Abstract: Sol-gel processing of a silica glass body is facilitated by rapid drying. The body, having been heated to a temperature of about 200.degree. C. in a hermetically sealed vessel, is vented while reducing temperature. Termination of drying coincides with reduction to atmospheric pressure.
Abstract: Stability of a pump laser for activating an erbium amplifier is enhanced by a grating which results in laser operation in the coherence collapse regime.
Type:
Grant
Filed:
January 6, 1994
Date of Patent:
October 8, 1996
Assignee:
AT&T Corp.
Inventors:
Turan Erdogan, Clinton R. Giles, Victor Mizrahi
Abstract: Heating a wet colloidal gel body in an autoclave above its 1-atmosphere boiling point, under rigorously defined conditions, avoids shrinkage during subsequent drying. As a consequence, drying rates may be increased, and handling care becomes less critical.
Abstract: Critical placement and lengths of dispersion-compensating fiber maximize capacity in upgraded in-ground optical fiber communication systems. Higher per-channel bit rates in single-channel systems and in WDM systems are permitted.
Type:
Grant
Filed:
March 1, 1995
Date of Patent:
September 24, 1996
Assignee:
Lucent Technologies Inc.
Inventors:
Andrew R. Chraplyvy, Fabrizio Forghieri, Alan H. Gnauck, Robert W. Tkach
Abstract: Wavelength Division Multiplexed channels in optical fiber communications systems have channel-to-channel frequency spacings which prevent substantial coincidence of 4-wave mixing products with channel carriers. As a consequence, system capacity is increased.
Type:
Grant
Filed:
July 13, 1995
Date of Patent:
August 13, 1996
Assignee:
AT&T Corp.
Inventors:
Andrew R. Chraplyvy, Fabrizio Forghieri, Robert W. Tkach
Abstract: Rare-earth doped single-crystal amplifiers serve to simultaneously amplify member channels of an optical fiber WDM system. A tailored amplification bandwidth sufficient for this purpose is the result of a variety of "defects" which after the local crystal field as "seen" by dopant ions.
Type:
Grant
Filed:
January 24, 1995
Date of Patent:
July 9, 1996
Assignee:
AT&T Corp.
Inventors:
Tasoltan T. Basiev, Paul M. Bridenbaugh, Gordon A. Thomas
Abstract: The operating principle of the attenuated phase mask is incorporated in a reflecting structure for use with extreme ultraviolet radiation. A working projection-reduction system for use with 0.18 .mu.m and smaller features combines the mask with all-reflecting optics.
Type:
Grant
Filed:
October 20, 1994
Date of Patent:
May 28, 1996
Assignee:
AT&T Corp.
Inventors:
Donald M. Tennant, Donald L. White, Obert R. Wood, II
Abstract: The fabrication of integrated circuit devices built to design rules of 0.18 .mu.m and below uses patterning radiation in the EUV spectrum. Optimized processing conditions take advantage of independently developed EUV characteristics such as short resist absorption lengths.
Type:
Grant
Filed:
October 20, 1994
Date of Patent:
April 23, 1996
Assignee:
AT&T Corp.
Inventors:
Donald M. Tennant, Donald L. White, Obert R. Wood, II
Abstract: A single crystal fluorescent material is used in the conversion of a short wavelength image. Conversion to a long wavelength image in the visible spectrum permits use of conventional glass optics for visual observation of UV and x-ray images. An illustrative use is in inspection of masks designed for use in fabrication of large scale integrated circuitry built to submicron design rules.
Type:
Grant
Filed:
January 5, 1994
Date of Patent:
March 12, 1996
Assignee:
AT&T Corp.
Inventors:
Bruno M. La Fontaine, Donald L. White, Obert R. Wood, II
Abstract: A 980 nm pump, for use with an erbium-doped fiber amplifier, provides redundancy together with simultaneous pumping, both co-propagating and counter-propagating, relative to 1550 nm signal, without need for an isolator.
Type:
Grant
Filed:
November 28, 1994
Date of Patent:
October 10, 1995
Assignee:
AT&T Corp.
Inventors:
Gloria R. Jacobovitz-Veselka, Kenneth L. Walker
Abstract: Devices built to design rules .ltoreq.0.25 .mu.m are pattern delineated by use of synchrotron-emitted x-ray radiation using a condenser which collects over a collection arc of at least 100 mrad. Condenser designs provide for processing of collected radiation to tailor characteristics such as direction and divergence. Pattern delineation by proximity printing as well as by projection printing is described. Forms of projection printing include reduction ringfield projection as by 5:1 mask:image reduction.
