共查询到20条相似文献,搜索用时 46 毫秒
1.
R. A. Ganeev A. I. Ryasnyanskiĭ R. I. Tugushev M. K. Kodirov F. R. Akhmedzhanov T. Usmanov 《Optics and Spectroscopy》2004,96(4):526-531
The processes of nonlinear refraction and nonlinear absorption are studied in the photorefractive Bi12SiO20 (BSO) and Bi12GeO20 (BGO) crystals at a wavelength of a picosecond Nd:YAG laser of 1064 nm. The nonlinear refraction in the crystals is shown to be related to the Kerr effect, and the nonlinear absorption at this wavelength, to three-photon absorption. The three-photon absorption coefficients of the BSO and BGO crystals are equal, respectively, to (2.5±0.8) ×10?20 and (4.4±1.3) ×10?20 cm3W?2. 相似文献
2.
A. Marrakchi J. P. Huignard P. Günter 《Applied Physics A: Materials Science & Processing》1981,24(2):131-138
The diffraction efficiency and energy transfer are investigated in photorefractive Bi12SiO20 crystals (BSO). Dependence on fringe spacing, electric fields, light intensity and rise-time constants are reported. The
optimum crystallographic orientation for each effect is determined for vertical polarization of the recording beams. It is
shown that beam coupling is a very sensitive phenomenon in BSO crystals where charge transport lengths are equivalent to usual
fringe spacings. Experimental results are interpreted on the basis of the nonlinear theory of self-diffraction developed by
Kukhtarev et al. [10]. 相似文献
3.
The influence of doping of Bi12SiO20 (BSO) with chromium and manganese ions on the thermal depolarization currents (TDCs) is investigated. Measurements are performed
in the temperature interval 300–800 K as the preliminary polarization temperature is varied in the range T
p=300–523 K. It is shown that doping significantly alters the structure of the TDC spectra. The Cr and Mn ions produce a set
of new peaks over the entire investigated temperature range. The thermal activation energies are 0.85–1.98 eV (BSO:Cr) and
0.58–1.72 eV (BSO:Mn). Another consequence of doping is an increase in the amplitudes of the peaks and the charge accumulated
during preliminary polarization.
Fiz. Tverd. Tela (St. Petersburg) 40, 472–474 (March 1998) 相似文献
4.
A. I. Ryasnyanskii 《Journal of Applied Spectroscopy》2004,71(2):295-298
The possibility of optical limitation of picosecond laser radiation in photorefractive Bi12SiO20 (BSO) and Bi12GeO20 (BGO) crystals at a wavelength of 1064 nm has been demonstrated. It is shown that the mechanism determining the process of optical limitation is three-photon absorption. The coefficients of three-photon absorption have been determined by the Z-scanning method. 相似文献
5.
T. V. Panchenko 《Physics of the Solid State》1998,40(7):1135-1139
Temperature dependences of the optical absorption of BSO:Cu crystals were investigated at photon energies between 1.36 and
3.46 eV and temperatures between 85 and 700 K. These dependences are analyzed for the energy model of a partially compensated
p-type semiconductor taking into account the temperature dependence of the concentration of shallow and deep ionized acceptors.
Fiz. Tverd. Tela (St. Petersburg) 40, 1246–1251 (July 1998) 相似文献
6.
A. T. Efremidis N. C. Deliolanis C. Manolikas E. D. Vanidhis 《Applied physics. B, Lasers and optics》2009,95(3):467-473
The photorefractive crystals of the sillenite family (Bi12SiO20 or BSO, Bi12GeO20 or BGO, and Bi12TiO20 or BTO) that belong to the cubic 23 point group are optically active, and exhibit the piezoelectric, elasto-optic, electro-optic
and electrogyration effect. In this paper we measure the dispersion of the electro-optic coefficient for all the crystals
of the sillenite family in the visible spectral range (500–800 nm). For this we measure by ellipsometry the polarization properties
of a beam transmitted in the transverse configuration under the action of an externally applied field. The experimental data
are fitted with an analytical expression of the beam polarization to find the electro-optic coefficient. The results show
a normal dispersion of the electro-optic coefficient in all three sillenite crystals, similarly to other electro-optic crystals. 相似文献
7.
