共查询到20条相似文献,搜索用时 0 毫秒
1.
R.W. Kempf P.T. Wilson J.D. Canterbury E.D. Mishina O.A. Aktsipetrov M.C. Downer 《Applied physics. B, Lasers and optics》1999,68(3):325-332
2 and Si(110)-SiO2 interfaces and DC-electric-field induced TH and FH generation is then observed in Si(111)-SiO2-Cr and Si(110)-SiO2-Cr MOS structures for the first time. A systematic phenomenological analysis of azimuthal anisotropy of TH and FH generation
intensity is performed for (111) and (110) surfaces of Oh symmetric single crystals. A phenomenological model of electro-induced effects in TH and FH generation is then developed
and the surface specificity and sensitivity of TH and FH generation are discussed. Optical interference of surface electro-induced
and bulk bias-independent contributions to the effective third-order nonlinear polarization is proposed as the mechanism underlying
surface sensitivity of electro-modulated TH probe.
Received: 16 October 1998 相似文献
2.
B. Koopmans A. M. Janner H. A. Wierenga Th. Rasing G. A. Sawatzky F. van der Woude 《Applied Physics A: Materials Science & Processing》1995,60(2):103-111
We discuss the separation problem of bulk vs interface contributions in optical Second-Harmonic Generation (SHG). A new method is presented, which — in special cases — provides a full separation of all interface and bulk tensor components. The method is based on measurements in a thin-film geometry, and the relation between two bulk tensor components obtained from group-theoretical arguments. The separation problem in its strict sense is shown to be absent in Magnetization-induced SHG (MSHG). Though, in practice, also in the MSHG case interface and bulk contributions can be closely resemblant. The approach is illustrated by second-harmonic experiments on C60 thin films. SHG in this system is found to be completely dominated by bulk processes.Paper presented at the 129th WE-Heraeus-Seminar on Surface Studies by Nonlinear Laser Spectroscopies, Kassel, Germany, May 30 to June 1, 1994 相似文献
3.
V. Venkataramanan K. Noguchi M. Aono T. Suzuki 《Applied physics. B, Lasers and optics》2002,74(7-8):683-689
We describe the instrumentation related to the first observation of magnetization-induced enhancement of surface second-harmonic
generation (SHG) from the paramagnetic Si(111)-7×7 surfaces. A judicious choice of polarization and sample orientation enabled
us to isolate the magnetic-field-dependent tensor element of the nonlinear susceptibility. A conductive liquid-nitrogen system,
coupled to an ultrahigh-vacuum system that is immune to the high magnetic field of 10 T, cooled the sample to about 120 K.
A high extinction that is necessary to detect the magnetization-induced SHG (MSHG) was accomplished by minimizing stray optical
effects such as Faraday rotation, photoluminescence and thermal birefringence in all optical components, with extra care taken
for the UHV window. Consistent and stable operation of this sensitive measurement system permitted experiments involving MSHG
at multiple wavelengths and temperatures. Probing the magnetization-induced optical nonlinearity was validated by quenching
the surface states by oxidation of the surface layers. From MSHG measurements at two wavelengths resonant with different surface-state
transitions, we were able to suggest that the observed MSHG is proportional to the number of dangling bond states of Si(111)-7×7.
Received: 15 January 2002 / Published online: 2 May 2002 相似文献
4.
T. Rasing 《Applied Physics A: Materials Science & Processing》1994,59(5):531-536
Optical Second-Harmonic Generation (SHG) has been used to study the technologically very important buried semiconductor-metal and magnetic multilayer interfaces. For the case of GaAs-Au, the SHG intensity is shown to depend on the applied bias and Schottky barrier height, and is strongly affected by the sweepout of the carriers generated by the fs excitation pulses. For the M/Co/M multilayers, with M=Cu or Au, the SHG signals appear to depend strongly on the magnetization and can be shown to be interface specific.Paper presented at the 129th WE-Heraeus-Seminar on Surface Studies by Nonlinear Laser Spectroscopies, Kassel, Germany, May 30 to June 1, 1994 相似文献
5.
