JLA Vol:24 Iss:4 (Nanogratings in fused silica: Formation, control, and applications)

Authors:
So¨ren Richter
Matthias Heinrich
Sven Do¨ring
Andreas Tu¨nnermann
Stefan Nolte
Ulf Peschel
Array

The authors investigated the formation of periodic subwavelength structures, so-called nanogratings, in the volume of fused silica. These self-organized structures emerge upon irradiation with ultrashort laser pulses, undergoing three distinct stages of growth from randomly distributed nanostructures to extended domains with uniform periodicity. The experiments revealed that the cumulative action of subsequent laser pulses is mediated by dangling-bond type defects. On shorter time scales, transient self t...

JLA Vol:24 Iss:4 (Laser-assisted nanofabrication of carbon nanostructures)

Authors:
Yun Shen Zhou
Wei Xiong
Jongbok Park
Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0511, USA

Min Qian
Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588-0511, USA and Department of Physics, East China Normal University, Shanghai 200062, People’s Republic of China

Masoud Mahjouri-Samani
Yang Gao
Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0511, USA

Lan Jiang
Department of Mechanical and Automation Engineering, Beijing Institute of Technology, Bei...

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...

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 (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:2 (Energetic efficiency of remote cutting in comparison to conventional fusion cutting)

Authors:
M. Lu¨tke
J. Hauptmann
A. Wetzig
Fraunhofer IWS, Winterbergstraße 28, 01277 Dresden, Germany

E. Beyer
Fraunhofer IWS, Winterbergstraße 28, 01277 Dresden, Germany and University of Technology Dresden, 01062 Dresden, Germany

The remote cutting technique provides an enormous potential in terms of cutting speeds when working on thin sheets. Even on contour cutting speeds about 100 m/min are realizable. Working without any cutting gas, the material of the cutting kerf must be vaporized partially. It is evident that the energy input must be higher than for pure melting of the cutting kerf’s material. In order to ...

JLA Vol:24 Iss:2 (Laser induced backside wet and dry etching of solar glass by short pulse ytterbium fiber laser irradiation)

Authors:
He Chao
Liu Furong
Wang Min
Yuan Jianwen
Chen Jimin
Institute of Laser Engineering, Beijing University of Technology, Chaoyang District, Beijing 100124, China

Microstructures fabricated on the surface of solar glass have the potential to improve the performance of solar cells. In this paper, in order to overcome the high transmittance to 1064 nm center wavelength fiber laser irradiation and realize high efficiency process on transparent glass substrates, different absorber materials, including alumina powder, alumina ceramic wafers, and copper sulphate solutions, were applied for dry and wet etching under the irradiation of ...

JLA Vol:24 Iss:2 (Temperature measurement of laser heated metals in highly oxidizing environment using 2D single-band and spectral pyrometry)

Authors:
Maryse Muller
Remy Fabbro
PIMM Laboratory (Arts et Me´tiers ParisTech—CNRS), 151 Bd.de l’Hoˆpital, 75013 Paris, France

Hazem El-Rabii
Institut Prime, CNRS-ENSMA-Universite´ de Poitiers, 1 Ave. Cle´ment Ader, BP 40109, 86961 Futuroscope Chasseneuil Cedex, France

Koji Hirano
Nippon Steel Corporation, Marunouchi Park Building, 2-6-1 Marunouchi, Chiyoda Ward, Tokyo 100-8071, Japan

Calibration and validation of two temperature measurement techniques both using optical pyrometry, usable in the framework of the study of the heated metals in highly oxidizing environments and more generally dur...

JLA Vol:24 Iss:2 (Weld strength of laser-welded hot-press-forming steel)

Authors:
Minjung Kang
Cheolhee Kim
Welding and Joining Research Group, Korea Institute of Industrial Technology, 7–47, Songdo-Dong, Yeonsu-Gu, Incheon 406–840, Republic of Korea

Jongsup Lee
Molding and Forming Technology R&D Group, Korea Institute of Industrial Technology, 7–47, Songdo-Dong, Yeonsu-Gu, Incheon 406–840, Republic of Korea

There is an increasing demand for ultrahigh-strength steel in automotive industries to facilitate the manufacture of lightweight vehicles without compromising their security features. Although transformation-induced plasticity and dual phase steels have strengths of under 1 GPa, boron-alloy...

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...