B.I. Sturman A.S. Gorkunova K.H. Ringhofer 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,23(2):291-297
We investigate analytically and numerically the influence of the type of the photorefractive nonlinear response on the periodic
states (attractors) which occur during feedback controlled 2W-coupling and correspond to almost 100% diffraction efficiency
of the dynamic index grating. In addition to the case of the local response typical, for example, for LiNbO3 crystals we consider the cases of nonlocal (diffusive) response (BaTiO3, SBN) and resonant response (DC-biased BSO, BTO, and BGO crystals). It is shown that the conditions for the transition to
the periodic states and their apparent characteristics are strongly different for the two limiting cases above.
Received 16 July 2002 / Received in final form 29 October 2002 Published online 4 March 2003 相似文献
8.
S. Nagao P. Mele K. Matsumoto A. Ichinose M. Mukaida Y. Yoshida S. Horii R. Kita 《Physica C: Superconductivity and its Applications》2010,470(20):1304-1307
We report the microstructure change of BaSnO3 (BSO)–YBa2Cu3O7−x (YBCO) thin film system grown on SrTiO3 single crystal substrates by pulsed laser deposition with using the “surface-modified-target” and “mixture-target” methods. Although it was confirmed that the thick BSO nanorods incorporated to YBCO films act as strong artificial pinning centers, the formation mechanism of the nanorods is still unclear. The purpose of this work is to extend the structural investigation to higher contents of BSO (up to 71 vol.%) in order to enlighten the relationship among interfacial energy, morphology and pinning performance in binary BSO–YBCO films. 相似文献
9.
O.A. Yeshchenko M.M. Biliy Z.Z. Yanchuk 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,28(1):37-43
Excitonic absorption, reflection and photoluminescence spectra of mixed Zn(P1-xAsx)2 crystals over the full range of x ( 0 ?
x
? 1) and Zn1-xCdxP2 crystals at 0 ?
x
? 0.05 have been studied at low temperatures (1.8 K). The decrease of the energy gap in Zn(P1-xAsx)2 at the increase of x occurs slightly sublinearly. The rydbergs of excitonic series in this crystals decrease as well, and the dependences Ry
(
x
) for all series are strongly superlinear at small x. In Zn1-xCdxP2 crystals the energy gap and rydbergs decrease at the increase of x (at 0 ?
x
? 0.05) as well. The dependences of Eg and Ry on x are considerably stronger in Zn(P1-xAsx)2 than in Zn1-xCdxP2. At the increase of x the half-width of excitonic absorption lines increases monotonically in both type crystals that is evidence of the increasing
role of fluctuations of crystal potential.
Received 13 March 2002 Published online 9 July 2002 相似文献
10.
E. V. Alieva G. N. Zhizhin L. A. Kuzik V. A. Yakovlev 《Physics of the Solid State》1998,40(2):213-216
First observation of excitation of surface electromagnetic waves (SEW) is reported in the reststrahlen region in for biaxial
crystal KTiOPO4 (KTP) using a tunable CO2 laser around 10 μm, and for CaF2, BaF2, MgO (cubic crystals), and LiNbO3 (uniaxial crystal) in the far IR using ith a free-electron laser. The parameters of SEW propagation in these crystals have
been obtained by the interference method of SEW phase spectroscopy, and the possibility of determining the complex dielectric
permittivity of crystals from the SEW propagation parameters demonstrated in the range of SEW existence.
Fiz. Tverd. Tela (St. Petersburg) 40, 237–241 (February 1998) 相似文献
11.
