Stephen E Ferguson

US Patent:

6904206, Jun 7, 2005

Filed:

Oct 15, 2003

Appl. No.:

10/686934

Inventors:

Yufei Bao - Norcross GA, US
Stephen K. Ferguson - Lawrenceville GA, US
Donald Q. Snyder - Marietta GA, US

Assignee:

Micron Optics, Inc. - Atlanta GA

International Classification:

G02B006/26

US Classification:

385 39, 385 28, 385 38, 385 79

Abstract:

Improved fiber Fabry-Perot (FFP) filter configurations are provided in which at least one of the mirror-ended fiber ends forming the FFP has a concave fiber core end. The mirror at that fiber core end is thus concave. The invention provides waferless FFP configurations in which the FFP cavity is an air-gap cavity formed by two highly reflective dielectric mirrors deposited directly on optical fiber ends. The air gap cavity can be tuned using various methods to tune the filter. Use of a concave mirror at the fiber core enables filters with improved performance characteristics: including very wide FSR (>12000 GHz), very high finesse (>5,000), and high glitch-free dynamic range (GFDR) (>40 dB). The invention also provides improved wafer-based FFP fixed and tunable filters that incorporate a concave mirror at a fiber core forming the FFP cavity and a fiber (SMF) waveguide within the cavity.

US Patent:

7063466, Jun 20, 2006

Filed:

Dec 18, 2003

Appl. No.:

10/742599

Inventors:

Stephen K. Ferguson - Lawrenceville GA, US

Assignee:

Micron Optics, Inc. - Atlanta GA

International Classification:

G02B 6/38

US Classification:

385 78, 385 58

Abstract:

The invention relates generally to optical interference filters and interferometers. Methods, devices and device components for fiber Fabry-Perot (FFP) filters and ferrule holders are provided. The invention provides ferrule holders for FFP filters capable of good radial and longitudinal alignment. An exemplary ferrule holder of the present invention is capable of substantially constraining the motion of a pair of ferrules in all directions except a direction parallel to the longitudinal axis, thereby allowing the resonance cavity of a FFP filter to be adjusted while maintaining good radial alignment. The invention further provides temperature compensated ferrule holders and FFP filters that are stable with respect to wavelength drift over a useful range of device operating conditions. In addition, the present invention provides ferrule holders and FFP filters which are particularly useful for monitoring ambient conditions and measuring physical properties and mechanical phenomena.

US Patent:

7856888, Dec 28, 2010

Filed:

Nov 15, 2007

Appl. No.:

11/940994

Inventors:

Stephen K. Ferguson - Lawrenceville GA, US

Assignee:

Micron Optics Inc. - Atlanta GA

International Classification:

G01L 1/24
G02B 6/00

US Classification:

73800, 385 13

Abstract:

The current invention relates to optical gages designed to measure strain on the surface of a test specimen. The gages of this invention is designed to be installed and used in a manner similar to conventional electronic foil strain gages, but to have the advantages of an all-optical gage. The gage of this invention is constructed to allow surface strain on the test specimen to be transferred to a length of optical fiber containing a fiber Bragg grating (FBG). As strain is applied to the fiber, the optical spectrum center wavelength reflected by the Bragg grating shifts in wavelength. This shift in wavelength can be converted directly to units of strain. The current invention provides a gage carrier design for use with fiber optic strain sensors comprising one or more FBGs which provide the benefits of a carrier for ease of handling and mounting without degrading gage performance. The gage carrier provides features that allow the FBG to be precisely positioned and securely bonded to the test specimen in a controlled manner. The carrier additionally provides fiber protection to the installed FBG.

US Patent:

20060285813, Dec 21, 2006

Filed:

Jun 12, 2006

Appl. No.:

11/452094

Inventors:

Stephen Ferguson - Lawrenceville GA, US

International Classification:

G02B 6/00

US Classification:

385138000, 385137000

Abstract:

The invention relates generally to optical sensors that impart physical strain to an optical fiber by varying the tension applied axially to the fiber, which causes a change in the optical property of the light transmitted through the fiber. Methods, devices and device components for optical sensors are provided. The invention provides fiber holders capable of retaining a fiber under tension with little or no creep even in high temperature, high humidity environments. An exemplary fiber holder of the present invention provides superior retaining properties over epoxy and other adhesives while preserving the tensile strength of the original fiber. The invention further provides fiber holders and sensors, which are particularly useful for monitoring ambient conditions and measuring physical properties and mechanical phenomena.

