Abstract: A microlaser is described which is electrostatically tunable. One of the reflectors includes at least one reflecting part whose distance from the other reflector can be adjusted to change the effective optical distance between the reflectors and thus tune the optical frequency at which lasing occurs. The disclosure brings out that the inventive aspect is also applicable to other optical devices having reflectors defining a Fabry-Perot cavity. An optical interconnecting scheme for processors using the microlaser is also described.

Abstract: Quantum objects, such as atoms, ions, and molecules, are controllably moved by stimulating selected non-radiative energy levels within a quantum structure in accordance with the principles of stimulated Raman transitions. The movement is effected by timed excitation of individual quantum objects with preselected quantities ("pulses") of electromagnetic energy of at least two different frequencies which together are in resonance with a natural resonance (i.e., a stimulated Raman transition) of preferably metastable energy levels within the quantum object to cause a controlled change in momentum of the quantum object. Specific embodiments employ amplitude modulated collinear beams or multiple beams along different beam paths or collinear beams which are phase coherent but from independent laser sources.

Abstract: According to the invention, quantum objects, such as atoms, ions, and molecules, are controllably moved by stimulating selected non-radiative energy levels within a quantum structure in accordance with the principles of stimulated Raman transitions. The movement is effected by timed excitation of individual quantum objects with preselected quantities ("pulses") of electromagnetic energy of at least two different frequencies which together are in resonance with a natural resonance (i.e., a stimulated Raman transition) of preferably metastable energy levels within the quantum object to cause a controlled change in momentum of the quantum object. In alternative embodiments, single-pulse excitation or multiple-pulse sequence excitation with stimulated Raman transitions produce a controlled change in momentum of individual quantum objects according to the invention. A controlled distribution of velocities of an ensemble of quantum objects may be effected in accordance with the invention.

Abstract: Nucleic acids encoding all or part of a Yersinia ail gene are provided. The nucleic acid comprises at least 50 base pairs of a Yersinia ail gene in isolated form or consists or a fragment consisting essentially of at least 50 base pairs but not more than 50 kilo base pairs of a Yersinia ail gene. Such nucleic acids can also be operably linked to transcriptional and translational initiation and termination sequences which are functional in a microorganism host.

Abstract: The combination of a resonator having total internal reflection with a coupler providing coupling via frustrated total internal reflection. Both linear and non-linear embodiments are described. The linear embodiment is a spectrum analyzer. The non-linear embodiment is a second harmonic generator, although modifications are described for turning the same into an optical parametric oscillator.

Abstract: The invention relates to an apparatus including a semiconductor grating whose optical properties can be changed electrically in order to steer a diffracted laser beam with no moving parts. Lithographically defined portions, stripes or areas formed in a semiconductor quantum well region used in association with selectable voltage supply means enable control of the optical characteristics of the grating. The optical properties of the semiconductor quantum well region vary in response to variations in voltage applied to the areas which in turn change the transmissivity or reflectivity of the areas. By selectively applying voltages, the diffraction pattern obtained in the far-field from illuminating the areas is thus controlled and beam steering results. By using a two-dimensional array of areas, or alternatively using two such one dimensional arrays, beam steering in two dimensions may be accomplished.

Abstract: Live vaccines are provided and methods for preparing the live vaccines for protection of a host from a pathogenic microorganism. The vaccines are prepared by introducing at least one modification in a gene involved in at least one, normally at least two, biosynthetic pathways involving the production of products which are unlikely to be found in the disease susceptible host. The modification results in a gene change which cannot be repaired by a single step, e.g. polynucleotide deletions and inversions. Where the aro gene suffers such a change, the resultant auxotrophic mutants require aromatic amino acids, p-aminobenzoic acid and 2,3-dihydroxybenzoic acid or a highly concentrated source of absorabable iron. The auxotrophic mutations have substantially reduced or nonexistent virulence while retaining the desired immunogenicity to initiate the immunogenic response. Various techniques can be employed for providing the desired change.

Abstract: A system and method for non-intrusively obtaining the thrust value of combustion by-products of a jet engine is disclosed herein. The system includes laser elements for inducing absorption for use in determining the axial velocity and density of the jet flow stream and elements for calculating the thrust value therefrom.

