University of California

Lawrence Livermore National Security, LLC

The United States of America As Represented by the Department of Energy

United States Enrichment Corporation

Onxy Optics, Inc.

Raymond John Beach

Stephen Anthony Payne

Jay Walter Dawson

Eric C Honea

Ralph Henry Page

Michael Joseph Messerly

William F Krupke

Camille Bibeau

William J Benett

Thomas Frederick Soules

Scott Mitchell

Christopher P J Barty

Christopher Allen Ebbers

Barry L Freitas

Steven B Sutton

Scott C Mitchell

Joel Speth

Dennis Maderas

John Lang

Joseph Collin Farmer

Robert J Deri

Alexander M Rubenchik

Michael Dale Perry

Paul H Pax

Bassem S El-Dasher

Richard William Solarz

John Edward Heebner

Helmuth E Meissner

Edward Ira Moses

Dino R Ciarlo

Michael D Feit

Luis E Zapata

Eddy Stappaerts

Ian P Mercer

Kathleen I Schaffers

Howard T Powell

Georg F Albrecht

Isaac Louis Bass

Andy Bayramian

James E Murray

David C Mundinger

Alexander D Drobshoff

Wolfgang Hackenberg

Deanna M Pennington

Sarath K Menon

Terry McNelley

Sheldon Shao Quan Wu

Gary DeBell

Zhi Ming Liao

Domenico Bonaccini Calia

Steven T Mills

Luke Taylor

Eric Honea

Russel B Wilcox

An apparatus for use in a friction stir operation, such as friction stir welding (FSW) or friction stir processing (FSP). The apparatus may have a rotating tool adapted to be plunged into a material, where the material is susceptible to being softened by heating. The rotating tool may further be adapted to be advanced along a surface of the material. An optical energy generating subsystem may be used to heat a portion of the material using optical energy as the tool is advanced along the material.

System and method for light assisted friction stir processing and welding of metallic and non-metallic materials

In one embodiment, a method for forming an alkali resistant coating includes forming a first oxide material above a substrate and forming a second oxide material above the first oxide material to form a multilayer dielectric coating, wherein the second oxide material is on a side of the multilayer dielectric coating for contacting an alkali. In another embodiment, a method for forming an alkali resistant coating includes forming two or more alternating layers of high and low refractive index oxide materials above a substrate, wherein an innermost layer of the two or more alternating layers is on an alkali-contacting side of the alkali resistant coating, and wherein the innermost layer of the two or more alternating layers comprises at least one of: alumina, zirconia, and hafnia.

Alkali resistant optical coatings for alkali lasers and methods of production thereof

In one embodiment, a multilayer dielectric coating for use in an alkali laser includes two or more alternating layers of high and low refractive index materials, wherein an innermost layer includes a thicker, &#x3e;500 nm, and dense, &#x3e;97% of theoretical, layer of at least one of: alumina, zirconia, and hafnia for protecting subsequent layers of the two or more alternating layers of high and low index dielectric materials from alkali attack. In another embodiment, a method for forming an alkali resistant coating includes forming a first oxide material above a substrate and forming a second oxide material above the first oxide material to form a multilayer dielectric coating, wherein the second oxide material is on a side of the multilayer dielectric coating for contacting an alkali.

A deterministic methodology is provided for designing optical fibers that support field-flattened, ring-like higher order modes. The effective and group indices of its modes can be tuned by adjusting the widths of the guide's field-flattened layers or the average index of certain groups of layers. The approach outlined here provides a path to designing fibers that simultaneously have large mode areas and large separations between the propagation constants of its modes.

Optical waveguides having flattened high order modes

Architectures for coherently combining an array of fiber-based lasers are provided. By matching their lengths to within a few integer multiples of a wavelength, the spatial and temporal properties of a single large laser are replicated, while extending the average or peak pulsed power limit.

Phased laser array with tailored spectral and coherence properties

Single, or near single transverse mode waveguide definition is produced using a single homogeneous medium to transport both the pump excitation light and generated laser light. By properly configuring the pump deposition and resulting thermal power generation in the waveguide device, a thermal focusing power is established that supports perturbation-stable guided wave propagation of an appropriately configured single or near single transverse mode laser beam and/or laser pulse.

