James C Cowan

US Patent:

6608722, Aug 19, 2003

Filed:

Aug 1, 2001

Appl. No.:

09/920060

Inventors:

James Cowan - Lexington MA 02421
Kenneth A. Haines - Aptos CA 95003

International Classification:

G02B 530

US Classification:

359599, 359598, 359571, 359572

Abstract:

A diffuser is disclosed which transmits or reflects incident light into a specific range of angles. In a preferred embodiment, this light is uniformly scattered throughout a cone of angles. The diffuser consists of two parts. The first part diffracts or reflects light into a specific offset angle. The second part, in the preferred embodiment, uniformly scatters the light through a range of angles, which is centered on the offset angle. The diffusers have utility in applications such as screens for wrist watches, computers, calculators, and cell phones.

US Patent:

6707518, Mar 16, 2004

Filed:

Jul 12, 2000

Appl. No.:

09/615011

Inventors:

James J. Cowan - Lexington MA

Assignee:

CoHo Holdings, LLC - Burlington MA

International Classification:

G02F 11335

US Classification:

349113, 349107, 349160, 349198, 372 92, 372 99, 372105

Abstract:

Surface textures embossed in a substrate such as plastic include surface depressions or cones having equally-spaced, reflective terraced steps to support coherent reflections of incident light. A desired color or bandwidth of coherent reflected light off the terraced steps is produced by adjusting the index of refraction of a material in communication with the terraced steps of the substrate. Preferably, the index of refraction of each zone of terraced steps is controlled based on an applied electric field. Accordingly, light reflected from a plurality of controlled zones can be used to produce an image for an observer.

US Patent:

6791757, Sep 14, 2004

Filed:

Aug 6, 2002

Appl. No.:

10/213583

Inventors:

Douglas S. Hobbs - Lexington MA
James J. Cowan - Lexington MA

Assignee:

CoHo Holdings, LLC - Lexington MA

International Classification:

G02B 2700

US Classification:

359578, 359579, 359260, 359261, 359315, 359318, 359247, 349198

Abstract:

An apparatus for filtering electromagnetic waves and sensing deposition of chemical species, the apparatus having a substrate having a surface relief structure containing at least one dielectric body with physical dimensions smaller than the wavelength of the filtered electromagnetic waves, such structures repeated in a two dimensional array covering at least a portion of the surface of the first substrate. The apparatus may include one, two, or more such arrays, spaced from one another to create one or more cavities between the arrays.

US Patent:

6870624, Mar 22, 2005

Filed:

Oct 30, 2001

Appl. No.:

10/001069

Inventors:

Douglas S. Hobbs - Lexington MA, US
James J. Cowan - Lexington MA, US

Assignee:

Coho Holdings LLC - Lexington MA

International Classification:

G01N021/25
G01N021/47

US Classification:

356416, 356440, 422 8205

Abstract:

An apparatus for filtering electromagnetic waves, the apparatus comprising a substrate having a surface relief structure containing at least one dielectric body with physical dimensions smaller than the wavelength of the filtered electromagnetic waves, such structures repeated in a two dimensional array covering at least a portion of the surface of the first substrate. Also disclosed is a material sensor utilizing this apparatus.

US Patent:

6940665, Sep 6, 2005

Filed:

Aug 12, 2003

Appl. No.:

10/639552

Inventors:

James Cowan - Lexington MA, US
Kenneth A. Haines - Soquel CA, US

International Classification:

G02B013/20

US Classification:

359900, 359599, 359598

Abstract:

A diffuser is disclosed which transmits or reflects incident light into a specific range of angles. In a preferred embodiment, this light is uniformly scattered throughout a cone of angles. The diffuser consists of two parts. The first part diffracts or reflects light into a specific offset angle. The second part, in the preferred embodiment, uniformly scatters the light through a range of angles, which is centered on the offset angle. The diffusers have utility in applications such as screens for wrist watches, computers, calculators, and cell phones.

US Patent:

7304775, Dec 4, 2007

Filed:

Mar 2, 2001

Appl. No.:

09/798746

Inventors:

Douglas S. Hobbs - Lexington MA, US
James J. Cowan - Lexington MA, US

Assignee:

CoHo Holdings, LLC - Burlington MA

International Classification:

G03H 1/12
G03H 1/10
G03H 1/04

US Classification:

359 11, 359 10, 359 1, 359 35, 430 1

Abstract:

An interference lithography system is described that is capable of exposing high resolution patterns in photosensitive media and employing yield increasing active stabilization techniques needed in production environments. The inventive device utilizes a division-of-wavefront interference lithography configuration which divides a single large field size optical beam using one or more mirrors, and is actively stabilized with a subsystem employing; a phase modulator operating on each divided wavefront section; a novel feedback apparatus for observing the relative phase shifts between interfering wavefront sections; and a control system for holding the relative phase shifts constant. The present invention also includes; a method for shaping the illumination beam's intensity distribution for more efficient power utilization and greater feature size uniformity; a horizontal substrate loading configuration compatible with robotic handling; an automated pattern pitch calibration for simple, flexible system reconfiguration; a compact clean-room compatible superstructure for increased passive stability in high vibration manufacturing environments; and a method for optimizing the polarization state of the interfering beam sections in a multiple mirror system.

US Patent:

7460303, Dec 2, 2008

Filed:

Jul 26, 2007

Appl. No.:

11/828531

Inventors:

James Cowan - Lexington MA, US
Kenneth A. Haines - Soquel CA, US

Assignee:

Aztec Systems, Inc. - Lexington MA

International Classification:

G02B 5/02
G02B 13/20

US Classification:

359599, 359900

Abstract:

A diffuser is disclosed which transmits or reflects incident light into a specific range of angles. In a preferred embodiment, this light is uniformly scattered throughout a cone of angles. The diffuser consists of two parts. The first part diffracts or reflects light into a specific offset angle. The second part, in the preferred embodiment, uniformly scatters the light through a range of angles, which is centered on the offset angle. The diffusers have utility in applications such as screens for wrist watches, computers, calculators, and cell phones.

US Patent:

8254029, Aug 28, 2012

Filed:

Feb 14, 2008

Appl. No.:

12/031381

Inventors:

James J. Cowan - Lexington MA, US

Assignee:

Aztec Systems, Inc. - Lexington MA

International Classification:

G02B 5/18

US Classification:

359572, 359574, 359576

Abstract:

A surface relief structure includes a recording medium configured to be structurally modified when exposed to interfering and non-interfering portions of radiation beams, the structurally modified recording medium including, when viewed in a two-dimensional cross-section along one of the axes of the recording medium a plurality of equally spaced steps of fine-sized periodicity superimposed upon a plurality of deep depressions of substantially coarse-sized periodicity. The structurally modified recording medium is configured to produce in reflection single and multiple colors in a broad spectral range when illuminated by a source of light.