共查询到20条相似文献,搜索用时 203 毫秒
1.
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
2.
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
3.
We demonstrate, for the first time to our knowledge, operation of a self-adaptive holographic laser with wavelength selection,
which uses Nd:YLF as the gain medium. The holographic laser was self-starting and, by virtue of the temporal dynamics in writing
the gain grating, passively Q-switched the cavity to produce pulses with 20–50 ns duration. A pulse energy of 184 mJ was obtained
from the system with beams having a TEM00 spatial profile. Single-longitudinal-mode operation was observed with near-transform-limited bandwidth.
Received: 30 July 2002 / Revised version: 1 October 2002 / Published online: 26 February 2003
RID="*"
ID="*"Corresponding author. Fax: +44-20/7594-7744, E-mail: s.y.lam@ic.ac.uk 相似文献
4.
5.
Fabrication of planar gratings by direct ablation using an ultrashort pulse laser in a common optical path configuration 总被引:4,自引:0,他引:4
K. Venkatakrishnan N.R. Sivakumar B. Tan 《Applied Physics A: Materials Science & Processing》2003,76(2):143-146
Planar gratings have wide applications and to date, many methods for the fabrication of gratings have been reported. Ultrashort
pulse lasers have been used for the machining of gratings primarily because they allow direct ablation and the manufacturing
of sub-wavelength structures. In this paper, we present a novel direct ablation technique for the fabrication of planar gratings
which makes use of the interference of ultrashort pulses in a common optical path configuration. This technique of grating
fabrication not only simplifies the optical setup, but also immunizes the system to extraneous and inherent vibrations, thus
enabling the manufacturing of planar gratings of good edge acuity. We have successfully fabricated planar gratings on a copper
substrate.
Received: 6 November 2001 / Accepted: 4 March 2002 / Published online: 10 September 2002
RID="*"
ID="*"Corresponding author. Fax: +65/77-904-674, E-mail: mvenkata@ntu.edu.sg 相似文献
6.
L. Nedelchev L. Nikolova A. Matharu P.S. Ramanujam 《Applied physics. B, Lasers and optics》2002,75(6-7):671-676
A study of the propagation of elliptically polarized light and the resulting formation of macroscopic chiral structures in
a series of azobenzene side-chain copolyesters, in which the morphology is varied from liquid crystalline to amorphous, is
reported. Real-time measurements are presented, showing the dynamic behavior of the photoinduced rotation of the polarization
ellipse in the different samples. The relationship between the ellipticity of the recording light and the linear birefringence
induced is studied. A numerical solution that takes into account the influence of the photoinduced linear dichroism on the
light propagation through the samples is presented.
Received: 10 June 2002 / Revised version: 26 July 2002 / Published online: 15 November 2002
RID="*"
ID="*"Corresponding author. Fax: +45-4677/4588, E-mail: lian.nedelchev@risoe.dk
RID="**"
ID="**"Permanent address: Department of Chemistry and Physics, The Nottingham Trent Unversity, Clifton Lane, Nottingham NG11 8NS,
England 相似文献
7.
S. Knappe M. Stähler C. Affolderbach A.V. Taichenachev V.I. Yudin R. Wynands 《Applied physics. B, Lasers and optics》2003,76(1):57-63
We have studied the dispersion and absorption line shapes of coherent population trapping resonances (dark resonances) in
thermal cesium vapor. Outside the time-of-flight regime the line shapes can be described by a simple phenomenological model:
a sum of a dispersive and an absorptive Lorentzian of identical width and position, whose relative weights depend on the detuning
of the laser frequencies from the optical resonance. This functional form can be derived from a theoretical model for the
full multilevel structure of an alkali atom. The analytical expressions for the parameters of the line shape model show the
same behavior as the experimental data.
Received: 4 October 2002 / Revised version: 30 October 2002 / Published online: 8 January 2003
RID="*"
ID="*"Corresponding author. Fax: +41-26/300-9631, E-mail: robert.wynands@unifr.ch 相似文献
8.
Surface nanostructuring of silicon 总被引:1,自引:0,他引:1
A.J. Pedraza J.D. Fowlkes Y.-F. Guan 《Applied Physics A: Materials Science & Processing》2003,77(2):277-284
Irradiation with polarized laser light of 248-nm wavelength induces the formation of periodic undulations ∼10-nm-highon flat
silicon substrates. The wavelength of these periodic structures is a function of the light wavelength and the angle of incidence
of the laser beam. Linear arrays of silicon nanoparticles with fairly uniform size that extended up to a millimeter were formed
if the irradiation was performed using polarized light. When non-polarized laser light with the same fluence was used to illuminate
an initially flat surface, non-aligned nanoparticle strings were obtained. However, if part of the irradiated area was microstructured,
nanoparticle linear arrays resulted in the vicinity of the microstructured region. An analysis on the evolution of these nanostructures
is presented. Nanocolumns could be grown on top of every cone of a microstructured surface upon cumulative laser irradiation
with non-polarized light, reaching a height of ∼3 μm and a diameter of 100–200 nm. The mechanisms of nanocolumn origin and
growth are analyzed.