Abstract: A method and apparatus for continuously introducing samples for mass spectrometry analysis which comprises providing sample molecules in an aqueous solution containing one or more organic solvents, preferably ethylene glycol, introducing said aqueous solution into the vacuum chamber of an ion source to enable said solution to solidify into a thread of solid matrix, and exposing the solid matrix to a source of energy to desorb sample molecules to be analyzed. The desorbed molecules are then photoionized and focused into a mass spectral analysis zone. The technique is suitable for interfacing liquid chromatographic separation techniques.

Abstract: A birefringent structure useful as a waveplate, grating, a hologram, a beam separator, a digital data storage medium or the like is formed by photo-exposure causing photo-reaction between photons and polymeric structures. In a specific embodiment, birefringence is induced by applying optical energy to a polymer film such as a polysilane with sufficient intensity to excite nonlinear absorption in the polymer film such that a pattern of the exposing optical energy is recorded in the polymer film. The optical energy is of a distinct polarization state such that the nonlinear optical efBACKGROUND OF THE INVENTIONThis invention was made under contract with or supported by the United States Air Force Office of Scientific Research under Contract No. AFOSR-88-0354. The Government has certain rights in this invention.

Abstract: Adaptive decision feedback equalizer apparatus for processing information stored on disk or tape media or the like including a data input buffer (34), a gain acquisition circuit (42), a timing acquisition circuit (40) operative to generate timing error signals for controlling the sampling phase of the read signals input to the input buffer, a synchronizing circuit (44) for generating sync detect signals and polarity signals, an FIR filter (36) for generating linear filter output signals, register means (39), feedforward update logic (38) for adjusting the equalizer coefficient signals to develop undated coefficient signals, a dual ported RAM (50) for storing a plurality of the equalizer coefficient signals, feedback logic (48) responsive to the linear filter output signals, equalizer coefficient signals obtained from the RAM, and train data signals, and operative to compute the equalizer error signals and equalizer output signals, feedback update logic (52) for adjusting the values of the coefficient signals

Abstract: An integrated scanning tunneling microscope and an integrated piezoelectric transducer and methods for making both. The device consists of one or two arm piezoelectric bimorph cantilevers formed by micromachining using standard integrated circuit processing steps. These cantilevers are attached to the substrate at one area and are free to move under the influence of piezoelectric forces which are caused by the application of appropriate voltages generated by control circuitry and applied to pairs of electrodes formed as an integral part of the bimorph cantilever structure. The electric fields caused by the control voltages cause the piezoelectric bimorphs to move in any desired fashion within ranges determined by the design. The bimorph cantilevers have tips with very sharp points formed thereon which are moved by the action of the control circuit and the piezoelectric bimorphs so to stay within a very small distance of a conducting surface.

Abstract: A birefringent structure useful as a waveplate, grating, a hologram, a beam separator, a digital data storage medium or the like is formed by photo-exposure causing photo-reaction between photons and polymeric structures. In a specific embodiment, birefringence is induced by applying optical energy to a polymer film such as a polysilane with sufficient intensity to excite nonlinear absorption in the polymer film such that a pattern of the exposing optical energy is recorded in the polymer film. The optical energy is of a distinct polarThis invention was made under contract with or supported by the United States Air Force office of Scientific Research under Contract No. AFOSR-88-0354. The Government has certain rights in this invention.

Abstract: Live vaccines are provided and methods for preparing the live vaccines for protection of a host from a pathogenic microorganism. The vaccines are prepared by introducing at least one modification in a gene involved in at least one, normally at least two, biosynthetic pathways involving the production of products which are unlikely to be found in the disease susceptible host. The modification results in a gene change which cannot be repaired by a single step, e.g. polynucleotide deletions and inversions. Where the aro gene suffers such a change, the resultant auxotrophic mutants require aromatic amino acids, p-aminobenzoic acid and 2,3-dihydroxybenzoic acid or a highly concentrated source of absorbable iron. The auxotrophic mutations have substantially reduced or nonexistent virulence while retaining the desired immunogenicity to initiate the immunogenic response. Various techniques can be employed for providing the desired change.

