共查询到10条相似文献,搜索用时 125 毫秒
1.
A. Marcinkevičius V. Mizeikis S. Juodkazis S. Matsuo H. Misawa 《Applied Physics A: Materials Science & Processing》2003,76(2):257-260
We studied the peculiarities of femtosecond laser microfabrication in silica glass with a refractive index that did not exactly
match the value for which the focusing optics is designed. Spherical aberrations resulting from a small refractive index mismatch
were found to increase the size and distort the shape of photodamaged regions, thus reducing the spatial resolution of the
microfabrication. However, these undesirable effects can be minimized, providing that the focusing depth inside the glass
is not too large, and the laser intensity is kept close to the light-induced damage threshold.
Received: 3 December 2001 / Accepted: 11 April 2002 / Published online: 10 September 2002
RID="*"
ID="*"Corresponding author. Fax: +81-88/656-7598, E-mail: misawa@eco.tokushima-u.ac.jp 相似文献
2.
E. Majkova S. Luby R. Senderak Y. Chushkin M. Jergel I. Zergioti D. Papazoglou A. Manousaki C. Fotakis 《Applied Physics A: Materials Science & Processing》2003,76(5):763-766
The sub-picosecond laser microstructuring of multilayer gratings is presented in this paper. A micromachining system operating
with a 0.5 ps KrF laser at 248 nm was used to etch grating structures with a groove width of 1–2 μm in Mo/Si and Si/Mo multilayers.
Atomic force microscopy, scanning electron microscopy and X-ray reflectivity were used to characterize the microetched patterns.
The ω-scans around the 1st Bragg maximum show symmetric satellites up to 3rd order, with positions corresponding to the grating
period. The use of sub-picosecond laser pulses minimizes the thermally affected zone and enhances the quality of the etched
features. Short pulse laser processing is advantageous for the fabrication of high spatial resolution microstructures required
in X-ray optics.
Received: 21 May 2002 / Accepted: 19 August 2002 / Published online: 15 January 2003
RID="*"
ID="*"Corresponding author. Email: dpapa@iesl.forth.gr 相似文献
3.
We report the observation of light filaments produced by a picosecond laser pulse in the visible. The pulse trapped in the
filamentary mode experiences large-scale self-phase modulation, with almost 100-fold spectral broadening along with apparent
shortening of the leading edge. Spatial-temporal properties of the light filament reveal rather complex propagation dynamics.
Received: 7 August 2002 / Revised version: 12 September 2002 / Published online: 11 December 2002
RID="*"
ID="*"Corresponding author. Fax: +370-2/3660-06, E-mail: audrius.dubietis@ff.vu.lt 相似文献
4.
Modification of the fused silica glass network associated with waveguide fabrication using femtosecond laser pulses 总被引:1,自引:0,他引:1
J.W. Chan T.R. Huser S.H. Risbud D.M. Krol 《Applied Physics A: Materials Science & Processing》2003,76(3):367-372
Atomic-scale structural changes have been observed in the glass network of fused silica after modification by tightly focused
800-nm, 130-fs laser pulses at fluences between 5 and 200 J cm-2. Raman spectroscopy of the modified glass shows an increase in the 490 and 605-cm-1 peaks, indicating an increase in the number of 4- and 3-membered ring structures in the silica network. These results provide
evidence that densification of the glass occurs after exposure to fs pulses. Fluorescence spectroscopy of the modified glass
shows a broad fluorescence band at 630 nm, indicating the formation of non-bridging oxygen hole centers (NBOHC) by fs pulses.
Waveguides that support the fundamental mode at 633 nm have been fabricated inside fused silica by scanning the glass along
the fs laser beam axis. The index changes are estimated to be approximately 0.07×10-3.
Received: 17 December 2001 / Accepted: 9 July 2002 / Published online: 25 October 2002
RID="*"
ID="*"Corresponding author. Fax: +1-925/423-2463, E-mail: dmkrol@ucdavis.edu 相似文献
5.
Photofabrication of periodic microstructures in azodye-doped polymers by interference of laser beams 总被引:4,自引:0,他引:4
Volume holographic gratings and two-dimensional periodic microstructures in azodye-doped polymethylmethacrylate were fabricated,
respectively, by interference of two coherent beams of a femtosecond laser and by interference of three coherent beams of
a nanosecond laser. The dependence of the first-order Bragg diffraction efficiency and the photoinduced refractive-index modulation
of the gratings on the intensity of the writing light was investigated. The measurements of the absorption spectra before
and after irradiation with the writing light suggest that the photoinduced gratings were refractive-index-modulated gratings,
which arose from a photoinduced decomposition reaction of the azodye molecules through multiphoton absorption. In the experiments
involving the interference of three beams, the period of the two-dimensional periodic microstructures was changed by adjusting
the angle between the three writing beams.
Received: 10 July 2002 / Revised version: 5 September 2002 / Published online: 20 December 2002
RID="*"
ID="*"Corresponding author. Fax: +81-774/955206, E-mail: jhsi@photon.jst.go.jp 相似文献
6.
