Proceedings Volume 6161

International Conference on Lasers, Applications, and Technologies 2005: Laser-Assisted Micro- and Nanotechnologies

Vitaly I. Konov, Vladislav Ya. Panchenko, Koji Sugioka, et al.
cover
Proceedings Volume 6161

International Conference on Lasers, Applications, and Technologies 2005: Laser-Assisted Micro- and Nanotechnologies

Vitaly I. Konov, Vladislav Ya. Panchenko, Koji Sugioka, et al.
View the digital version of this volume at SPIE Digital Libarary.

Volume Details

Date Published: 9 February 2006
Contents: 2 Sessions, 23 Papers, 0 Presentations
Conference: International Conference on Lasers, Applications, and Technologies 2005 2005
Volume Number: 6161

Table of Contents

icon_mobile_dropdown

Table of Contents

All links to SPIE Proceedings will open in the SPIE Digital Library. external link icon
View Session icon_mobile_dropdown
  • Laser-assisted Micro- and Nanotechnologies
  • Symposium on Optical Discharge Propagation in Fiber Waveguide
Laser-assisted Micro- and Nanotechnologies
icon_mobile_dropdown
SNOM probes: fabrication and possibilities for imaging, diagnostics and modification of sample surface
V. F. Dryakhlushin, V. P. Veiko
Basic principles of laser assisted and chemical etching processes for scanning near-field optical microscope (SNOM) probes formation and control techniques are presented. The thermal, temporal and chemical regimes are consider in order to provide stable reproducibility and high quality of SNOM probes on the base adiabatically tapered single-mode optical fiber. The advantages of different methods of SNOM fabrication are discussed. Application of scanning near-field microscopy for imaging, spectroscopy, diagnostics and nanolithography with nanometer resolution are observed. The various methods of diagnostics of sample surface and nanometer objects (spectroscopy, near-field photoconductivity, mapping of radiating surfaces and others) are presented. The possibilities of nanometer pattern creation using SNOM for superhigh density data recording and nanoelectronic devices are discussed.
High-precision and high-speed laser microjoining for electronics and microsystems
Arnold Gillner, Alexander Olowinsky, Kilian Klages, et al.
The joining processes in electronic device manufacturing are today still dominated by conventional joining techniques like press fitting, crimping and resistance welding. Laser beam joining techniques have been under intensive investigations and subsequently new processes for mass manufacturing and high accuracy assembling were established. With the newly developed SHADOW(R) welding technology technical aspects such as tensile strength, geometry and precision of the weld could be improved. This technology provides highest flexibility in weld geometry with a minimum welding time as well as new possibilities in using application adapted materials. Different parts and even different metals can be joined by a non-contact process. The application of a relative movement between the laser beam and the part to be joined at feed rates of up to 60 m/min produces weld seams with a length from 0.6 mm to 15.7 mm using a pulsed Nd:YAG laser with a pulse duration of up to 50 ms. Due to the low energy input, typically 1 J to 6 J, a weld width as small as 50 μm and a weld depth as small as 20 pm have been attained. This results in low distortion of the joined watch components. Within this paper this new welding process will be explained and several examples of joined components will be presented with respect to fundamentals and the sustainable implementation of the SHADOW (R) welding technique into watch manufacturing and electronic industry. For microsystem applications the laser joining technology is modified to join even silicon and glass parts without any melting based on the formation of a thermally induced oxygen bond. New fields of applications for joining different materials such as steel to brass or steel to copper for electrical interconnects will be discussed. Here the SHADOW(R) welding technique offers new possibilities for the combination of good electrical properties of copper with high mechanical stiffness of steel. The paper will give a closer look to microjoining applications especially using the SHADOW(R) welding technique. Basics of the process as well as its application on dedicated examples will be shown for small parts such as axis-wheel combinations and electrical connectors.
Femtosecond laser microfabrication of 3D photonic structures
Kock Khuen Seet, Toshiaki Kondo, Vygantas Mizeikis, et al.
The physical principles underlying the three-dimensional (3D) laser microstructuring technique are outlined, its applications for the fabrication of 3D photonic crystals are described. Structures recorded by direct laser writing and holographic recording techniques in SU-8 photoresist are presented along with their structural and optical characterization.
Photoacoustic and vaporization pressure behavior in absorbing liquids heated by infrared laser pulses