Received: 16 December 2002 / Accepted: 20 January 2003 / Published online: 28 May 2003
RID="*"
ID="*"Corresponding author. Fax: +1-865/974-4115, E-mail: apedraza@utk.edu 相似文献
9.
M. Masuda K. Sugioka Y. Cheng N. Aoki M. Kawachi K. Shihoyama K. Toyoda H. Helvajian K. Midorikawa 《Applied Physics A: Materials Science & Processing》2003,76(5):857-860
We show that a femtosecond laser enables us to produce true three-dimensional (3-D) microstructures embedded in a photosensitive
glass, which has superior properties of transparency, hardness and chemical and thermal resistances. The photosensitivity
arises from the cerium in the glass. After exposure to a focused laser beam, latent images are written. Modified regions are
developed by a post-baking process and then preferentially etched away in a 10% dilute solution of hydrofluoric acid at room
temperature. We have measured the critical dose for modification of the photosensitive glass, and fabricated 3-D microstructures
with microcells and hollow microchannels embedded in the glass based on the critical dose.
Received: 12 August 2002 / Accepted: 13 August 2002 / Published online: 4 December 2002
RID="*"
ID="*"Corresponding author. Fax: +81-48/468-4682, E-mail: mmasudaw@postman.riken.go.jp 相似文献
10.
A. Thompson N. Nazhestkina A. Siahmakoun G. Duree N. Roesler 《Applied physics. B, Lasers and optics》2003,76(5):547-554
We present experimental investigations of electrical fixing techniques in Ce:SBN:60. The effect of crystal fatigue on the
diffraction efficiency of electrically fixed photorefractive gratings is studied. We observed that applying an ac field to
the crystal eliminated crystal fatigue and improved diffraction efficiency. A controllable diffraction efficiency of a photorefractive
grating is presented. A reproducible diffraction efficiency of up to 75% is obtained using a write-reveal grating technique
with high-voltage pulses of opposite polarity. We also show that the diffraction efficiency can be controlled by varying the
intensity of the writing beams incident to the crystal during the recording process. A method of determining the hysteresis
loop using the domain-fixing technique is proposed. The dependence of the diffraction efficiency on the direction of the applied
electric field while writing the hologram is studied. Our experiments show that, during writing, when the electric field is
applied opposite to the c axis the grating can be successfully revealed with both positive and negative dc voltages. However,
when the grating is written with a field parallel to the c axis, the grating can be revealed only with a field applied in
the opposite direction.
Received: 28 October 2002 / Revised version: 28 February 2003 / Published online: 14 May 2003
RID="*"
ID="*"Corresponding author. Fax: +1-812/872-6167, E-mail: azad.siahmakoun@rose-hulman.edu 相似文献
11.
A detailed analysis of new effects related to extremely asymmetrical scattering (EAS) of bulk and guided weakly dissipating
electromagnetic waves in oblique periodic gratings is presented. A very important role of the previously determined critical
grating width is demonstrated for EAS in dissipative gratings. Incident and scattered wave amplitudes inside and outside the
grating are analysed as functions of dissipation coefficient, grating width, grating amplitude, etc. Strong differences in
the patterns of scattering in gratings that are narrower and wider than the critical width are demonstrated and discussed.
Deep analogies between EAS and other resonant optical effects, such as attenuated total reflection, Fabry–Pérot interferometry,
etc. are revealed and discussed. A physical interpretation of the obtained results is presented.
Received: 19 February 2002 / Revised version: 28 June 2002 / Published online: 22 November 2002
RID="*"
ID="*"Corresponding author. Fax: +61-7/3864-9079, E-mail: d.gramotnev@qut.edu.au 相似文献
12.
13.
M. Yorozu J. Yang Y. Okada T. Yanagida F. Sakai S. Ito A. Endo 《Applied physics. B, Lasers and optics》2003,76(3):293-297
Polarization-dependent spatial beam profiles of femtosecond X-ray pulses generated by a laser Compton scheme were measured.
The X-ray pulses were generated by the interaction at an angle of 90° between 100-fs laser light and a 3-ps, 3π-mm mrad electron
beam. The polarization of the laser light was linear in two different directions, either parallel or perpendicular to the
electron beam axis. The measured profiles showed good agreement with theoretical results.
Received: 5 July 2002 / Revised version: 17 October 2002 / Published online: 5 February 2003
RID="*"
ID="*"Corresponding author. Fax: +81-424/684477, E-mail: msf_yorozu@shi.co.jp 相似文献
14.
