David C Macpherson

US Patent:

6369898, Apr 9, 2002

Filed:

Jan 18, 2000

Appl. No.:

09/484773

Inventors:

Paul Phillip Van Saarloos - Karrinyup, AU
David Clyde MacPherson - Conifer CO

Assignee:

Q-Vis Limited

International Classification:

G01B 902

US Classification:

356497

Abstract:

Method and apparatus are provided for measuring the surface profile of a sample. The method and apparatus provide light from a light source through a beam splitter to form two split beams, direct the split beams onto a sample surface and a reference surface respectively, reflect the split beams back through the beam splitter, and direct the split beams towards an imaging system. A surface profiling apparatus for measuring the surface profile of the sample is also provided. The apparatus includes a light source for generating a source beam, beam splitting means positioned in the path of the source beam for splitting the source beam into split beams, a reference surface, a sample surface allowing the split beams to traverse separate paths and return to the beam splitting means, reference surface positioning means for positioning the reference surface, and viewing means for imaging combined beams. An apparatus for calibrating a laser for the ablation of a material including the surface profiling apparatus is also provided.

US Patent:

6396069, May 28, 2002

Filed:

Jun 25, 1999

Appl. No.:

09/344339

Inventors:

David C. MacPherson - Conifer CO 80433
Jon G. Dishler - Englewood CO 80111

International Classification:

G01N 2186

US Classification:

25055922, 350216, 356376

Abstract:

A surface contouring system may be provided with a topographer to measure the surface contours. The topographer may be a laser topographer that measures the surface contours using superheterodyne synthetic wavelength interferometry. The maximum vertical step size dictated by the limits of conventional laser interferometry may be increased by creating laser signals with synthetically-generated longer effective wavelengths. The topographer may perform sequential scans rapidly so that measurement feedback can be used to interactively control the shape of the surface being measured. The interferometer may use counter-rotating optical wedges to create a rotating, radially looping scan pattern that concentrates measurement density in the center portions of the target surface. Different embodiments of the topographer may be applied to diverse uses such as corneal ablation procedures, precision machining operations, and vibration analysis.

US Patent:

52852563, Feb 8, 1994

Filed:

Jul 28, 1992

Appl. No.:

7/921502

Inventors:

Loren D. Nelson - Evergreen CO
David C. MacPherson - Conifer CO

Assignee:

Ophir Corporation - Littleton CO

International Classification:

G01C 300

US Classification:

356342

Abstract:

Contrail detection aft of an aircraft is provided by a rear-looking ranging system carried by the aircraft. A randomly modulated laser beam is directed into a detection volume aft of the aircraft for scatter back toward a detector on the aircraft. Bistatic mounting of a laser and a telescope of the detector preclude sensing of the scattered beam forward of the detection volume. Processing of the detected scattered beam includes cross correlation and analysis to indicate the formation of the contrail aft of the aircraft.

US Patent:

56967780, Dec 9, 1997

Filed:

Oct 25, 1995

Appl. No.:

8/547809

Inventors:

David C. MacPherson - Conifer CO

Assignee:

Ophir Corporation - Littleton CO

International Classification:

H01S 330

US Classification:

372 4

Abstract:

Apparatus performs a method of generating one output laser pulses in a range of 2 to 5 microns using an intracavity feature. When a plurality of the output laser pulses are generated, a first output pulse may have any selected wavelength within the range and a second output pulse is temporally closely spaced relative to the first output pulse and may have a chosen wavelength differing from the selected wavelength. A pump laser cavity is provided with a tunable rod and an intracavity Raman device (in the pump cavity) to shift the wavelength of initial pump laser pulses. The intracavity Raman device generates radiation at first and second Stokes wavelengths, and the pulses at each wavelength are separated and are in separate paths for permitting separate operation thereon. The Raman device in the pump cavity increases the pump intensity inside the Raman cell and gives a much longer effective interaction length between the pump laser beam and the Raman medium. A first Stokes cavity for the first Raman shift overlaps the pump cavity such that the intensity in the first Stokes cavity is increased.

US Patent:

55838774, Dec 10, 1996

Filed:

May 9, 1995

Appl. No.:

8/437676

Inventors:

David C. MacPherson - Conifer CO
Loren D. Nelson - Evergreen CO
Martin J. O'Brien - Bailey CO

Assignee:

Ophir Corporation - Littleton CO

International Classification:

H01S 330

US Classification:

372 4

Abstract:

Apparatus performs a method of generating one or more output laser pulses in a range of 2 to 6 microns. When a plurality of the output laser pulses are generated, a first output pulse has any selected wavelength within the range and a second output pulse is temporally closely spaced relative to the first output pulse and has a chosen wavelength differing from the selected wavelength. An oscillator laser cavity is provided with a tunable oscillator rod capable of generating initial laser pulses within a range of from 750 to 1000 nm, and a tuning element is coupled to the rod. A flashlamp is operable to pump the rod. For two pulse operation, the flashlamp has a given duration. A Q-switch provides the initial laser pulses upon operation of the tuning element and the flashlamp. A Raman device coupled to the rod shifts the wavelength of such initial laser pulse into the range of from 2 to 6 microns to form the output laser pulse having a wavelength within the range. For multiple pulses, a controller causes the Q-switch to provide first and second ones of the initial laser pulses, spaced by a time interval less than the given duration.