Second-harmonic generation (SHG) results for Ni and Co films on Cu (001) have been reinvestigated regarding the depth sensitivity
of this technique for thin films. We find that tangential components of the nonlinear susceptibility are much more sensitive
to real film properties than normal components, which are confined to surfaces and interfaces. In consequence, for SHG experiments
on ultra-thin metal films, polarization combinations should be favored that possess only tangential susceptibility components,
even though the yield is weaker. Additional phase measurements are necessary to obtain full information about the film.
Received: 20 January 2002 / Published online: 6 June 2002 相似文献
6.
A. Melnikov O. Krupin U. Bovensiepen K. Starke M. Wolf E. Matthias 《Applied physics. B, Lasers and optics》2002,74(7-8):723-727
The magnetization of 10-nm Gd films on W (110) has been investigated with second-harmonic generation (SHG). We observed a
strong second-harmonic (SH) yield, which we attribute to resonance enhancement by the well-known Gd (0001) d-like surface
state above the Fermi level. Since this state is spin-polarized it enhances the magnetic SHG contrast. The contrast, the relative
phase between odd and even SH fields, and the amplitude ratio of these fields depend strongly on wavelength, which confirms
the resonance enhancement. Further proof is provided by the fact that oxidation of the Gd surface reduces the SH yield by
an order of magnitude.
Received: 16 October 2001 / Revised version: 21 March 2002 / Published online: 11 June 2002 相似文献
7.
Y.G. Fokin T.V. Murzina O.A. Aktsipetrov S. Soria G. Marowsky 《Applied physics. B, Lasers and optics》2002,74(7-8):777-781
Ferroelectric properties of thin (1.5–4 μm planar cells of a ferroelectric liquid crystal (FLC) mixture are studied using
electro-optic measurements, second-harmonic generation (SHG) and SHG interferometry. A switching behaviour of the FLC cells
in external dc electric fields is observed. It is characterised by rotation of the polarisation plane of the transmitted light
and by changes in the SHG intensity, phase and anisotropy dependences, which are attributed to a collective motion of the
system as a ferroelectric uniform state with C2 symmetry.
Received: 16 October 2001 / Revised version: 18 March 2002 / Published online: 6 June 2002 相似文献
8.
L.A. Golovan V.Yu. Timoshenko A.B. Fedotov L.P. Kuznetsova D.A. Sidorov-Biryukov P.K. Kashkarov A.M. Zheltikov D. Kovalev N. Künzner E. Gross J. Diener G. Polisski F. Koch 《Applied physics. B, Lasers and optics》2001,73(1):31-34
Optical second-harmonic generation is investigated in free-standing (110) porous silicon films having strong in-plane birefringence.
Based on the measured values of the refractive indices, the conditions of phase matching are calculated and verified in the
experiments on angular and polarization dependences of second-harmonic generation. Filling pores with a transparent dielectric
liquid allows phase matching to be achieved and the second-harmonic signal to be increased by two orders of magnitude. The
results of these experiments suggest an opportunity to form new-type nonlinear-optical media consisting of birefringent porous
silicon as a phase-matching matrix for the materials embedded in the pores.
Received: 30 April 2001 / Published online: 7 June 2001 相似文献
9.
N. Arzate J.E. Mejía B.S. Mendoza R. Del Sole 《Applied physics. B, Lasers and optics》1999,68(3):629-632
1 resonances for clean and H covered surfaces shift as a function of the dc field in agreement with experiment. This suggests
the presence of built-in electric fields whose strength depends on the H coverage, and which are strongly localized in the
subsurface region.
Received: 20 September 1998 相似文献
10.
11.
Received: 22 November 1998 相似文献
12.
An analytical function involving four parameters is proposed to express the second-harmonic generation efficiency as well
as the parametric generation gain coefficient in the Boyd–Kleinman theory. The analytical function clearly reveals the dependence
of conversion efficiency on the focusing parameter and the walk-off parameter. Moreover, the optimum focusing parameter and
its corresponding maximum efficiency are explicitly given in the analytical function, leading to a straightforward evaluation
of a given crystal performance.