Abstract: Optical fiber and cable performance are assured by a category of UV-cured polyurethane acrylates. Low cost is the consequence of use of the polycarbonate oligomer. Good performance and long life are ascribed to other ingredients of the coatings. Dependence on the hindered phenols for antioxidant protection assures sufficient protection for these inherently stable materials without incurring fiber damage found to result from use of hindered amine antioxidants.
Type:
Grant
Filed:
September 30, 1993
Date of Patent:
March 28, 1995
Assignee:
AT&T Bell Laboratories
Inventors:
Lee L. Blyler, Jr., Darryl L. Brownlow, Daryl Inniss, James R. Petisce, Lloyd Shepherd, Carl R. Taylor
Abstract: Lowered cost fabrication including preparation of large bodies of void-free, high-silica glass, depends upon gellation of an aqueous sol of colloidal silica particles, followed by drying and firing of such gel. Freedom from cracks in the dried gel is the consequence of included polymeric material which wets the particles. The polymeric material is removed by thermal decomposition attended upon temperature attained in firing.
Type:
Grant
Filed:
August 31, 1993
Date of Patent:
January 3, 1995
Assignee:
AT&T Corp.
Inventors:
Edwin A. Chandross, Debra A. Fleming, David W. Johnson, Jr., John B. MacChesney, Frederick W. Walz, Jr.
Abstract: Fabrication of 0.25 gm design rule or smaller devices on chips, that may attain levels of 256 megabit or higher depends upon lithographic patterning by use of accelerated charged particle beams. Fabrication is expedited by acceleration values resulting in deBroglie wavelengths at least in order of magnitude smaller than such design rule to permit cost saving both in fabricating apparatus and resulting devices. Most importantly, such wavelength values permit significant variation in spatial angle of incidence of beam to wafer to permit both large instantaneous exposure areas and in temporal angle of incidence to expedite beam scanning as emitted from a fixed particle source.
Abstract: Bent sol-gel produced tubing is straightened by drawing, with tensile force and operating temperature to result in minimal plastic flow, so that size reduction is small. The method is usefully applied to reject recovery in the preparation of overclad tubes, which as encompassing closely-fitting core rods, form the composite preform from which optical fiber is drawn.
Abstract: Incidence of breakage in optical fiber drawn from sol-gel produced preforms is reduced by treatment of the still-porous glass by use of a chlorine-containing, oxygen-free gas mixture. Improved satisfaction of proof-rest requirements to at least 100 kpsi is assured by size reduction of unassimilated discrete particles in the fiber.
Abstract: Lasing threshold for a whispering mode laser is reduced by appropriate placement of a reflector. A reflector parallel to, and within a wavelength distance of, the disk decreases radiation loss due to imperfect internal reflection. Enhancement is calculable on the basis of destructive interference between reflected and direct radiation.
Type:
Grant
Filed:
April 14, 1993
Date of Patent:
September 27, 1994
Assignee:
AT&T Bell Laboratories
Inventors:
Louis D. Lanzerotti, Samuel L. McCall, Bernard Yurke
Abstract: Optical fiber drawn from preforms including sol-gel-derived glass is found to contain small refractory particles of the order of a micron in size. These particles initiate fiber breaks with the result that fiber may not meet proof-test tensile strength requirements. An effective separation method relies upon density and/or size difference from suspended sol particles for separation in the ungelled sol. A preferred separation procedure is centrifugation.
Type:
Grant
Filed:
March 11, 1993
Date of Patent:
September 6, 1994
Assignee:
AT&T Bell Laboratories
Inventors:
Suhas D. Bhandarkar, Harish C. Chandan, David W. Johnson, Jr., John B. MacChesney
Abstract: Device for electromagnetic emission depends on total internal reflection-on whispering gallery mode cavitation about the periphery of a disk-shaped element of sub-wavelength thickness. As a laser, operating above threshold, the design is alternative to that of the Surface Emitting Laser for integration in integrated circuitry-either all-optic or electro-optic. Operating below threshold, it may serve as a Light Emitting Diode. The same operational considerations-based on improved efficacy for whispering gallery mode devices as due to relevant dimension/s of sub-wavelength thickness-is of consequence for a category of devices serving other than as simple emitters. Such three port devices may serve as switches, modulators, etc.
Abstract: Submicron device fabrication entailing ringfield x-ray pattern delineation is facilitated by use of a condenser including a faceted collector lens. The collector lens is constituted of paired facets, symmetrically placed about an axis of a laser-pumped plasma source. Each of the members of a pair produce an image of the entire illumination field so that inhomogeneities in illumination intensity are compensated within each composite image as produced by a particular pair.