Science Research Laboratory, Inc.

Avco Everett Research Laboratory, Inc.

Avco Corporation

Corporation for National Research Initiatives

Allen M Flusberg

Shrenik Deliwala

Mordechai Rokni

Jonah H Jacob

Ruth E Shefer

Robert E Klinkowstein

Michael A Huff

James L Moran

Barbara J Hughey

Martin A Jaspan

Israel Smilanski

Stephen D Swartz

Paul Lewis

Image acquisition systems utilizing a pixilated transducer.

Systems for image acquisition

Methods for fabricating structures such as transducer pedestal structures and transducers fabricated by the methods.

Fabrication of transducer structures

Image acquisition methods and systems utilizing a pixilated transducer.

Systems and methods for image acquisition

Methods and apparatus for maintaining a quality of a Raman medium in a Raman conversion cell. In various examples, a flow velocity of the Raman medium is tailored based on a spatial nonuniformity of heat deposition resulting from the Raman conversion in the cell. In particular, in one example, the flow velocity of the Raman medium may be tailored to be higher where the heat deposition/temperature rise is larger and smaller elsewhere in the cell. This type of flow velocity profile reduces the overall required volumetric flow of the Raman medium in the cell without significantly affecting a quality of the Raman medium.

Methods and apparatus for maintaining a quality of a Raman medium in a Raman conversion cell

Methods and systems enabling enhanced bit-rate QKD fiber-based key delivery. In one embodiment, a secure communications network of this invention includes a number of communication nodes, each of the communication nodes being connected to a quantum channel. At least one of the communication nodes (a sending node) includes a multiplexing system capable of assembling a succession of substantially single photons in a predetermined order. At least another of the communication nodes (a receiving node) includes a receiving system capable of receiving at least some of the assembled succession of substantially single photons, a demultiplexing system capable of separating the received assembled succession of substantially single photons into a number of separated successions of substantially single photons, and, a number of detector systems, each one of the detector systems being capable of detecting one separated succession of the successions of substantially single photons.

Methods and systems for high-data-rate quantum cryptography

A method and apparatus for enhancing the precision of distance or position measurements using a two-wavelength interferometer is disclosed. The invention provides for the direct measurement of air density fluctuations, thus allowing for correction of measurement errors, including those due to air turbulence and air thermal variations in a measurement path of a distance measuring interferometer. The invention can function both as a precision enhancement to an existing interferometric measuring system, or as a stand-alone system, measuring both &ldquo;uncorrected&rdquo; distance and air density and providing a corrected distance value. A novel measurement head design removes the constraint that a measurement and a reference component of the interferometer optical signals travel a shared path at any point in the interferometer, and thus substantially reduces errors due to polarization leakage. A novel signal processing technique reduces the cost, size and complexity of a distance or position measurement system according to the invention, and renders the invention particularly useful for lithographic integrated-circuit wafer production applications with critical dimensions below 0.1 &mgr;m.

Method and apparatus for enhanced precision interferometric distance measurement

An ultra high resolution wave focusing method and apparatus is disclosed. The invention provides a focusing system having an effective numerical aperture greater than that possible using known conventional focusing techniques. By the method and apparatus of the invention, a wave of arbitrary wavefront profile and wavelength .lambda. is focused to a region of high amplitude having a spot size that approaches the fundamental limit of 0.25.lambda.. Imaging and patterning systems employing such a wave focusing method and apparatus provide ultra high resolution and ultra small feature sizes beyond the capabilities of systems utilizing conventional focusing elements.

Ultra high resolution wave focusing method and apparatus and systems

A method and apparatus are provided for performing non-invasive measurements, and in particular in vivo non-invasive measurements of the total body content of a particular element, or of the content of such elemetn in a particular body area, by use of resonant gamma ray detection. More particularly, gamma rays are generated at the resonant gamma absorption energy level for the element on which measurements are to be made and are passed through the portion of the patient's body for which measurements are to be made. Detected gamma rays passing through the patient's body may be utilized as an indication of the content of such element. The effect of non resonant gamma absorption may be subtracted by also passing gamma rays of non-resonant absorption energy through the same body part and utilizing detected gamma rays at this energy passing through the body to determine the non-resonant absorptions.

Method and apparatus for non-invasive measurements of selected body

Window constructions for use in particle accelerators to separate an evacuated accelerator beam chamber from a gas or liquid filled target area, which window structure enhances cooling of the foil covering the window opening and reduces stresses on the foil. For preferred embodiments, the window opening is shaped and dimensioned to provide high length-to-width aspect ratio and a rectangular shape with rounded corners. The openings should generally be as narrow as possible while still being wide enough to assure efficient transmission of the ion beam. Stresses in the foil is reduced by providing controlled bowing of the portions of the foil covering the window. This may be accomplished by providing some slack in the foil, at least in one dimension, but is preferably accomplished by pressing the foil between mating curved surfaces selectively extending from the edges of the window openings, resulting in the desired bow in the foil in the window area. With a rectangular opening, the bow is preferably a generally cylindrical bow about an axis parallel to the length dimension of the window. A generally spherical bow may also be utilized. A plurality of adjacent generally rectangular openings separated by struts are also utilized for some embodiments.

Window construction for a particle accelerator

A method of providing laser controlled real-time optics and optic systems for a laser beam or beams utilizing near resonance nonlinear dispersion in a collision dominated gaseous medium. Refractive optical elements may be provided that function as spherical or curved reflectors and refractive lens or prisms for expanding or contracting a laser beam or beams as well as providing gratings for providing partial or total reflection or deflection of a laser beam. The generation of a grating in accordance with the invention permits total deflection of large cross-section and powerful laser beams by the investment of a moderate amount of power. Real-time color holographic displays may also be provided and phase front aberrations caused by a laser amplifier may also be corrected.

Gaseous non linear dispersion laser beam control

In accordance with one embodiment of the present invention, a controlling laser beam at a first wavelength is introduced into an interferometer such that one half of it contains the aberrations of the laser beam to be controlled and the other half is and remains undistorted. The aforementioned two halves of the controlling laser beam are combined at the output of the interferometer and then, together with the laser beam to be controlled at a second wavelength is introduced collinearly into a gas cell or phase corrector. Upon combination or interference of the two halves of the controlling laser beam the phase-front aberrations are translated to intensity modulations across the cross section of the beam. Utilizing nonlinear dispersion in the gas cell in accordance with the invention, the intensity modulations across the controlling laser beam are transformed by nonlinear dispersion interaction into appropriate refractive index variations at the second wavelength which in turn causes corresponding phase changes across the phase front of the controlled laser beam. Adjustment of path length in the interferometer permits compensation of the aberrations in the controlled laser beam.

Method of and apparatus for correction of laser beam phase front

Gaseous lasers and their operation wherein during operation in the saturated regime Zeeman reorientation collisions do not occur rapidly compared to the rate at which population is transferred out of their upper lasing level and there exists a static magnetic field of predetermined minimum strength inside the lasing region that is preferably at, or substantially at, the magic angle (approximately 54.70) with respect to the predominate polarization of the laser light in the lasing cavity.

Growing community of inventors

Newton, MA, United States of America

Allen M Flusberg