S. N. Andreev, K. N. Firsov, I. G. Kononov, et al.
Results of pressure measurements in absorbing liquid (water) heated by CO2 and HF laser pulses are presented. Photoacoustic and vaporization pressure behavior in the case of bulk heating has been investigated and theoretically analyzed.
Plasma channel formation and micromodification of KDP crystal by tightly focused Cr:forsterite femtosecond laser radiation
Experiments on single pulse plasma channel formation in non-linear KDP crystal by tightly focused (NA = 0.47) fundamental and doubled Cr:forsterite laser radiation with energy of 0.1 ÷ 10 μJ and 100 fs pulse duration were carried out. We propose the simple model of non-linear absorption of femtosecond laser radiation in plasma channel. This model allows estimate laser intensity in the channel and plasma parameters.
Effect of air breakdown on short-pulsed laser drilling
T. V. Kononenko, S. M. Klimentov, V. I. Konov, et al.
Laser-induced air breakdown near a steel target surface ablated by short (300 ps and 10 ns) laser pulses was studied with optical emission spectroscopy to determine conditions of the breakdown ignition and time-integrated spatial localization of the laser plasma. The air breakdown was found to occur in a wide range (5-1000 mbar) of ambient air pressures, if the energy density exceeds ~10 J/cm2 for the IR radiation (λ=1078 nm) and ~40 J/cm2 for the visible light (λ=539 nm). Both the crater bottom ablation and evaporation of residual metal droplets suspended in air can ignite the low-threshold air breakdown. The experiments on deep laser drilling of steel demonstrate a sharp decrease of the drilling rate and simultaneous increase of the crater entrance diameter after the crater depth reaches a critical value. The critical crater depth increases with the applied energy density, under decrease of the ambient air pressure and under shortening of the laser pulses. The critical depth correlates with longitudinal shift of the time-integrated maximum plasma emission away from the ablated surface. Noticeable etching of the crater walls by the laser-induced plasma is observed, if movement of the plasma plume away from the ablated surface is stopped by the ambient air before the plasma leaves the crater. Interaction of the plasma with the crater walls should block ejection of the melt phase which is proposed as a reason for the observed sharp decrease of the drilling rate in a deep crater.
Laser chemical vapor deposition of nanometric structures and their electrical and optical properties
S. A. Mulenko, M. S. Brodyn, V. Ya. Gayvoronsky
Laser chemical vapor deposition (LCVD) method based on Ar+ laser radiation was applied for the synthesis of nanometric structures based on iron oxides Fe2O3-x (0 < or = x < or = 1) in the form of thin films. These structures were formed while deposition of elements from iron carbonyl vapors (Fe(CO)5). The thickness of deposited films was no more than 30 nm while deposition on the Si substrate surface and on the SiO2 substrate surface. Deposited thin films demonstrated typical semiconductor trends of specific conductivity in the range (340-170)K. Obtained semiconductor thin films based on iron oxides had the band gap for intrinsic conductivity (Eg) less than 1.0 eV. It was found out that electrical properties of these films were determined by the surface morphology of them and their content of iron oxides. Deposited films demonstrated a large third-order nonlinear optical (NLO) susceptibility (x(3)). While pumping of narrow band gap semiconductor thin film with a frequency-doubled mode-locked Nd:YAG laser (λL=532 nm) and pulse duration of 30 ps (FWHM) at power density less than 100 MW/cm2, the meaning of x(3) was about 5×10-6 e.s.u.
Investigation of parameters of nanostructures, formed by intracavity processing of solid surfaces
Vladimir P. Osipov, Vladimir S. Starovoitov
There are shown the results of experimental investigation of parameters of laser-formed periodic nanostructuring of metal film by means of intracavity processing in the resonator of ruby laser with laser radiation wavelength 0.69 micrometers. AFM-treatment of formed nanostructures profiles has shown the possibility to form multiple periodic structures with characteristic sizes less 200 nanometers during one laser pulse.
Effect of high repetition rate on pulsed laser ablation in gas environment
P. A. Pivovarov, S. M. Klimentov, V. I. Konov, et al.
Pulsed laser drilling in steel was explored in a wide range of repetition rates (up to 200 kHz) at variable pressure of the ambient air. A critical repetition rate was established, exceeding of which drastically increased productivity of ablative drilling. The phenomenon was attributed to formation of a long-living domain (> 100 μs) with hot rarefied atmosphere in the vicinity of the ablated spot or inside the drilled channel. This rarefication was shown to reduce the plasma screening effect, which allows creation of quasi-vacuum conditions for laser ablative technology avoiding vacuum-pumped facilities.
