JLA Vol:6 Iss:1 (Measurement of temperature and absorptance for laser processing applications)

Authors:
S. Ramanathan
M. F. Modest
Department of Mechanical Engineering, The Pennsylvania State University, University Park, PA 16802, U.S.A.

The use of CO₂ lasers has been successfully demonstrated for several manufacturing processes such as cutting, drilling, scribing, etc., of a wide range of materials. The absorptance of a material at the laser wavelength and at the material removal temperature substantially affect the efficiency of the laser machining process. Some materials have absorption bands in the mid‐infrared and the absorptance changes drastically with temperature at the CO₂ laser wavelength of 10.6 μm. Additionally, the absor...

JLA Vol:17 Iss:1 (An experimental and numerical study of the influence of diode laser beam shape on thin wall direct metal deposition)

Authors:
Andrew J. Pinkerton
Lin Li
School of Mechanical, Aerospace, and Civil Engineering, The University of Manchester, Sackville Street, Manchester, M60 1QD U.K.

Use of the high powered diode laser (HPDL) for direct metal deposition enables multiple layer cladding to be performed with a nominally rectangular beam, traversed at different angles to the fast axis, or with a fiber-coupled, circular beam. These factors may provide an advantage over the traditional beam profiles of CO₂ and Nd:YAG lasers, so there is a need to examine the effect that they have on the process and final product characteristics. This article reports such an examination. A 1.5 kW ...

JLA Vol:21 Iss:3 (Multibeam fiber laser cutting)

Authors:
Flemming Ove Olsen
Klaus Schuett Hansen
Jakob Skov Nielsen
Department of Mechanical Engineering, Technical University of Denmark, Kongens Lyngby DK-2800, Denmark

The appearance of the high power high brilliance fiber laser has opened for new possibilities in laser materials processing. In laser cutting this laser has demonstrated high cutting performance compared to the dominating cutting laser, the CO₂ laser. However, quality problems in fiber-laser cutting have until now limited its application to metal cutting. In this paper the first results of proof-of-principle studies applying a new approach (patent pending) for laser cutting with h...

JLA Vol:8 Iss:2 (Laser materials processing at Sandia National Laboratories)

Authors:
James L. Jellison
Michael J. Cieslak
Sandia National Laboratories, Albuquerque, NM 87185, U.S.A.

This paper describes the laser materials processing capabilities at Sandia National Laboratories. Some of the advances in the understanding of various aspects of laser materials processing which have been made by the laser materials processing team at Sandia are discussed.

JLA Vol:3 Iss:1 (Nursing Perspective: Clinical Laser Safety Issues Survey)

Authors:
Penny J. Smalley
Laser Resources & Consulting Services, Chicago, Illinois

JLA Vol:25 Iss:4 (Analysis of Yb:YAG thin disk laser resonator considering thermal lens effects: Experimentally and by Laser Cavity Analysis and Design)

JLA Vol:15 Iss:3 (Steady-state laser cutting modeling)

Authors:
Ce´dric Mas
Re´my Fabbro
CLFA, 16 bis Avenue Prieur de la Côte d’Or, 94114 Arcueil Cedex, France

Yannick Goue´dard
OPTIS, ZE la Farlède, BP 275, 83078 Toulon Cedex 9, France

We present a global self-consistent model of the laser cutting process where we have taken into account the main parameters of the process that are the laser beam intensity distribution, the thermal phenomena controlling the melt parameters, the fluid, both cutting gas and melt hydrodynamics, and the local equilibrium of the geometry of the cutting front. This steady state approach provides us with different fluid velocities, surface ...

JLA Vol:19 Iss:3 (Single-Pass and Multi-Pass Laser Cutting of Si–SiC: Assessment of the Cut Quality and Microstructure in the Heat Affected Zone)

Authors:
F. Quintero
J. Pou
F. Lusquin˜os
A. Riveiro
M. Pe´rez-Amor
Departamento Fi´sica Aplicada, E.T.S. Ingenieros Industriales, University de Vigo, 36310 Vigo, Spain

A. J. S. Fernandes
Department of Physics, University of Aveiro, 3810-193 Aveiro, Portugal

Experimental investigations on the laser cutting of thick silicon infiltrated silicon carbide (Si–SiC) elements are presented. Si–SiC is a fully dense ceramic composite with high hardness and chemical and thermal stability, which makes it a valuable material in severe conditions. However, machining is still a challenging task. A...

JLA Vol:24 Iss:3 (2D longitudinal modeling of heat transfer and fluid flow during multilayered direct laser metal deposition process)

Authors:
Simon Morville
Muriel Carin
LIMATB, Universite´ de Bretagne-Sud/UEB, Centre de recherche Ch. Huygens, Rue de Saint Maude´, BP 92116, 56321 Lorient cedex, France

Patrice Peyre
Myriam Gharbi
PIMM, UMR 8006 CNRS-Arts et Me´tiers Paris Tech, 151 Boulevard de l’Hoˆpital, 75013 Paris, France

Denis Carron
Philippe Le Masson
LIMATB, Universite´ de Bretagne-Sud/UEB, Centre de recherche Ch. Huygens, Rue de Saint Maude´, BP 92116, 56321 Lorient cedex, France

Re´my Fabbro
PIMM, UMR 8006 CNRS-Arts et Me´tiers Paris Tech, 151 Boulevard de l’Ho&ci...

JLA Vol:6 Iss:4 (Holographic optical elements (HOEs): A serious application of holography)

Authors:
Gareth T. Williams
Jeff Fredrick
Physics Department, San Jose State University, San Jose, CA, U.S.A.

Without disputing the excitement and sense of accomplishment associated with the production of display holograms, this paper suggests equal rewards from the production of holographic optical elements (HOEs). The elements described here are zone plates, diffraction gratings, interference filters and mirrors, and lenses. Ways of making each of these in an optics teaching laboratory are described, but the main emphasis will be on positive lens HOE.