Abstract: TEM.sub.OOq laser radiation derived from a diode-pumped ring laser is directed into a faceted member of nonlinear optical material defining either a standing wave or ring monolithic optical resonator to generate harmonic laser radiation. The losses of the optical resonator, exclusive of the conversion loss to the harmonic, are made sufficiently low such that the dominant loss presented to the resonated mode of the optical resonator is the conversion loss to the generated harmonic. The reflectance of the input mirror of the optical resonator is impedance matched to the losses of the resonator including the harmonic conversion loss for optimum conversion efficiency. The length of the nonlinear optical material is shortened to the point where the bulk losses are less than ten times the sum of the surface and mirror losses, yielding conversion efficiencies of greater than 20 percent.

Abstract: A novel method of defining oligopeptides is provided for determining useful immunodominant sequences for use as vaccines for pathogens. The method involves identifying sequences by particular selection procedures and using such sequences with antigen-presenting cells and T-cells to demonstrate activation of the common histocompatibility antigens DQ and DR in humans and their analogs in other animals. The oligopeptides may then be used individually or in combination to produce safe and effective vaccines, where genes may be prepared encoding the oligopeptides and used for expression of the oligopeptides or combinations of the oligopeptides or the gene transformed into the appropriate host, e.g., B. pertussis, for use as a vaccine to the intact organism.

Abstract: Disclosed is a heterodimeric T lymphocyte receptor comprising an alpha and a beta subunit. Each subunit consists of a signal peptide, variable, joining, constant, transmembrane, and cytoplasmic regions. The two subunits are connected by a disulfide bond between cysteine residues located between the constant and transmembrane region.The structure, amino acid, and nucleotide sequence of the lymphocyte receptor were determined using CDNA clones derived from a functional murine cytotoxic T lymphocyte clone. The genes corresponding to these cDNA are expressed and rearranged specifically in T cells and have significant sequence homologies to immunoglobulin V and C genes.Both the T cell receptor protein and its subunits may be produced from the cDNA clones. The protein molecules may be further used for the production of T-cell clone specific antibodies.

Abstract: A cantilever stylus with an integrally formed conical tip is provided for atomic force microscopy AFM. The method for forming a stylus includes forming a circular masking pattern on the surface of a silicon substrate and anisotropically etching the silicon to form a post under the masking pattern. The post is then isotropically etched to produce a conical silicon tip mold. In one embodiment of the invention the silicon substrate and the conical silicon tip mold are thermally oxidized to form a cantilever stylus having including a cantilever arm with a conical tip fixed to its free end. In another embodiment of the invention the silicon substrate and the conical silicon tip mold are coated with a thin film of a dielectric material to form a cantilever stylus with a conical tip. In this embodiment the backside of the stylus is coated with a conductive material and a strong electric field is applied to the tip to cause electromigration of the conductive material to the point of the tip.

Abstract: In a three-mirror optical resonator, solid state laser, the gain member is a thin slab, such as Nd:glass, disposed at Brewsters angle to minimize insertion loss. The gain slab is disposed at a beam waist in a confocal arm of the optical resonator. Optical pumping radiation from a laser diode source is focused through one of the concave mirrors of the confocal arm of the resonator into the gain slab. The second arm of the resonator is defined between a planar mirror and one of the confocal mirrors. An acousto-optic mode-locking modulator is disposed in the collimated beam region of the resonator proximate the planar mirror. Additional pumping diodes pump collinearly through the other confocal mirror for higher power operation. The slab is rotated and translated to average thermally induced stress and de-focusing effects.

Abstract: A single instruction multiple data parallel processor has a rectangular array of processing elements which is smaller than the array of data to be processed. The array of data to be processed is divided into a number of segments, each equal in size to the processing element array. Each processing element includes a memory for storing one or more data values corresponding to one data element in each of these segments of the data array. To execute an instruction on all the data, the processing elements execute the instruction on one segment of the data array at a time, repeating the process until all the data has been processed. To do this, a primary address controller generates a sequence of segment address values for each instruction to be executed. The processing elements along the periphery of the processing element array are called edge processing elements.