Pulsed laser deposition of europium borate glass films and their optical and magneto-optical properties
A. S. Aleksandrovsky, A. S. Krylov, A. M. Potseluyko, et al.
The ablation with XeCl laser is used for the deposition of europium borate glass thin films. Optical spectra of these films show no indications of the presence of trivalent europium, contrary to the material of the target. UV absorption spectra of the films Magneto-optical activity of the deposited films is demonstrated with the help of magnetic circular dichroism spectra in the spectral range 320 - 450 nm.
Phase transformations in CdZnTe crystals induced by nanosecond laser irradiation
O. Cibulka, V. Cháb
Dynamics of phase transitions induced by nanosecond laser pulses in cadmium zinc telluride wafers were studied with the time-resolved reflectivity method to determine basic thermodynamic parameters and chemical changes as a function of applied pulses and their energy density. The reflectivity spectra were recorded for the energy density range 140 - 3400mJ.cm-2. Chemical decomposition of the CdZnTe alloy appears at the threshold energy density about 300 mJ.cm-2 and this decomposition shifts transparency of the CdZnTe to the visible light.
Application of near-infrared pyrometry for monitoring of temperature evolution at contact surface of circuit breaker
M. Doubenskaia, Ph. Bertrand, Ch. Arnoux, et al.
Advanced pyrometers were applied for surface temperature monitoring during Nd:YAG laser pulsed and pulsed-periodic action on circuit breaker contacts (Ag based composite material with graphite inclusions). Temperature evolution, heating and cooling rates, melting threshold are measured and discussed.
Numerical simulation of dynamics of phase transitions induced in CdTe by nanosecond laser irradiation
A. A. Kovalev, S. P. Zhvavyi, G. L. Zykov
The results of numerical simulation of nanosecond radiation ruby laser influence on cadmium telluride have shown that evaporation process essentially affects the dynamics of phase transitions in the near-surface region of cadmium telluride. Intensive evaporation results in the material surface cooling forming a nonmonotone temperature profile with maximum temperature in semiconductor volume at the distance of ~ 20 nm from the surface. The melt formed under the surface at energy radiation density exceeding the threshold value extends to the surface and to the volume of semiconductor as well. As a result of evaporation and diffusion of cadmium telluride components in the melt the near-surface region is enriched with tellurium. While modeling, the dependence of crystallization temperature and phase transition latent heat upon the components concentration in the melt was used, which allowed us to receive a satisfactory agreement with the experimental data concerning melt duration dependence upon energy density.
Layer-by-layer laser spectral microanalysis of art painting
N. M. Kozhukh, E. V. Klyachkovskaya, V. A. Rozantsev, et al.
A technique is proposed of layer-by-layer laser spectral microanalysis of art pigments, using two-pulse sample atomization with one-shot spectrum registration. The analysis includes on-surface and in-depth profiling of the layer composition. The technique allows to determine distributions of chosen elements along specimen surface. The laser parameters were chosen to obtain regular laser craters of known depth and diameters. The technique has been tested and optimized at the analysis of model samples with known compositions. The proposed method was used for investigation and ascription two painting from Nesvizh Portrait Gallery (Belarus). The results show good prospects of the LIBS as applied to paintings authentication.
Numerical modeling of laser annealing of thin electroceramic materials
The physical-mathematical model and 2D code "TEPOL" are developed to simulate the laser annealing of thin electroceramic samples. The results of test problem calculations have been presented in this paper. We have discussed the opportunity to improve the homogeneously of sample heating by using the transparent cover for ferroelectric heterostructures.
Laser swelling of polymer-like materials by nanosecond pulses: modeling
A. Yu. Malyshev, N. M. Bityurin
Mechanisms of laser swelling of polymers are considered. A theoretical model for one of the mechanisms is studied in detail. According to this model, swelling is provided by a thermo-elastic wave generated in the material by the laser pulse. The tensile stresses in this wave result in elastic and plastic deformation of polymer in the heated region and formation of a hump structure. The value of the threshold laser pulse fluence for the permanent hump formation and an expression for the permanent hump height are obtained analytically. The model allows us to explain earlier experimental data on laser swelling of PMMA film by UV laser pulses.
