Richard A Fields

US Patent:

6515784, Feb 4, 2003

Filed:

Apr 24, 2001

Appl. No.:

09/840858

Inventors:

Bruce A. Ferguson - Redondo Beach CA
Richard A. Fields - Redondo Beach CA
Mark Kintis - Manhattan Beach CA
Elizabeth T. Kunkee - Manhattan Beach CA
Lawrence J. Lembo - Torrance CA
Stephen R. Perkins - Harbor City CA
David L. Rollins - Woodinville WA
Eric L. Upton - Bellevue WA

Assignee:

TRW Inc. - Redondo Beach CA

International Classification:

G02F 103

US Classification:

359244, 3593491, 250214 DC

Abstract:

An optical inverting system employs a first optical structure having an index of refraction that varies with the intensity of an incident beam and a second optical structure having a constant index of refraction, and forming an interface therebetween. An optical pulse stream is combined with a laser beam and the combined beam is applied to the first optical structure, impinging the interface at a predetermined angle of incidence. If the angle of incidence is less than a critical angle, the beam is refracted into the second optical structure. If the angle of incidence is greater than the critical angle, the beam is completely reflected at the interface. Thus the output of the second optical structure is an inversion, and the output of the first optical structure is a level shifted replica, of the optical digital pulse stream.

US Patent:

6529674, Mar 4, 2003

Filed:

Nov 29, 2001

Appl. No.:

09/998545

Inventors:

Richard A. Fields - Redondo Beach CA
Bruce A. Ferguson - Redondo Beach CA
Mark Kintis - Manhattan Beach CA
Elizabeth T. Kunkee - Manhattan Beach CA
Lawrence J. Lembo - Torrance CA
Stephen R. Perkins - Harbor City CA
David L. Rollins - Hawthorne CA
Eric L. Upton - Redondo Beach CA

Assignee:

TRW Inc. - Redondo Beach CA

International Classification:

G02B 600

US Classification:

385140

Abstract:

An optical device for use with an optical input beam comprising an optical thresholding device positioned along an optical path defined by the propagation direction of the optical input beam. If the combined intensity of the optical input beam and a control beam exceeds a threshold level, the optical beam passes through the thresholding device. Preferably, the optical thresholding device is a saturable absorber. When the device is configured as an optical comparator, the intensity of the optical input beam exceeds the threshold level and the thresholding device saturates and turns transparent so that the control beam passes through the thresholding device as an optical indicator beam. When the device is configured as an optical signal attenuator and the intensity of the optical input signal is negligible compared to that of the control beam, the combined intensity of the beams does not saturate the thresholding device.

US Patent:

6587256, Jul 1, 2003

Filed:

Jun 6, 2001

Appl. No.:

09/876017

Inventors:

James E. Leight - San Ramon CA
David L. Rollins - Woodinville WA
Richard A. Fields - Redondo Beach CA

Assignee:

Northrop Grumman Corporation - Los Angeles CA

International Classification:

G02F 129

US Classification:

359316, 359279, 359245, 385 2, 385 3

Abstract:

An RF combiner ( ) that combines a plurality of RF signals ( ) in the optical domain. The combiner ( ) includes a single optical source ( ) that generates an optical beam ( ). The optical beam ( ) is directed through a series of optical modulators ( ), such as optical phase modulators. Each modulator ( ) is responsive to an RF signal ( ) that is to be combined with the other RF signals ( ). Each modulator ( ) modulates the optical signal ( ) with the RF signal ( ) so that the modulations combine in an additive manner. A single optical phase demodulator ( ) is used to demodulate the composite phase modulated optical beam ( ) to generate the combined RF signal ( ). Suitable delay devices ( ) can be used between the optical modulators ( ), or the RF signals can be matched so that the RF signals combine in phase.

US Patent:

20020037148, Mar 28, 2002

Filed:

Nov 30, 2001

Appl. No.:

09/999556

Inventors:

Richard Fields - Redondo Beach CA, US
Bruce Ferguson - Redondo Beach CA, US
Mark Kintis - Manhattan Beach CA, US
Elizabeth Kunkee - Manhattan Beach CA, US
Lawrence Lembo - Torrance CA, US
Stephen Perkins - Harbor City CA, US
David Rollins - Hawthorne CA, US
Eric Upton - Redondo Beach CA, US

Assignee:

TRW Inc.

International Classification:

G02B006/26

US Classification:

385/140000

Abstract:

An optical device for use with an optical input beam comprises and optical thresholding device having a predetermined threshold level, and is positioned along an optical path defined by the propagation direction of the optical input beam. A source generates a control beam through the optical thresholding device, wherein if the combined intensity of the optical input beam and the control beam is large enough to exceed the threshold level of the thresholding device, the optical beam passes through he thresholding device. The thresholding device attenuates the optical beam as it passes therethrough. In a preferred embodiment, the optical thresholding device is a saturable absorber. When the device is configured as an optical comparator, the intensity of the optical input beam is large enough to exceed the threshold level of the thresholding device, the thresholding device saturates and turns transparent so that the control beam passes through the thresholding device as an optical indicator beam and the optical input beam passes through the thresholding device. When configured as an optical signal attenuator and the intensity of the optical input signal is negligible compared to that of the control beam the combined intensity of the optical input signal and the control beam do not saturate the thresholding device.

