William E Alford

US Patent:

6393038, May 21, 2002

Filed:

Oct 4, 1999

Appl. No.:

09/412044

Inventors:

Thomas D. Raymond - Edgewood NM
William J. Alford - Albuquerque NM
Mary H. Crawford - Albuquerque NM
Andrew A. Allerman - Albuquerque NM

Assignee:

Sandia Corporation - Albuquerque NM

International Classification:

H01S 310

US Classification:

372 22, 372 50, 372 98, 372 75

Abstract:

A frequency-doubled semiconductor vertical-external-cavity surface-emitting laser (VECSEL) is disclosed for generating light at a wavelength in the range of 300-550 nanometers. The VECSEL includes a semiconductor multi-quantum-well active region that is electrically or optically pumped to generate lasing at a fundamental wavelength in the range of 600-1100 nanometers. An intracavity nonlinear frequency-doubling crystal then converts the fundamental lasing into a second-harmonic output beam. With optical pumping with 330 milliWatts from a semiconductor diode pump laser, about 5 milliWatts or more of blue light can be generated at 490 nm. The device has applications for high-density optical data storage and retrieval, laser printing, optical image projection, chemical-sensing, materials processing and optical metrology.

US Patent:

6647033, Nov 11, 2003

Filed:

Apr 30, 2001

Appl. No.:

09/846445

Inventors:

Arlee V. Smith - Albuquerque NM
William J. Alford - Albuquerque NM

Assignee:

Sandia Corporation - Albuquerque NM

International Classification:

H01S 310

US Classification:

372 21, 372 92, 372 97, 372 98, 372100, 372101

Abstract:

An optical parametric oscillator (OPO) having an optical pump, which generates a pump beam at a pump frequency greater than a desired signal frequency, a nonlinear optical medium oriented so that a signal wave at the desired signal frequency and a corresponding idler wave are produced when the pump beam (wave) propagates through the nonlinear optical medium, resulting in beam walk off of the signal and idler waves, and an optical cavity which directs the signal wave to repeatedly pass through the nonlinear optical medium, said optical cavity comprising an equivalently even number of non-planar mirrors that produce image rotation on each pass through the nonlinear optical medium. Utilizing beam walk off where the signal wave and said idler wave have nonparallel Poynting vectors in the nonlinear medium and image rotation, a correlation zone of distance equal to approximately L is created which, through multiple passes through the nonlinear medium, improves the beam quality of the OPO output.

US Patent:

6647034, Nov 11, 2003

Filed:

Apr 30, 2001

Appl. No.:

09/846446

Inventors:

Arlee V. Smith - Albuquerque NM
William J. Alford - Albuquerque NM
Mark S. Bowers - Bothell WA

Assignee:

Sandia Corporation - Albuquerque NM

International Classification:

H01S 310

US Classification:

372 21, 372 22

Abstract:

A method to improving optical parametric oscillator (OPO) beam quality having an optical pump, which generates a pump beam at a pump frequency greater than a desired signal frequency, a nonlinear optical medium oriented so that a signal wave at the desired signal frequency and a corresponding idler wave are produced when the pump beam (wave) propagates through the nonlinear optical medium, resulting in beam walk off of the signal and idler waves, and an optical cavity which directs the signal wave to repeatedly pass through the nonlinear optical medium, said optical cavity comprising an equivalently even number of non-planar mirrors that produce image rotation on each pass through the nonlinear optical medium. Utilizing beam walk off where the signal wave and said idler wave have nonparallel Poynting vectors in the nonlinear medium and image rotation, a correlation zone of distance equal to approximately L is created which, through multiple passes through the nonlinear medium, improves the beam quality of the OPO output.

US Patent:

61477931, Nov 14, 2000

Filed:

Dec 3, 1997

Appl. No.:

8/984654

Inventors:

William J. Alford - Albuquerque NM
Arlee V. Smith - Albuquerque NM

Assignee:

Sandia Corporation - Albuquerque NM

International Classification:

G02F 139

US Classification:

359330

Abstract:

A more efficient class of optical parametric oscillators is made possible by introducing means for reducing signal losses due to backconversion of signal photons in the nonlinear optical medium.

Author:

William P. Alford

ISBN #:

0674014529

Author:

William P. Alford

ISBN #:

0804722706

Author:

William P. Alford

ISBN #:

0804729603