Rudolf N Oldenbourg

Author:

Rudolf Oldenbourg

ISBN #:

3765419036

US Patent:

6501548, Dec 31, 2002

Filed:

Jun 18, 2001

Appl. No.:

09/883602

Inventors:

Rudolf Oldenbourg - Falmouth MA

Assignee:

Cambridge Research Instrumentation Inc. - Woburn MA

International Classification:

G01J 400

US Classification:

356368, 356366, 356367

Abstract:

A method for measuring sample retardance in the presence of spurious background retardance contributed by optical components such as strained lenses in the measurement system, which is accurate where there is a retardance in excess of 15 degrees in the sample, the background, or the combination thereof. The method can be applied to imaging systems that record polarized light intensities for obtaining retardance magnitude and angular orientation values at all points in a scene simultaneously. The system first takes images that record the apparent slow axis orientation and the apparent retardance of the sample at all image points. Then the sample is removed and images are taken that record the background retardance alone. Algorithms for minimizing the effect of the background retardance on the measured sample retardance make use of the separately measured polarized light intensities of sample with background and of the background alone. The algorithms can be applied to each picture element simultaneously and do not make use of spatial relationships or distributions within the sample.

US Patent:

6924893, Aug 2, 2005

Filed:

May 12, 2003

Appl. No.:

10/435929

Inventors:

Rudolf Oldenbourg - Falmouth MA, US
Mykhailo Shribak - Woods Hole MA, US
Clifford C. Hoyt - Wellesley MA, US
Peter Török - London, GB

Assignee:

Marine Biological Laboratory - Woods Hole MA

International Classification:

G01J004/00

US Classification:

356369

Abstract:

A microscope system for determining optical properties of a specimen includes a source of polarized light, a detector for detecting the intensity of light incident thereon, an optical path extending from the source to the detector, a condenser for providing light from the source to the specimen, an objective for receiving light from the specimen, a support for mounting the specimen, a sectored variable retarder mounted in the optical path, and a polarized light analyzer mounted in the path between the sectored variable retarder and the detector. The variable retarder has a multiple sectors. Each sector is individually addressable by a control signal that affects the light retardation characteristics of the sector.

US Patent:

7079247, Jul 18, 2006

Filed:

Jul 8, 2003

Appl. No.:

10/616328

Inventors:

Mykhailo Shribak - Woods Hole MA, US
Rudolf Oldenbourg - Falmouth MA, US
Paul J. Cronin - Charlestown MA, US
Clifford C. Hoyt - Somerville MA, US
Peter J. Miller - Newburyport MA, US

Assignee:

Marine Biological Laboratory - Woods Hole MA

International Classification:

G01J 4/00

US Classification:

356364

Abstract:

The invention provides a highly sensitive measurement of retardance and slow axis orientation, accurately and instantaneously, across a full two-dimensional image. There are no moving parts and there need not be any electro-optic tuning as part of the measurement. It is ideally adapted to real-time imaging and is well-suited to use with biological and medical samples, including visualizing structures in oocytes. The invention splits a light beam into several beams, which are analyzed using elliptical polarizers and the resultant intensity is measured. It can be constructed using a single pixilated detector, or several detectors, to achieve high spatial resolution when this is desired.

US Patent:

7202950, Apr 10, 2007

Filed:

Jul 8, 2003

Appl. No.:

10/616080

Inventors:

Mykhailo Shribak - Woods Hole MA, US
Rudolf Oldenbourg - Falmouth MA, US

Assignee:

Marine Biological Laboratory - Woods Hole MA

International Classification:

G01J 4/00

US Classification:

356364

Abstract:

In an apparatus and method for measuring retardance and slow axis azimuth in sample specimens, a sample is illuminated by circularly polarized monochromatic light which is then analyzed by an elliptical analyzer at different settings. In another embodiment, light conditioned by an elliptical polarizer at various settings illuminates a specimen and the beam exiting the sample is analyzed by a circular analyzer. The elliptical analyzer/polarizer may have selectable ellipticity and azimuth angle, including in some cases a setting of circular polarization. Background images obtained with selected settings of the elliptical analyzer/polarizer, but without the sample present, are used in some embodiments to improve the measurement.

US Patent:

7239388, Jul 3, 2007

Filed:

Jan 17, 2006

Appl. No.:

11/333621

Inventors:

Mykhailo Shribak - Woods Hole MA, US
Rudolf Oldenbourg - Falmouth MA, US

Assignee:

Marine Biological Laboratory - Woods Hole MA

International Classification:

G01J 4/00

US Classification:

356364

Abstract:

In an apparatus and method for measuring retardance and slow axis azimuth in sample specimens, a sample is illuminated by circularly polarized monochromatic light which is then analyzed by an elliptical analyzer at different settings. In another embodiment, light conditioned by an elliptical polarizer at various settings illuminates a specimen and the beam exiting the sample is analyzed by a circular analyzer. The elliptical analyzer/polarizer may have selectable ellipticity and azimuth angle, including in some cases a setting of circular polarization. Background images obtained with selected settings of the elliptical analyzer/polarizer, but without the sample present, are used in some embodiments to improve the measurement.

US Patent:

7372567, May 13, 2008

Filed:

Mar 8, 2007

Appl. No.:

11/715750

Inventors:

Mykhailo Shribak - Woods Hole MA, US
Rudolf Oldenbourg - Falmouth MA, US

Assignee:

Marine Biological Laboratory - Woods Hole MA

International Classification:

G01J 4/00

US Classification:

356364

Abstract:

In an apparatus and method for measuring parameters related to retardance and slow axis azimuth in sample specimens, a sample is illuminated by circularly polarized monochromatic light which is then analyzed by an elliptical analyzer at different settings. In another embodiment, light conditioned by an elliptical polarizer at various settings illuminates a specimen and the beam exiting the sample is analyzed by a circular analyzer. Background images obtained with selected settings of the elliptical analyzer/polarizer, but without the sample present. Algorithms are described which employ two specimen images with elliptical settings and three or two background images; or which employ three specimen images with elliptical settings; or which employ four specimen images with elliptical settings without an extinction setting; or which employ five specimen images with four elliptical settings and one extinction setting. These algorithms allow one to variously optimize measurements for speed, sensitivity, and accuracy.

US Patent:

55217052, May 28, 1996

Filed:

May 12, 1994

Appl. No.:

8/241842

Inventors:

Rudolf Oldenbourg - Cataumet MA
Guang Mei - East Falmouth MA

International Classification:

G01N 2121

US Classification:

356368

Abstract:

A method for determining polarization properties of light from an object uses a detector for detecting the intensity of light incident thereon. A pair of variable retarders are positioned in the optical path with their slow optical axes at a 45. degree. angle to each other, and a polarized light analyzer is also placed in the optical path between the light retarders and the detector. For each of the light retarders, a base retardance level is determined. The base retardance level is such that when each of the light retarders is set at the base retardance thereof and light from an object is circularly polarized, the light analyzer will cause substantial extinction of light from the object that traverses the analyzer and the intensity of light from the object incident on the detector will be substantially zero. Then, the retardance of the light retarders is set at a first retardance level in which the retardance of at least one of said retarders is different from the base retardance thereof and the intensity of light incident on said detector when said light retarders are set at the first retardance level is determined. This procedure is repeated with the retardance of the light retarders set at a second, and different retardance level.