US Patent:

20020191251, Dec 19, 2002

Filed:

Jun 19, 2001

Appl. No.:

09/884831

Inventors:

Bruce Ferguson - Redondo Beach CA, US
Richard Fields - Redondo Beach CA, US
James Leight - San Ramon CA, US
Eric Upton - Bellevue WA, US
Robert Kasody - Long Beach CA, US

International Classification:

H04J014/02
H04J014/08

US Classification:

359/139000, 359/128000

Abstract:

An optical switching device that routes an optical data packet using an all optical architecture signal detection and switching system. The packet includes header bits, data bits and a reset bit. The header bits identify the switch state for routing the data packet and the specific routing information for distinct portions of the data packet. The header bits are transmitted at an optical carrier frequency different than the carrier frequency of the data bits. The reset bit resets the switch element processor to enable it to process and route the next data packet. The frequency of a particular header bit affects the index of refraction of a Bragg grating of a detector and the output of the detector is provided to a switch that determines the routing path of the packet. A return command resets the diffraction grating so that it does not affect subsequent header bits.

US Patent:

63273993, Dec 4, 2001

Filed:

Nov 22, 1999

Appl. No.:

9/444977

Inventors:

Richard A. Fields - Redondo Beach CA
Bruce A. Ferguson - Redondo Beach CA
Mark Kintis - Manhattan Beach CA
Elizabeth T. Kunkee - Manhattan Beach CA
Lawrence J. Lembo - Torrance CA
Stephen R. Perkins - Harbor City CA
David L. Rollins - Hawthorne CA
Eric L. Upton - Redondo Beach CA

Assignee:

TRW Inc. - Redondo Beach CA

International Classification:

G02B 626

US Classification:

385 19

Abstract:

An optical device for use with an optical input beam comprises and optical thresholding device having a predetermined threshold level, and is positioned along an optical path defined by the propagation direction of the optical input beam. A source generates a control beam through the optical thresholding device, wherein if the combined intensity of the optical input beam and the control beam is large enough to exceed the threshold level of the thresholding device, the optical beam passes through he thresholding device. The thresholding device attenuates the optical beam as it passes therethrough. In a preferred embodiment, the optical thresholding device is a saturable absorber. When the device is configured as an optical comparator, the intensity of the optical input beam is large enough to exceed the threshold level of the thresholding device, the thresholding device saturates and turns transparent so that the control beam passes through the thresholding device as an optical indicator beam and the optical input beam passes through the thresholding device. When configured as an optical signal attenuator and the intensity of the optical input signal is negligible compared to that of the control beam the combined intensity of the optical input signal and the control beam do not saturate the thresholding device.

US Patent:

6121907, Sep 19, 2000

Filed:

Aug 11, 1998

Appl. No.:

9/133038

Inventors:

Richard A. Fields - Redondo Beach CA
David L. Rollins - Hawthorne CA
Stephen R. Perkins - Redondo Beach CA
Eric L. Upton - Redondo Beach CA
Elizabeth T. Kunkee - Manhattan Beach CA
Lawrence J. Lembo - Torrance CA
Juan C. Carillo - Torrance CA
Mark Kintis - Manhattan Beach CA

Assignee:

TRW Inc. - Redondo Beach CA

International Classification:

H03M 100

US Classification:

341137

Abstract:

An optical analog-to-digital converter (10) which fully operates in the optical domain and utilizes an upward-folding successive approximation approach for conversion. The converter (10) includes a plurality of optical stages (14, 16, 18) where each stage (14, 16, 18) generates a digital bit. Each stage (14, 16, 18) includes an optical threshold switch (30, 56, 78) that sets the bit high when the switch (30, 56, 78) is closed. When a sample amplitude of the analog signal is compared to a threshold value and found to exceed the threshold value, the bit is set to "high" and the sample is passed directly onto the next stage (14, 16, 18). If the sample amplitude is found to be less than the threshold value, the bit is set to "low" and an intensity equal to the maximum signal intensity minus the threshold intensity is added to the sample amplitude. Each successive stage (14, 16, 18) compares the normalized signal sample to thresholds growing closer and closer to the maximum signal intensity. Multiple bits can be obtained by cascading stages.

US Patent:

62921193, Sep 18, 2001

Filed:

Jun 30, 1999

Appl. No.:

9/345295

Inventors:

Juan C. Carillo - Torrance CA
Bruce A. Ferguson - Redondo Beach CA
Richard A. Fields - Redondo Beach CA
Mark Kintis - Manhattan Beach CA
Elizabeth T. Kunkee - Manhattan Beach CA
Lawrence J. Lembo - Torrance CA
Stephen R. Perkins - Redondo Beach CA
David L. Rollins - Hawthorne CA
Eric L. Upton - Redondo Beach CA

Assignee:

TRW Inc. - Redondo Beach CA

International Classification:

H03M 100

US Classification:

341137

Abstract:

An optical analog-to-digital converter (10) that makes use of a downward-folding successive approximation conversion scheme that employs subtraction of optical signals. A pulsed optical signal (20) to be converted is applied as an input to each of a plurality of converter channels (12, 14, 16, 18), where each channel (12, 14, 16, 18) outputs one of the bits of the digital output of the converter (10). The input signal (20) to each channel (12, 14, 16, 18) is sent to a thresholding device (24, 40, 60, 80) that determines whether the intensity of the signal is greater than or less than a predetermined threshold value. The first channel thresholding device (24) compares the input signal (20) to a threshold value that is one-half of a known maximum intensity. Subsequent channel thresholding devices (40, 60, 80) compare the input signal to a threshold value that is one-half of the intensity used in the previous channel in a downward-folding scheme. If the intensity of the input signal (20) is greater than the threshold value in a particular channel (12, 14, 16, 18), then that threshold value is subtracted from the input signal (20) in each of the successive channels before being applied to the thresholding device (40, 60, 80) in that channel (14, 16, 18).