K. V. Shandarova V. M. Shandarov E. V. Smirnov D. Kip M. Stepić C. Rüter 《Russian Physics Journal》2006,49(9):964-969
Special features of linear and nonlinear propagation of coherent light beams in two-dimensional photorefractive photonic lattices
optically induced in the lithium niobate crystal doped with iron are experimentally investigated. The two-dimensional gratings
are formed by consecutive recording of two one-dimensional photorefractive gratings in the crystal. Experiments were performed
using He-Ne laser irradiation with a wavelength of 633 nm.
__________
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 58–62, September, 2006. 相似文献
15.
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
16.
D. Sabourdy V. Kermène A. Desfarges-Berthelemot M. Vampouille A. Barthélémy 《Applied physics. B, Lasers and optics》2002,75(4-5):503-507
The coherent combining of two Nd:YAG lasers using a Vernier–Michelson-type cavity has been demonstrated. The spectral behaviour
and the energetic performance are reported. We firstly show that the combining efficiency is not strongly spoilt by the gain
imbalance between the two amplifying media, and secondly, that despite the interferometric nature of the cavity, the Vernier–Michelson
laser can withstand environmental perturbations without alteration in output power.
Received: 25 April 2002 / Revised version: 18 May 2002 / Published online: 25 September 2002
RID="*"
ID="*"Corresponding author. Fax: +33-5/5545-7253, E-mail: kermene@ircom.unilim.fr 相似文献
17.
Grazing-angle scattering (GAS) is a type of Bragg scattering in slanted wide periodic gratings. It occurs when the diffracted
order satisfying the Bragg condition (scattered wave) propagates at a grazing angle to the grating boundaries. Previous research
has been concerned only with first-order GAS, which has been shown to be a highly unusual type of scattering characterised
by a strong resonant increase of amplitudes of the scattered and incident waves in the grating. In this paper, a rigorous
numerical study of second-order GAS is presented for the case of bulk TE electromagnetic waves in planar holographic gratings.
A highly unusual pattern of strong resonances in the grating, which is strongly different from that for first-order GAS, is
predicted, described, and discussed. Physical interpretations of the predicted results are presented. In particular, a special
new type of eigenmodes in a slanted wide periodic grating with large amplitude is predicted. These eigenmodes are shown to
be guided by the grating alone without any conventional guiding effect in the structure. The typical field structure in such
eigenmodes is investigated and discussed.
Received: 16 September 2002 / Revised version: 4 November 2002 / Published online: 22 January 2003
RID="*"
ID="*"Corresponding author. Fax: +61-7/3864-9079, E-mail: d.pile@osa.org 相似文献
18.
High-efficiency holographic volume index gratings in DR1-dye-doped poly(methyl methacrylate) 总被引:1,自引:0,他引:1
Holographic volume index gratings with high diffraction efficiency (greater than 80%) are recorded in a thick sample of Disperse Red 1-doped poly(methyl methacrylate) with red light (647 nm), which is far away from the absorption peak (488 nm) of the material. Measurements of photoinduced birefringence and polarization holography recording confirm that the azo-dye reorientation mechanism is responsible for the grating formation. Energy coupling between the two writing beams is observed even when the incident beams have equal intensity. 相似文献
19.
J. Ihlemann S. Müller S. Puschmann D. Schäfer M. Wei J. Li P.R. Herman 《Applied Physics A: Materials Science & Processing》2003,76(5):751-753
Submicron surface-relief gratings were fabricated on fused silica by F2-laser ablation with nanosecond duration pulses from a high-resolution 157-nm optical processing system. A 157 nm wavelength
projection mask was prepared by ArF-laser ablation to form a 20-μm period grating of equal lines and spaces. A 25-fold demagnification
of the mask by a Schwarzschild objective generated gratings of an 830-nm period and a 250 nm modulation depth, as characterized
by SEM, AFM and HeNe-laser beam diffraction.
Received: 24 April 2002 / Accepted: 25 April 2002 / Published online: 4 December 2002
RID="*"
ID="*"Corresponding author. Fax: +49-551/503 599, E-mail: jihle@llg.gwdg.de 相似文献
20.
C. Mavroyannis 《Applied physics. B, Lasers and optics》2003,76(1):75-81
Analytical expressions of the spectral functions have been derived for a number of induced excitations that occur near the
difference-frequency generation in a four-level atomic system interacting with three laser fields. The spectral heights and
subnatural line widths of the induced peaks depend on the intensities of the laser fields involved. The maximum heights of
the induced peaks take positive, zero and negative values, indicating that the processes of absorption (attenuation), dark
resonance and stimulated emission (amplification) are likely to occur near the difference-frequency generation, respectively.
Received: 15 March 2002 / Revised version: 17 June 2002 / Published online: 8 January 2003
RID="*"
ID="*"Corresponding author. Fax: +1-613-954-5242 相似文献