Robert G Swartz

US Patent:

20120185437, Jul 19, 2012

Filed:

Nov 15, 2011

Appl. No.:

13/297262

Inventors:

Elan Pavlov - Cambridge MA, US
Stephen Ness - San Francisco CA, US
Roger Critchlow - Santa Fe NM, US
Robert Swartz - Highland Park IL, US
Timothy S. Murphy - Milwaukee WI, US
Ronald Lachman - Northbrook IL, US

International Classification:

G06F 12/16
G06F 17/30

US Classification:

707652, 707E17005

Abstract:

A distributed heterogeneous or homogeneous file storage system divides logical responsibility for data from actual control of the data by using separate file and storage managers. Each file manager provides access to stored files and stores metadata associated with each of the files for which it is responsible. A file manager control component allocates responsibilities among file managers, assigns management responsibilities for individual files, and maintains a record of which files are assigned to each manager. Each storage manager is responsible for managing storage of files on data storage devices and maintains a record of the location of each stored file. A storage manager control component allocates responsibilities among storage managers, assigns responsibilities for individual files, and maintains a record of which files and storage devices are assigned to each manager. A client provides user access, initiates actions within the system, and implements a redundant data recovery and reconstruction scheme.

US Patent:

46808108, Jul 14, 1987

Filed:

Jun 28, 1985

Appl. No.:

6/749746

Inventors:

Robert G. Swartz - Highlands NJ

Assignee:

American Telephone and Telegraph Company, AT&T Bell Labs - Murray Hill NJ

International Classification:

H04B 900

US Classification:

455609

Abstract:

The novel technique for stabilizing an electronic device, e. g. , a semiconductor laser, is disclosed. The technique can advantageously be used to stabilize the bias current of such a laser at or near the lasing threshold of the device. A preferred application of thus stabilized lasers is in optical communication systems. The inventive technique comprises determination of a derivative of a variable characteristic of the device operation, e. g. , the voltage across a laser, with respect to a parameter, e. g. , the laser bias current. The derivative is determined by a novel method. For the particular case of laser bias stabilization, the method comprises injecting one or more nonsinusoidal ac current components into the laser, and phase-sensitivity detecting the voltage changes at the ac frequencies. The method can, in principle, be used to determine derivatives of arbitrarily high order. A circuit capable of determining the second, third and fourth derivatives of the voltage as a function of bias current is disclosed.

US Patent:

44281110, Jan 31, 1984

Filed:

Dec 7, 1981

Appl. No.:

6/327790

Inventors:

Robert G. Swartz - Highlands NJ

Assignee:

Bell Telephone Laboratories, Incorporated - Murray Hill NJ

International Classification:

H01L 21203
H01L 21302

US Classification:

29576E

Abstract:

A process for fabricating a high speed bipolar transistor is described wherein the collector, base and emitter layers are first grown using molecular beam epitaxy (MBE). A mesa etch is performed to isolate a base-emitter region, and a contact layer is grown using MBE over this isolated region to make contact with the thin base layer. The contact layer is selectively etched to expose the emitter layer, and metal is deposited to fabricate emitter, base and collector contacts.

US Patent:

51914620, Mar 2, 1993

Filed:

May 11, 1990

Appl. No.:

7/534623

Inventors:

Richard D. Gitlin - Little Silver NJ
Sanjay Kasturia - Red Bank NJ
Robert G. Swartz - Tinton Falls NJ
Jack H. Winters - Middletown NJ

Assignee:

AT&T Bell Laboratories - Murray Hill NJ

International Classification:

H04B 1006

US Classification:

359189

Abstract:

Signal distortion in fiber optic systems is compensated for by forming decisions as to the transmitted information as a joint function of the received signal and of a feedback signal. The latter, in turn, is a function of decisions made for at least one signal transmitted over the fiber. The feedback signal determines the value of a threshold to which the received signal is compared in order to generate the decisions.

