherein R.sub.1 is C.sub.1 to C.sub.20 alkyl or aryl, R.sub.2 is H, C.sub.1 to C.sub.20 alkyl or aryl, or together R.sub.1 and R.sub.2 are cycloalkyl, A is N or H.

Abstract: A parametric bubble detector contains a coupled film sensor stripe and an excitation conductor which, electrically insulated from each other, cross at right angles. A sensor stripe consists of a pair of superpositioned Permalloy stripes which are separated by a thin nonmagnetic layer. A high frequency excitation current in the conductor produces an inductive output signal in the sensor stripe. The waveform of this periodic signal is responsive to bubble domains proximate to the sensor/conductor crossover area.

Abstract: A close-packed magnetic bubble propagation device includes a pattern having a plurality of propagation elements positioned in at least four adjacent rows. These elements are spaced to provide a period or spacing of bubbles in these rows of less than three bubble diameters. Upon application of a rotating in-plane field to the elements, bubbles in adjacent rows move in opposite directions. A preferred embodiment of this propagation device has at least two storage loops which contain at least four adjacent horizontal rows of propagation elements. A preferred device utilizing this pattern has at least two storage loops and an access path which passes through each of the loops. An electrical conductor is associated with the propagation elements in the access path so that the passing of a current through the conductor together with the application of an in-plane rotating field to the elements causes bubbles associated with the elements in the access path to move along the access path.