US Patent:

20070193362, Aug 23, 2007

Filed:

Feb 5, 2007

Appl. No.:

11/671325

Inventors:

Stephen Ferguson - Lawrenceville GA, US

International Classification:

G01L 1/24

US Classification:

073800000

Abstract:

Fiber optical gages that impart physical strain to an optical fiber by varying the tension applied axially to the fiber, which causes a change in the optical property of the light transmitted through the fiber. A gage carrier which provides the benefits of a metal carrier for ease of handling and mounting without degrading gage performance. At least a portion of the gage carrier is elastic with respect to expansion, compression or both along its longitudinal axis, thereby allowing for variation of the distance between the two points at which the gage carrier is attached to a test specimen. In a specific embodiment, the gage carrier functions as two independent rigid fiber fastening elements separated by a compliant or flexible member. The invention further provides fiber Bragg grating strain gages, which are particularly useful for monitoring ambient conditions and measuring physical properties and mechanical phenomena.

US Patent:

49800078, Dec 25, 1990

Filed:

Jul 14, 1989

Appl. No.:

7/379529

Inventors:

Stephen K. Ferguson - Buford GA

Assignee:

AT&T Bell Laboratories - Murray Hill NJ

International Classification:

B32B 500
G02B 606

US Classification:

156179

Abstract:

A group of loose cabled optical fibers (32-32) destined to be terminated by a multi-fiber connector device is first fabricated into an optical fiber ribbon (30). The optical fibers of the group are threaded through portions of an organizing shuttle (20) and brought into planar juxtaposition with each other by the cooperation of a curved surface (112) and a burnishing bar assembly (98). As the organinzing shuttle is caused to be moved along a track (42), the burnishing bar assembly causes the planar array of fibers to be embedded into an adhesive coating of a first binding tape (34) which is secured along the length of the track. In a preferred embodiment, a second tape (35) is applied over the fibers and the first tape. The ribbon is trimmed of excess longitudinal side portions of the binding tapes to provide a ribbon of desired width.

US Patent:

50768816, Dec 31, 1991

Filed:

Oct 1, 1990

Appl. No.:

7/591173

Inventors:

Stephen K. Ferguson - Buford GA

Assignee:

AT&T Bell Laboratories - Murray Hill NJ

International Classification:

B32B 500
G02B 606

US Classification:

156436

Abstract:

A group of loose cabled optical fibers (32--32) destined to be terminated by a multi-fiber connector device is first fabricated into an optical fiber ribbon (30). The optical fibers of the group are threaded through portions of an organizing shuttle (20) and brought into planar juxtaposition with each other by the cooperation of a curved surface (112) and a burnishing bar assembly (98). As the organizing shuttle is caused to be moved along a track (42), the burnishing bar assembly causes the planar array of fibers to be embedded into an adhesive coating of a first binding tape (34) which is secured along the length of the track. In a preferred embodiment, a second tape (35) is applied over the fibers and the first tape. The ribbon is trimmed of excess longitudinal side portions of the binding tapes to provide a ribbon of desired width.

US Patent:

20190258092, Aug 22, 2019

Filed:

May 2, 2019

Appl. No.:

16/401337

Inventors:

- Roanoke VA, US
Stephen K. FERGUSON - Atlanta GA, US

International Classification:

G02F 1/01
G08B 13/08

Abstract:

The present disclosure relates to optical switching devices and switch modules that are designed for long-term security monitoring of high-value infrastructure access entry points. Embodiments in accordance with the present disclosure include optical switches based on fiber-Bragg gratings whose operating wavelengths are based on the presence or absence of magnetic coupling between an embedded permanent magnet and an external element. By monitoring the spectral position of the operating wavelengths and/or the magnitude of a light signal at the operating wavelengths, the state of the magnetic coupling can be determined and used as an indicator of whether the security switch has been actuated.