JLA Vol:24 Iss:3 (Stability limits of laser drilled hole arrays on large areas)

Authors:
Nelli Hambach
Claudia Hartmann
Jens Holtkamp
Arnold Gillner
Fraunhofer Institute for Laser Technology ILT, Steinbachstr. 15, D-52074 Aachen, Germany

Large area microdrilling utilizing short pulsed solid state lasers is a promising manufacturing technique for filtration technology. High degree of perforation and high quality of the drilled hole arrays regarding roundness and diameter variation of holes are the main challenges. The goal is to achieve a high degree of perforation with a high number of round holes on a constant pitch. The resulting variation of hole roundness and mechanical stability limitations of the percussion drilled foi...

JLA Vol:24 Iss:3 (Trepanning drilling of microholes on cemented tungsten carbide using femtosecond laser pulses)

Authors:
Khai Xuan Pham
Rie Tanabe
Yoshiro Ito
Department of Mechanical Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan

Microholes of 100–300 µm diameters were trepanned on cemented tungsten carbide plates of 0.5 and 1 mm thicknesses by means of femtosecond laser pulses using a galvano-scanner with an f-θ lens of 80 mm focal length. It was found that the focus position of the laser beam relative to the sample surface affects the drilled hole shape and drilling speed. Focus on the surface produced a less tapered hole and a higher machining speed than focus 0.5 mm away from the surfa...

JLA Vol:24 Iss:4 (3D-steering and superfocusing of second-harmonic radiation through plasmonic nano antenna arrays)

Authors:
P. Reichenbach
L. M. Eng
U. Georgi
B. Voit
Array

Second-harmonic generation (SHG) of light at nanoparticles provides the possibility to generate light (of a desired frequency) in-situ instead of introducing it by focusing an external light beam. Our theoretical study provides steering SHG light through the superposition of the radiation from a number of nanoparticles which are arranged in a circle. The authors assume cone-shaped or rod-shaped nanoparticles. Their radiation can be modeled as radiating dipoles. The superposition of their fields yields a “hot spot” with a full width at half-maximum of around 100 nm. Eve...

JLA Vol:24 Iss:4 (Cellular reactions toward nanostructured silicon surfaces created by laser ablation)

Authors:
K. Wallat
Institute of Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, Universitaetsstr. 5-7, 45117 Essen, Germany

D. Do¨rr
R. Le Harzic
F. Stracke
D. Sauer
Fraunhofer Institute for Biomedical Engineering (IBMT) and Chair for Molecular and Cellular Biotechnology (University of Saarbruecken), Ensheimer Str. 48, 66386 St. Ingbert, Germany

M. Neumeier
A. Kovtun
Institute of Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, Universitaetsstr. 5-7, 45117 Essen, Germany

H. Zimm...

JLA Vol:24 Iss:4 (Development of functional sub-100 nm structures with 3D two-photon polymerization technique and optical methods for characterization)

Authors:
V. Ferreras Paz
Institut fu¨r Technische Optik, Universita¨t Stuttgart, 70569 Stuttgart, Germany

M. Emons
Institut fu¨r Quantenoptik, Leibniz Universita¨t Hannover, 30167 Hannover, Germany

K. Obata
A. Ovsianikov
S. Peterha¨nsel
K. Frenner
C. Reinhardt
B. Chichkov
U. Morgner
W. Osten
Array

Investigations of two-photon polymerization (TPP) with sub-100 nm in the structuring resolution are presented by using photosensitive sol-gel material. The high photosensitivity of this material allows for TPP using a large variety in lase...

JLA Vol:24 Iss:4 (Direct laser writing-mediated generation of standardized topographies for dental implant surface optimization)

Authors:
Rainer Wittig
Institut fu¨r Lasertechnologien in der Medizin und Messtechnik (ILM) an der Universita¨t Ulm, 89081 Ulm, Germany

Erik Waller
Georg von Freymann
Arbeitsgruppe Optische Technologien und Photonik und Forschungszentrum OPTIMAS, Fachbereich Physik, Technische Universita¨t Kaiserslautern, 67663 Kaiserslautern, Germany

Rudolf Steiner
Institut fu¨r Lasertechnologien in der Medizin und Messtechnik (ILM) an der Universita¨t Ulm, 89081 Ulm, Germany

The functionalization of dental implants, aiming at the improvement of long-term acceptance, is of pivotal interest in dental research. Bone, connectiv...

JLA Vol:24 Iss:4 (EDITORIAL)

Authors:
Andreas Ostendorf

JLA Vol:24 Iss:4 (Experimental and theoretical investigation on fs-laser-induced nanostructure formation on thin gold films)

Authors:
Dirk Wortmann
Lehrstuhl fuer Lasertechnik, RWTH Aachen University, Steinbachstrasse 15, 52074 Aachen, Germany

Ju¨rgen Koch
Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hannover, Germany

Martin Reininghaus
Lehrstuhl fuer Lasertechnik, RWTH Aachen University, Steinbachstrasse 15, 52074 Aachen, Germany

Claudia Unger
Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hannover, Germany

Conny Hulverscheidt
Lehrstuhl fuer Lasertechnik, RWTH Aachen University, Steinbachstrasse 15, 52074 Aachen, Germany

Dmitry Ivanov
Lehr-und Forschungsgebiet Nichtlineare Dynamik, RWTH Aachen Univ...

JLA Vol:24 Iss:4 (Femtosecond laser welded nanostructures and plasmonic devices)

Authors:
A. Hu
P. Peng
H. Alarifi
X. Y. Zhang
J. Y. Guo
Y. Zhou
W. W. Duley
Array

Nanojoining, a burgeoning research area, becomes a key manufacturing of complicated nanodevices with functional prefabricated components. In this work, various nanojoining methods are first reviewed. For nanojoining of Ag/Au nanoparticles, three methods are investigated comparatively. Thermal annealing shows a two-step solid state diffusion mechanism. Laser annealing by millisecond pulses displays the thermal activated solid state diffusion. Meanwhile, two effects have been identified in femtosecond laser irradiation with diffe...

JLA Vol:24 Iss:4 (Femtosecond laser-induced periodic surface structures)

Authors:
J. Bonse
J. Kru¨ger
S. Ho¨hm
A. Rosenfeld
Array

The formation of laser-induced periodic surface structures (LIPSS) in different materials (metals, semiconductors, and dielectrics) upon irradiation with linearly polarized fs-laser pulses (τ ∼ 30–150 fs, λ ∼ 800 nm) in air environment is studied experimentally and theoretically. In metals, predominantly low-spatial-frequency-LIPSS with periods close to the laser wavelength λ are observed perpendicular to the polarization. Under specific irradiation conditions, high-spatial-frequency-LIPSS with sub-100-nm spatial periods (∼λ/10) can be gene...