Received: 20 January 2003 / Published online: 22 May 2003
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ID="*"Corresponding author. Fax: +886-35/7291-34, E-mail: yfchen@cc.nctu.edu.tw 相似文献
13.
W. Cheikh-Rouhou L.C. Sampaio B. Bartenlian P. Beauvillain A. Brun J. Ferré P. Georges J.-P. Jamet V. Mathet A. Stupakewicz 《Applied physics. B, Lasers and optics》2002,74(7-8):665-670
The optical and magneto-optical second harmonic reflectivity response of Au/Co/Au/Cu multilayers grown on vicinal Si (111)
substrates has been studied. These azimuthal optical non-linear experiments check the uniaxial character of the crystallinity
of the Au buffer layer and the magnetic behavior of the ultrathin Co films in the metallic multilayer. They clearly show the
strong dependence of the growth parameters and the misorientation of the vicinal surface on the SHG reflectivity signals.
This uniaxial behavior is also correlated to linear MOKE experiments on the magnetic anisotropy with an easy magnetization
axis parallel to the step edges.
Received: 16 October 2001 / Published online: 29 May 2002 相似文献
14.
J.I. Dadap J. Shan A.S. Weling J.A. Misewich T.F. Heinz 《Applied physics. B, Lasers and optics》1999,68(3):333-341
Received: 16 December 1998 相似文献
15.
Using the effective-field theory we studied the magnetic properties of a random diluted spin-1/2, 1, 3/2 superlattice which consists of three different ferromagnetic materials. The critical temperature of the system is studied as a function of the concentration of magnetic atoms and exchange interactions in each layer. The temperature dependence of magnetization shows that the properties of the diluted system are different from those of the corresponding pure system. 相似文献
16.
Received: 21 December 1998 相似文献
17.
Second-harmonic generation (SHG) in atmospheric-pressure air is experimentally studied using single focused linear-polarized
Ti:sapphire intense femtosecond laser pulses at 810 nm. The efficiency of SHG is found to reach a maximum at the optical breakdown
threshold of ≈2.9×1014 W/cm2. The spectral distribution and polarization property of the second harmonic are investigated. The contribution to SHG from
electric-field-induced third-order mixing plays the main role even after the optical breakdown had occurred.
Received: 23 May 2000 / Published online: 16 August 2000 相似文献
18.
Nonlinear magneto-optical probing of magnetic interfaces 总被引:1,自引:0,他引:1
T. Rasing 《Applied physics. B, Lasers and optics》1999,68(3):477-484
Received: 16 October 1998 相似文献
19.
C. Tomas E. Vinet J.-P. Girardeau-Montaut 《Applied Physics A: Materials Science & Processing》1999,68(3):315-320
Received: 1 October 1998 / Accepted: 30 October 1998 相似文献
20.
K. Pedersen T.B. Kristensen T.G. Pedersen P. Morgen Z. Li S.V. Hoffmann 《Applied physics. B, Lasers and optics》2002,74(7-8):677-682
Thin noble metal films (Ag, Au and Cu) on Si (111) have been investigated by optical second-harmonic generation (SHG) in combination
with synchrotron radiation photoemission spectroscopy. The valence band spectra of Ag films show a quantization of the sp-band
in the 4-eV energy range from the Fermi level down to the onset of the d-bands. For Cu and Au the corresponding energy range
is much narrower and quantization effects are less visible. Quantization effects in SHG are observed as oscillations in the
signal as a function of film thickness. The oscillations are strongest for Ag and less pronounced for Cu, in agreement with
valence band photoemission spectra. In the case of Au, a reacted layer floating on top of the Au film masks the observation
of quantum well levels by photoemission. However, SHG shows a well-developed quantization of levels in the Au film below the
reacted layer. For Ag films, the relation between film thickness and photon energy of the SHG resonances indicates different
types of resonances, some of which involve both quantum well and substrate states.
Received: 16 October 2001 / Revised version: 14 March 2002 / Published online: 29 May 2002 相似文献