V.G. Savitski A.M. Malyarevich K.V. Yumashev B.D. Sinclair A.A. Lipovskii 《Applied physics. B, Lasers and optics》2003,76(3):253-256
Diode-pumped Nd:YVO4 and Nd:KGW lasers passively Q-switched with PbS-quantum dot-doped phosphate glass were demonstrated. For the Nd:YVO4 laser, pulses 110 ns in duration with a 13% Q-switching efficiency were obtained. The absorption recovery time of the PbS-doped
glass was measured to be 27±4 ps. Some recommendations for more efficient use of PbS-doped glasses for Q-switching of diode-pumped
lasers are suggested on the basis of our analysis.
Received: 29 July 2002 / Revised version: 18 September 2002 / Published online: 12 February 2003
RID="*"
ID="*"Corresponding author. Fax: +375-17/232-6286, E-mail: savitski@eudoramail.com 相似文献
7.
Random deflection of the white light beam during self-focusing and filamentation of a femtosecond laser pulse in water 总被引:1,自引:0,他引:1
W. Liu O. Kosareva I.S. Golubtsov A. Iwasaki A. Becker V.P. Kandidov S.L. Chin 《Applied physics. B, Lasers and optics》2002,75(4-5):595-599
Ti:sapphire femtosecond laser pulse filamentation in competition with optical breakdown in condensed matter is studied both
experimentally and numerically using water as an example. Strong random deflection and modulation of the supercontinuum under
tight focusing conditions were observed. They manifest the beginning of the filamentation process near the highly disordered
plasma created by optical breakdown at the geometrical focus.
Received: 13 June 2002 / Revised version: 16 August 2002 / Published online: 25 October 2002
RID="*"
ID="*"Corresponding author. Fax: +1-418/656-2623, E-mail: wliu@phy.ulaval.ca 相似文献
8.
Rapid formaldehyde monitoring in ambient air by means of mid-infrared cavity leak-out spectroscopy 总被引:1,自引:0,他引:1
H. Dahnke G. von Basum K. Kleinermanns P. Hering M. Mürtz 《Applied physics. B, Lasers and optics》2002,75(2-3):311-316
We report the spectroscopic detection of formaldehyde in ambient air using cavity leak-out spectroscopy, a cw variant of cavity
ring-down spectroscopy. This technique proved to be suitable for a real-time quantitative analysis of polluted air without
any preprocessing of the air sample. Using a tunable CO-overtone sideband laser for the λ=3 μm spectral region and a ring-down
cell with R=99.95% mirrors, we achieved a detection limit of 2 parts per billion formaldehyde in ambient air, corresponding
to a minimum detectable absorption coefficient of 7×10-9/cm (sampling time: 2 s). Calibration problems arising from the polarity of the molecule and due to HITRAN database uncertainties
are discussed.
Received: 28 March 2002 / Revised version: 7 June 2002 / Published online: 21 August 2002
RID="*"
ID="*"Corresponding author. Fax: +49-211/811-3121, E-mail: muertz@uni-duesseldorf.de 相似文献
9.
100-W average-power, high-energy nanosecond fiber amplifier 总被引:5,自引:0,他引:5
J. Limpert S. Höfer A. Liem H. Zellmer A. Tünnermann S. Knoke H. Voelckel 《Applied physics. B, Lasers and optics》2002,75(4-5):477-479
We report on the fiber-based amplification of a Q-switched Nd:YAG thin-disk laser. At repetition rates between 3 and 50 kHz
output powers up to 100 W are generated. Pulse energies up to 4 mJ, with diffraction-limited beam quality, are generated in
a 30-μm Yb-doped large-mode-area fiber, furthermore pulse energies up to 8 mJ are achieved from a multimode fiber amplifier.
Received: 8 May 2002 / Revised version: 10 July 2002 / Published online: 25 October 2002
RID="*"
ID="*"Corresponding author. Fax: +49-3641/65-7680, E-mail: Jens.Limpert@uni-jena.de 相似文献
10.
N. Yasumaru K. Miyazaki J. Kiuchi 《Applied Physics A: Materials Science & Processing》2003,76(6):983-985
We report observation of nanostructures formed on thin TiN and DLC films that were irradiated by 800- and 267-nm, femtosecond
(fs) Ti:sapphire laser pulses at an energy fluence slightly above the ablation threshold. On the ablated thin-film surfaces,
the linearly polarized fs pulses produce arrays of fine periodic structures that are almost oriented to the direction perpendicular
to the laser polarization, while the circularly polarized light forms fine-dot structures. The size of these surface structures
is 1/10–1/5 of the laser wavelength and decreases with a decrease in the laser wavelength.
Received: 3 September 2002 / Accepted: 4 September 2002 / Published online: 17 December 2002
RID="*"
ID="*"Corresponding author. Fax: +81-778/62-3306, E-mail: yasuma@fukui-nct.ac.jp 相似文献