US Patent:

43859461, May 31, 1983

Filed:

Jun 19, 1981

Appl. No.:

6/275418

Inventors:

Sean N. Finegan - Aberdeen NJ
James H. McFee - Colts Neck NJ
Robert G. Swartz - Highlands NJ
Alexander M. Voshchenkov - Freehold NJ

Assignee:

Bell Telephone Laboratories, Incorporated - Murray Hill NJ

International Classification:

H01L 21203
H01L 21263

US Classification:

148175

Abstract:

A molecular beam epitaxial method of fabricating a semiconductor device is disclosed wherein the dopant is implanted by establishing a plasma containing ions of the dopant and the ions are coupled through a drift chamber to impinge on the growing substrate surface. The plasma formed in the ion gun has ions of boron and arsenic and therefore the dopants selected for implantation can be determined by setting a mass filter present in the ion gun. A change to the dopant of the opposite conductivity type can be accomplished in seconds by simply readjusting the mass filter in the ion gun.

US Patent:

44928521, Jan 8, 1985

Filed:

Feb 11, 1983

Appl. No.:

6/465800

Inventors:

Sean N. Finegan - Aberdeen NJ
James H. McFee - East Windsor NJ
Robert G. Swartz - Highlands NJ

Assignee:

AT&T Bell Laboratories - Murray Hill NJ

International Classification:

H05B 100
H01L 2120

US Classification:

219405

Abstract:

A substrate heating arrangement suitable for use in ultra-high vacuum MBE includes a filament responsive to a DC current for generating thermal energy, a metallic enclosure surrounding the filament and having an aperture at one end thereof, an intermediate semiconductor substrate parallel to and separated from a semiconductor growth substrate, and a substrate support mounted to the enclosure capable of holding the substrates in the prescribed relationship. The intermediate semiconductor substrate regulates the temperature on the surface of the semiconductor growth substrate to be less than or equal to a fixed temperature (approximately 1100. degree. C. for silicon) regardless of the DC current applied to the filament.

US Patent:

45395543, Sep 3, 1985

Filed:

Oct 18, 1982

Appl. No.:

6/434876

Inventors:

John F. Jarvis - Fair Haven NJ
Robert G. Swartz - Highlands NJ
Bruce A. Wooley - Tinton Falls NJ

Assignee:

AT&T Bell Laboratories - Murray Hill NJ

International Classification:

G06F 302
H01L 4108

US Classification:

345365A

Abstract:

An integrated array of pressure transducers capable of producing an analog output voltage representative of the applied pressure is proposed. The individual transducing elements (16) are defined by a three-layer structure including a thin layer of piezoelectric material (10) disposed between a reference potential plate (12) and a plurality of electrodes (15) contained in a silicon substrate (14). A force applied to a localized portion of the reference plate will cause a deflection of the piezoelectric material towards the electrodes on the substrate, inducing a capacitive charge on the electrode in the localized area. This capacitance is stores at a node A associated with the transducing element, and may be interrogated by a sensing circuit (18) located in the silicon substrate. Since the induced charge is directly proportional to the applied force, a measurement of the output voltage from node A will yield a direct indication of the localized force applied to the sensor.

US Patent:

43597734, Nov 16, 1982

Filed:

Jul 7, 1980

Appl. No.:

6/166045

Inventors:

Robert G. Swartz - Highlands NJ
Ping K. Tien - Chatham Township, Morris County NJ
Bruce A. Wooley - Tinton Falls NJ

Assignee:

Bell Telephone Laboratories, Incorporated - Murray Hill NJ

International Classification:

H01S 310

US Classification:

372 26

Abstract:

A plurality of semiconductor lasers (431-434) and a photodetector (120) are mounted on a silicon substrate (100) having an integrated circuit (101) fabricated therein. The integrated circuit includes a biasing circuit (405) for establishing a threshold current level that is dependent on the output of the photodetector and a modulator circuit (404) for providing a modulation current that is dependent on the digital values in an input signal. A semiconductor switch (406) selects only one of the plurality of semiconductor lasers for activation by the biasing and modulator circuits. The integrated circuit also includes a circuit (408) that operates the semiconductor switch so as to selectively activate a different one of the plurality of semiconductor lasers in response to either a predetermined output from said photodetector or in response to an external supervisory signal.