Steven T Bowman

US Patent:

6370172, Apr 9, 2002

Filed:

Dec 27, 1999

Appl. No.:

09/472012

Inventors:

Steven R. Bowman - Davidsonville MD

Assignee:

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

International Classification:

H01S 304

US Classification:

372 34, 372 40, 372 41, 372 70

Abstract:

A method for selecting laser and pump frequencies for a quasi-two level solid state laser with a selected laser host and operating the laser with the selected laser and pump frequencies, the host having a fluorescence probablility P( ) over a frequency range from to , has the steps: (a) determining for the laser host, a power weighted average fluorescence frequency given by (b) selecting an output frequency for the quasi-two level solid state laser to satisfy the expression , and tuning the laser for laser emission at the ; and (c) selecting a pump frequency for the quasi-two level solid state laser to satisfy the expression , and optically pumping the laser host with a laser pump to produce laser emission at the. This invention will provide athermal laser operation.

US Patent:

7964158, Jun 21, 2011

Filed:

May 11, 2007

Appl. No.:

11/747564

Inventors:

Nicholas J. Condon - Greenbelt MD, US
Steven R. Bowman - Edgewater MD, US
Shawn P. O'Connor - Arlington VA, US

Assignee:

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

International Classification:

B01D 9/00

US Classification:

422243, 4222451, 117200

Abstract:

A method and apparatus for growing a single crystal KPbClmaterial using a device including a plug including an axis. The plug includes a first portion defining a cylindrical hole about the axis. The plug includes a second portion defining a first conical hole about the axis. The first conical hole has a first angle. The plug includes a third portion defining a second conical hole about the axis. The second conical hole has a second angle opposite in sign relative to the first angle. The plug includes a fourth portion defining a third conical hole about the axis. The third conical hole has a third angle, the third angle having a same sign as the second angle and being greater than the second angle. The device further includes an ampoule including the plug fused therein.

US Patent:

20110168080, Jul 14, 2011

Filed:

Mar 17, 2011

Appl. No.:

13/049962

Inventors:

NICHOLAS J. CONDON - Greenbelt MD, US
Steven R. Bowman - Edgewater MD, US
Shawn P. O'Connor - Dunkirk VA, US

International Classification:

C30B 11/02

US Classification:

117 3, 117206

Abstract:

A method and apparatus for growing a single crystal KbClmaterial in a growth furnace comprising an upper zone set at 480 C. A single crystal KbClmaterial is grown from a single KbClgrain until a eutectic point is reached. The upper zone is cooled at 1/hour to 380 C. The single crystal KbClmaterial is annealed. The single crystal KbClmaterial is cooled at 10/hour to room temperature. Optionally, the method further includes loading an ampoule with KbClpowder, the ampoule including a plug, which includes a seeding well and an aperture. The KbClpowder is melted, thereby generating a melt. The melt is frozen to capture a polycrystalline KbClmaterial in the seeding well, thereby generating a polycrystalline KbClseed. The ampoule is loaded into the growth furnace. The polycrystalline KbClmaterial is melted except for the polycrystalline KbClseed, the polycrystalline KbClseed including the single KbClgrain. The polycrystalline KbClmaterial is grown until the single KbClgrain is isolated by the aperture.

US Patent:

20130083402, Apr 4, 2013

Filed:

Sep 28, 2012

Appl. No.:

13/629648

Inventors:

Jasbinder S. Sanghera - Ashburn VA, US
Catalin M. Florea - Washington DC, US
Leslie Brandon Shaw - Woodbridge VA, US
Lynda E. Busse - Alexandria VA, US
Ishwar D. Aggarwal - Charlotte NC, US
Steven R. Bowman - Edgewater MD, US

International Classification:

G02B 1/11
B23P 17/00

US Classification:

359601, 29592

Abstract:

An optical system having two or more different optical elements with a corresponding interface between the optical elements. At least one of the optical elements has an anti-reflective structure that is transferred to the interface between two optical elements, typically by embossing. Also disclosed is the related method for making the optical system.

US Patent:

20130119308, May 16, 2013

Filed:

Nov 13, 2012

Appl. No.:

13/675890

Inventors:

Nicholas J. Condon - Silver Spring MD, US
Steven R. Bowman - Edgewater MD, US
Shawn P. O'Connor - Dunkirk VA, US

International Classification:

C01D 3/04

US Classification:

25218233, 423463

Abstract:

The method described herein allows for melt stabilization and vapor-phase synthesis of a cesium germanium halide utilizing germanium dihalides formed in situ. This disclosure allows for the melting of cesium germanium halides without decomposition, which allows for growing crystals of these materials from the melt. This disclosure allows for a direct synthesis of these materials without the use of water or the introduction of other possible contaminants.

US Patent:

52873781, Feb 15, 1994

Filed:

Dec 30, 1992

Appl. No.:

7/998347

Inventors:

Steven R. Bowman - Davidsonville MD
Barry J. Feldman - Arlington VA

Assignee:

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

International Classification:

H01S 314

US Classification:

372 68

Abstract:

The directly pumped holmium (Ho) quasi-two level laser of the invention comprises a directly pumped holmium laser having a host material doped with an amount of holmium ions sufficient to produce an output laser emission at a wavelength of about 2. 1. mu. m when the holmium laser is pumped by a pump beam at a wavelength of about 2. mu. m and a pumping laser for producing the pump beam. In an exemplary embodiment, the pumping laser comprises a Cr,Tm:YAG laser pumped by a flashlamp.

US Patent:

56378831, Jun 10, 1997

Filed:

Feb 27, 1995

Appl. No.:

8/399102

Inventors:

Steven R. Bowman - Davidsonville MD
William S. Rabinovich - Silver Spring MD
Douglas S. Katzer - Alexandria VA
Harry B. Dietrich - Fairfax VA

Assignee:

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

International Classification:

H01L 2906
H01L 310328

US Classification:

257 21

Abstract:

An optically addressed spatial light modulator includes top and bottom conductive layers sandwiching an intrinsic semiconductor multilayer structure. A cladding layer having a high trapping density is sandwiched between at least one of the electrodes and the intrinsic semiconductor layer structure. Typically, one cladding layer will be sandwiched between the top conductive layer and the intrinsic semiconductor multilayer structure and another cladding layer will be sandwiched between the bottom conductive layer and the intrinsic semiconductor structure. The cladding layer or layers laterally confine the photocarriers generated within the intrinsic semiconductor multilayer structure.

US Patent:

57469423, May 5, 1998

Filed:

Jan 31, 1996

Appl. No.:

8/594559

Inventors:

Steven R. Bowman - Davidsonville MD
Barry J. Feldman - Arlington VA
Leslie B. Shaw - Laurel MD

Assignee:

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

International Classification:

H01S 316
H01S 317
H01S 3094
C09K 1177

US Classification:

2523014H

Abstract:

A high-efficiency fluorescent emitter includes an excitation source and a w phonon host doped with erbium. The emitter can be used as a lasing medium or as a phosphor. Typical hosts include RcX. sub. 3 and chalcogenide glasses, wherein Rc is yttrium, gadolinium, lutetium, lanthanum or a mixture thereof, and X is a halogen or a mixture of halogens.