Optical and structural characteristics of ZnO films doped with gallium
O. A. Novodvorsky, V. Ya. Panchenko, O. D. Khramova, et al.
The ZnO films have been produced on the monocrystalline sapphite substrates (0001) by the pulsed laser deposition method. The photoluminescence spectra of these films have been obtained. The dependence of ZnO films transmission on the gallium admixture concentration has been determined for the spectral region of 200 to 3200 nm. it has been ascertained that the increase in gallium admixture is responsible for the shift of fundamental absorption band edge to the blue, and for the reduction in ZnO films transparency in the IR region. The dependence of the crystallographic parameters (lattice constant C) on the gallium admixture concentration and on the deposition parameters has been found.
Phase-structure transitions of glass-ceramics under IR-laser action: main peculiarities
V. P. Veiko, B. Yu. Novikov, P. A. Skiba, et al.
The main peculiarities of laser-induced structure modification in TiO2-SiO2 based glass-ceramics are experimentally investigated and discussed. The rates of such phase-structure transitions under laser heating are about 102-103 times higher than under conventional heating in a furnace. The laser technology of structural modification in glass-ceramics is very attractive for development and fabrication of new microcomponents and devices.
Third optical harmonic generation at silicon surfaces structured by femtosecond laser pulses
S. V. Zabotnov, I. A. Ostapenko, L. A. Golovan, et al.
Silicon based microstructures with the polarization-dependent ripples were formed under femtosecond laser irradiation of (100) Si surfaces. The structures exhibit a total modification of the orientation dependence of the third optical harmonic in comparison with crystalline silicon.
Nanoconstructions based on double-stranded DNA molecules and their applications as optical biosensing units
M. A. Zakharov, G. M. Kazankov, V. S. Sergeeva, et al.
We describe the formation and the properties of biosensing units based on the cholesteric liquid-crystalline dispersions of the double-stranded nucleic acid molecules. The resulting biosensing units are proved to be sensitive to the presence of some relevant chemical or biological compounds in a liquid to be analyzed.
Symposium on Optical Discharge Propagation in Fiber Waveguide
icon_mobile_dropdown
Ultrahigh-speed videography of fiber fuse propogation: a tool for studying void formation
Shin-ichi Todoroki
Ultrahigh-speed videography of fiber fuse propogation through single mode silica fiber revealed that asymmetric, or tailed, optical discharge pumped by more than 2.0 W of CW 1480nm light generates periodic voids, whereas symmetric one gives a thin continuous void. A number of optical micrographs showing front part of fiber fuse damage pumped by same energy were collected and sorted in the order of increasing disrance between the top of the first big void and the top of the first regular void, The sorted sequence suggests the periodic void formation by the optical discharge; the discharge forms an asymmetric void and casts off its tail which shrinks to be one of regular voids. This process helps us to understand why the regular void looks like a bullet considering the internal pressure of the optical discharge and the temperature gradient along the fiber.
Plasma in bright spot and nature of void chain in fiber fuse track
S. I. Yakovlenko
A qualitative explanation of effect of formation of a chain of equidistant cavities at laser destruction of a fiber core is proposed. It is shown that periodicity of cavities can be caused by instability of new type. On border of plasma and a liquid there is a double layer of charges of high density. In view of repulsion between of the same charges the surface aspires to increase. That provides development of the instability resulting in formation of a chain of cavities. The simple mechanism of instability is proposed. The pressure caused by repulsion of charges on border plasma-liquid leads to formation of a stream between the isotherms corresponding to plasma-liquid border and the liquid-solid substance border. Essential development of instability takes place, when speed of a squeezed out liquid is compared to speed of a bright spot movement. The squeezed out liquid forms the "bridge". The form of a cavity as a bullet flying on laser radiation is caused by pointedness of the isotherms.
In-situ observation of fiber-fuse ignition
Shin-ichi Todoroki
Ultrahigh-speed video recording of fiber-fuse ignition was reported for the first time. Fiber fuse was initiated in a glass ferrule in which the fiber end was in contact with cobalt oxide powder. Optical discharge emerged from a slowly moving darker radiant at about 300μm distance from the fiber end. Absence of void in the trajectory of the dark radiant implies that there is no glass-plasma interface at the radiant. Two other types of fused damage on ignition were also reported.