Barry S Feldman

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:

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.

US Patent:

55352324, Jul 9, 1996

Filed:

Jan 31, 1995

Appl. No.:

8/381243

Inventors:

Steven R. Bowman - Davidsonville MD
Joseph Ganem - Reisterstown 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 3091
H01S 3092

US Classification:

372 70

Abstract:

The present invention is a solid state laser, including: (1) a laser cavity defined by a first mirror and an opposing second mirror, where these mirrors are reflective at the output wavelength of the laser; (2) a laser medium disposed in the laser cavity, including a low phonon energy host material, doped with an amount of praseodymium ions sufficient to produce a longitudinal mode laser emission from the transition of the praseodymium ions from the. sup. 3 F. sub. 3 excited state to a lower energy state when the laser medium is pumped by an appropriate pump, where the energy gap between the. sup. 3 F. sub. 3 excited state and the lower energy state corresponds to the output wavelength of the laser; and (3) a pump for the laser medium.