Hybrid fiber-rod laser

A waveguide includes a cladding region that has a refractive index that is substantially uniform and surrounds a wave-guiding region that has an average index that is close to the index of the cladding. The wave-guiding region also contains a thin ring or series of rings that have an index or indices that differ significantly from the index of the cladding. The ring or rings enable the structure to guide light.

Optical fiber having wave-guiding rings

In one embodiment, a laser oscillator is provided comprising an optical cavity, the optical cavity including a gain medium including an alkali vapor and a buffer gas, the buffer gas includingHe gas, wherein ifHe gas is also present in the buffer gas, the ratio of the concentration of theHe gas to theHe gas is greater than 1.37&#xd7;10. Additionally, an optical excitation source is provided. Furthermore, the laser oscillator is capable of outputting radiation at a first frequency. In another embodiment, an apparatus is provided comprising a gain medium including an alkali vapor and a buffer gas includingHe gas, wherein ifHe gas is also present in the buffer gas, the ratio of the concentration of theHe gas to theHe gas is greater than 1.37&#xd7;10. Other embodiments are also disclosed.

Optically pumped alkali laser and amplifier using helium-3 buffer gas

A system for assisting in observing a celestial object and providing synthetic guide star generation. A lasing system provides radiation at a frequency at or near 938 nm and radiation at a frequency at or near 1583 nm. The lasing system includes a fiber laser operating between 880 nm and 960 nm and a fiber laser operating between 1524 nm and 1650 nm. A frequency-conversion system mixes the radiation and generates light at a frequency at or near 589 nm. A system directs the light at a frequency at or near 589 nm toward the celestial object and provides synthetic guide star generation.

Synthetic guide star generation

A method and apparatus is provided for producing near-diffraction-limited laser light, or amplifying near-diffraction-limited light, in diode pumped alkali vapor photonic-band-gap fiber lasers or amplifiers. Laser light is both substantially generated and propagated in an alkali gas instead of a solid, allowing the nonlinear and damage limitations of conventional solid core fibers to be circumvented. Alkali vapor is introduced into the center hole of a photonic-band-gap fiber, which can then be pumped with light from a pump laser and operated as an oscillator with a seed beam, or can be configured as an amplifier.

Diode pumped alkali vapor fiber laser

An optical fiber amplifier includes a length of silica optical fiber having a core doped with neodymium, a first cladding and a second cladding each with succeeding lower refractive indices, where the first cladding diameter is less than 10 times the diameter of the core. The doping concentration of the neodymium is chosen so that the small signal absorption for 816 nm light traveling within the core is less than 15 dB/m above the other fiber losses. The amplifier is optically pumped with one laser into the fiber core and with another laser into the first cladding.

High power 938 nanometer fiber laser and amplifier

A fast (high numerical aperture) cylindrical microlens, which includes an internally reflective surface, that functions to deviate the direction of the light that enters the lens from its original propagation direction is employed in optically conditioning laser diodes, laser diode arrays and laser diode bars.

Cylindrical microlens with an internally reflecting surface and a method of fabrication

By tapering the diameter of a flanged barrel laser rod over its length, the maximum trapped path length of a barrel mode can be dramatically reduced, thereby reducing the ability of the trapped spontaneous emission to negatively impact laser performance through amplified spontaneous emission (ASE). Laser rods with polished barrels and flanged end caps have found increasing application in diode array end-pumped laser systems. The polished barrel of the rod serves to confine diode array pump light within the rod. In systems utilizing an end-pumping geometry and such polished barrel laser rods, the pump light that is introduced into one or both ends of the laser rod, is ducted down the length of the rod via the total internal reflections (TIRs) that occur when the light strikes the rod's barrel. A disadvantage of using polished barrel laser rods is that such rods are very susceptible to barrel mode paths that can trap spontaneous emission over long path lengths. This trapped spontaneous emission can then be amplified through stimulated emission resulting in a situation where the stored energy available to the desired lasing mode is effectively depleted, which then negatively impacts the laser's performance, a result that is effectively reduced by introducing a taper onto the laser rod.

Tapered laser rods as a means of minimizing the path length of trapped barrel mode rays

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Livermore, CA, United States of America

Raymond John Beach