Timothy M Pritchett

US Patent:

8159738, Apr 17, 2012

Filed:

Jun 16, 2010

Appl. No.:

12/816417

Inventors:

Robert C. Hoffman - Woodstock MD, US
Timothy Pritchett - Silver Spring MD, US

Assignee:

The United States of America as represented by the Secretary of the Army - Washington DC

International Classification:

G02F 1/03

US Classification:

359257, 359900

Abstract:

A large-aperture direct-view high-speed electro-optic shutter includes an electro-optic polymer material constructed to form a Pockels cell and an integrated photoconducting semiconductor switch. A chromophore-doped polymer material or chromophore copolymer, wherein the chromophore is oriented within the polymer material, exhibits a linear electro-optic effect when an electric field is applied to the device. In one embodiment, the polymer host material comprises one or more of a polycarbonate, amorphous polycarbonate, or polymethylmethacrylate polymer hosts. The optically active chromophore comprising one or more coumarin and coumarin derivatives, stilbene or tolane derivatives is incorporated within the polymer host, forming a guest-host polymer. In another embodiment, the chromophore is chemically bonded to the monomer that forms the polymer, resulting in an optically active copolymer. The electro-optic shutter device is then activated by incident light through the photoconducting semiconductor switch, rendering the Pockels cell to have an optical density of at least 3.

US Patent:

8363300, Jan 29, 2013

Filed:

Mar 7, 2012

Appl. No.:

13/413799

Inventors:

Robert C. Hoffman - Woodstock VA, US
Timothy Pritchett - Silver Spring MD, US

Assignee:

The United States of America as represented by the Secretary of the Army - Washington DC

International Classification:

G02F 1/03

US Classification:

359257, 359900

Abstract:

A large-aperture direct-view high-speed electro-optic shutter includes an electro-optic polymer material constructed to form a Pockels cell and an integrated photoconducting semiconductor switch. A chromophore-doped polymer material or chromophore copolymer, wherein the chromophore is oriented within the polymer material, exhibits a linear electro-optic effect when an electric field is applied to the device. In one embodiment, the polymer host material comprises one or more of a polycarbonate, amorphous polycarbonate, or polymethylmethacrylate polymer hosts. The optically active chromophore comprising one or more coumarin and coumarin derivatives, stilbene or tolane derivatives is incorporated within the polymer host, forming a guest-host polymer. In another embodiment, the chromophore is chemically bonded to the monomer that forms the polymer, resulting in an optically active copolymer. The electro-optic shutter device is then activated by incident light through the photoconducting semiconductor switch, rendering the Pockels cell to have an optical density of at least 3.

US Patent:

7751109, Jul 6, 2010

Filed:

Sep 14, 2006

Appl. No.:

11/527649

Inventors:

Robert C. Hoffman - Woodstock VA, US
Timothy Pritchett - Silver Spring MD, US

Assignee:

The United States of America as represented by the Secretary of the Army - Washington DC

International Classification:

G02F 1/03

US Classification:

359257

Abstract:

Various embodiments of an improved electro-optic shutter are disclosed. One embodiment comprises an electro-optic element, first and second polarizers, and a pair of electrodes. The electro-optic element has opposing transverse surfaces and operates as a half wave plate when a voltage V is applied to the element. The first and second polarizers are each disposed adjacent to one transverse surface of the electro-optic element. The first and second electro-optic element have parallel transmission axes. Each electrode is disposed on one of the transverse surfaces of the electro-optic element and has an electric field which is substantially uniform over the transverse extent of the electro-optic element.