JLA Vol:20 Iss:1 (Laser doping of chromium in 6H-SiC for white light emitting diodes)

Authors:
Sachin Bet
Laser-Aided Manufacturing, Materials, and Microprocessing Laboratory (LAMMMP), College of Optics and Photonics, Center for Research and Education in Optics and Lasers (CREOL), MMAE, University of Central Florida, Orlando, Florida 32816-2700

Nathaniel Quick
Applicote Associates, LLC, 1445 Dogner Pl., Ste. 23, Sanford, Florida 32771

Aravinda Kar
Laser-Aided Manufacturing, Materials, and Microprocessing Laboratory (LAMMMP), College of Optics and Photonics, Center for Research and Education in Optics and Lasers (CREOL), MMAE, University of Central Florida, Orlando, Florida 32816-2700

Laser doping has been utilized for fabrica...

JLA Vol:20 Iss:1 (Nanostructure and sp¹/sp² clustering in tetrahedral amorphous carbon thin films grown by femtosecond laser deposition)

Authors:
A. Hu
Department of Physics, University of Waterloo, 200 University Ave. West, Waterloo, ON, N2L 3G1, Canada

M. Rybachuk
Faculty of Built Environment and Engineering, Queensland University of Technology, Gardens Point O 401, GPO Box 2434 Brisbane Qld 4001 Australia

I. Alkhesho
Q.-B. Lu
W. Duley
Department of Physics, University of Waterloo, 200 University Ave. West, Waterloo, ON, N2L 3G1, Canada

Diamondlike amorphous carbon films have been deposited on silicon and quartz substrates by laser ablation of graphite using 120 fs pulses from an amplified Ti:sapphire laser operating at 800 nm. Ultraviole...

JLA Vol:20 Iss:1 (Optimization of production rate in diode laser hardening)

Authors:
Edoardo Capello
Barbara Previtali
Dipartimento di Meccanica, Politecnico di Milano, Via Bonardi 9, 20133 Milano, Italy

The present paper is a contribution to the definition of optimal laser hardening conditions with production rate as the main goal. When the part to be treated is given, the optimization problem can be expressed in terms of minimal execution time subjected to two constraints: the depth of treatment and hardness of transformed layer. When the analytical expression of the objective function and the constraints was determined, the feasibility area was described and analyzed. Finally, an optimization algorithm was applied to identify the optimal solut...

JLA Vol:20 Iss:1 (Practical and theoretical investigations into inert gas cutting of 304 stainless steel using a high brightness fiber laser)

Authors:
Martin Sparkes
Markus Gross
Steven Celotto
Tao Zhang
William O’Neill
Centre for Industrial Photonics, Institute for Manufacturing, Department of Engineering, University of Cambridge, Cambridge, CB2 1RX, United Kingdom

A 2.2 kW fiber laser was used in a series of inert cutting trials on stainless steels of section thicknesses in the range of 6–10 mm. Variations in the cutting performance with changing gas pressure, focal position, and nozzle diameter were investigated. Results showed the difficulties associated in cutting with high brightness lasers, specifically in obtaining full melt eject through narr...

JLA Vol:20 Iss:1 (Surface preparation by using laser cleaning in thermal spray)

Authors:
H. Li
S. Costil
H-L. Liao
C. Coddet
LERMPS, Universite´ de Technologie de Belfort-Montbe´liard, 90010 Belfort Cedex, France

V. Barnier
R. Oltra
LRRS, Universite´ de Bourgogne, 21078 Dijon, France

Pulsed laser cleaning has emerged as a promising technology to challenge traditional surface preparation methods. This paper introduces the PROTAL® process, which combines an in situ pulsed laser cleaning with thermal spraying techniques. This laser surface preparation avoids some drawbacks of the traditional degreasing and sand-blasting stages prior to thermal spraying, which is ...

JLA Vol:20 Iss:2 (<em>In vivo</em> and <em>in vitro</em> evaluation of the corneal damage induced by 1573&ensp;nm laser radiation)

Authors:
Daniel Courant
Catherine Chapel
Ce´line Billy
Service de Radiobiologie et d’Oncologie, IRCM-DSV, Commissariat à l’Energie Atomique, BP 6, Fontenay aux roses, 92265, France

Nicole Salès
Service d’Immuno-Virologie, IMETI-DSV, Commissariat à l’Energie Atomique, BP 6, Fontenay aux roses, 92265, France

Jean-Claude Pe´rot
Christophe Pothier
Lasers Optique et Thermique, CEP, Direction des Centres d’Essai et d’Expertise, 16bis avenue Prieur de la Cŏte d’Or, 94114, Arcueil, France

This study involved the corneal effects of t...

JLA Vol:20 Iss:2 (Connection of macro-sized double-walled carbon nanotube strands by current-assisted laser irradiation)

Authors:
Tao Gong
Yong Zhang
Wenjin Liu
Jinquan Wei
Kunlin Wang
Dehai Wu
Minlin Zhong
Key Laboratory for Advanced Materials Processing Ministry of Education, Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China

Macro-sized (centimeters long) double-walled carbon nanotube (DWNT) strands were connected by current-assisted laser irradiation after bandaging their overlapped ends with DWNT films. During the laser processing, structural transformation of DWNT bundles happened at the joints, which provided molecular bonding between the strands. Tensile tests indicate that the joints mad...

JLA Vol:20 Iss:2 (Design and validation of a hybrid laser/water-jet machining system for brittle materials)

Authors:
Dinesh Kalyanasundaram
Gamal Shehata
Clayton Neumann
Pranav Shrotriya
Pal Molian
Department of Mechanical Engineering, Laboratory for Lasers, MEMS and Nanotechnology, Iowa State University, Ames, Iowa 50011-2161

A unique laser/water-jet (LWJ) cutting head has been designed, built, and interfaced with a CO₂ laser for cutting and scribing of hard and brittle ceramic materials. Alumina samples were used to validate the effectiveness of the LWJ cutting head in thermal fracture mode. The results were compared with vaporization mode (focused beam) as well as thermal fracture mode (defocused beam) of air-assisted laser c...

JLA Vol:20 Iss:2 (Laser bioeffects associated with ultrafast lasers: Role of multiphoton absorption)

Authors:
Randolph D. Glickman
Department of Ophthalmology, University of Texas Health Science Center, San Antonio, Texas 78229-3900

Thomas E. Johnson
Department of Environmental and Radiological Health Sciences, Colorado State University, Ft. Collins, Colorado 80523

Gary D. Noojin
David J. Stolarski
Michael L. Denton
Northrup Grumman Warfighter and Applications Department, San Antonio, Texas 78228-1330

Neeru Kumar
Department of Ophthalmology, University of Texas Health Science Center, San Antonio, Texas 78229-3900

Benjamin A. Rockwell
US Air Force Research Laboratory, AFRL/HEDO, Brooks City...

JLA Vol:20 Iss:2 (Laser endotaxy in silicon carbide and PIN diode fabrication)

Authors:
Z. Tian
Laser-Aided Manufacturing, Materials, and Microprocessing Laboratory, College of Optics and Photonics/CREOL, University of Central Florida, Orlando, Florida 32816-2700

N. R. Quick
AppliCote Associates, LLC, 1445 Dolgner Pl., Sanford, Florida 32771

A. Kar
Laser-Aided Manufacturing, Materials, and Microprocessing Laboratory, College of Optics and Photonics/CREOL, University of Central Florida, Orlando, Florida 32816-2700

A laser solid phase diffusion technique has been utilized to fabricate endolayers in n-type 6H-SiC substrates by carbon incorporation. X-ray energy dispersive spectroscopic analysis shows that the thickness of...