K.P. Ko R.K. Ko S.H. Moon S.S. Oh S.I. Yoo 《Physica C: Superconductivity and its Applications》2010,470(20):1275-1279
We report a successful fabrication of c-axis oriented GdBa2Cu3O7−δ (GdBCO) films on the BaSnO3 (BSO) buffer layers on ion-beam assisted deposition (IBAD)-MgO template by pulsed-laser deposition (PLD). The (0 0 l) growth and in-plane textures of BSO buffer layers were found sensitive to the substrate temperature (Ts). With increasing the BSO layer thickness up to ∼165 nm, in-plane texture (Δ? ∼ 6.2°) of BSO layers was almost unaltered while completely c-axis oriented BSO layers were obtainable from samples with the thickness below ∼45 nm. On the BSO buffer layers showing in-plane texture of 6.2° and RMS surface roughness of ∼8.6 nm, GdBCO films were deposited at 780–800 °C. All GdBCO films exhibited Δ? values of 4.6–4.7°, Tc,zero of ∼91 K, and critical current density (Jc) over 1 MA/cm2 at 77 K in a self-field. The highest Jc value of 1.82 MA/cm2 (Ic of 51 A/cm-width) was achieved from the GdBCO film deposited at Ts of 790 °C. These results support that BSO can be a promising buffer layer on the IBAD-MgO template for obtaining high-Jc GdBCO coated conductors. 相似文献
12.
Slawomir M. Kaczmarek Lucyna Macalik Hubert Fuks Grzegorz Leniec Tomasz Skibiński Jerzy Hanuza 《Central European Journal of Physics》2012,10(2):492-499
Well oriented KYb(WO4)2 and KTb0.2Yb0.8(WO4)2 single crystals have been investigated for their magnetic and optical properties using the Raman and EPR techniques. The
registered EPR signal is dominated by three lines ascribed to ytterbium ions: one main and two satellites. Tb ions, although
non-paramagnetic, distinctly modify magnetic properties of the KYb(WO4)2 single crystal. Basic parameters of the spin Hamiltonian, including Zeeman and hyperfine terms (g and A matrices) as well the spatial orientation between principal and crystallographic axes systems were determined for both crystals. 相似文献
13.
The mechanisms of random anisotropy produced by an an effective coupling between rare-earth ion moments and orbital momenta
of Cu2+ ions through spin fluctuations is studied in R2CuO4 crystals. The effective random-anisotropy fields are estimated from an analysis of experimental data for R2CuO4 crystals (R=Eu, Pr, Gd).
Fiz. Tverd. Tela (St. Petersburg) 41, 1259–1263 (July 1999) 相似文献
14.
N. Bouarissa 《The European Physical Journal B - Condensed Matter and Complex Systems》2003,32(2):139-143
Pseudopotential investigation of energy band gaps and charge distribution in quasi-binary (GaSb)1-x(InAs)x crystals has been reported. To the best of our knowledge, there had been no reported theoretical work on these materials.
In agreement with experiment, the quasi-binary crystals of interest showed a significant narrowing of the optical band gap
compared to the conventional GaxIn1-xAsySb1-y quaternary alloys (with x
= 1 -
y). Moreover, the absorption at the optical gaps indicated that (GaSb)1-x(InAs)x is a direct Γ to Γ band-gap semiconductor within a whole range of the x composition. The information derived from the present study predicts that the band gaps cross very important technological
spectral regions and could be useful for thermophotovoltaic applications.
Received 30 August 2002 Published online 1st April 2003
RID="a"
ID="a"Present address: Physics Department, University of M'sila, 28000 M'sila, Algeria e-mail: N_Bouarissa@yahoo.fr 相似文献
15.
E. M. Zub 《Physics of the Solid State》1997,39(8):1297-1298
The x-ray diffraction spectra of Li2B4O7 single crystals are investigated in the temperature range 80–300 K, and the lattice parameter c is determined in the same temperature range in the presence of a periodically varying temperature field. An incommensurate
phase is not observed anywhere in the temperature range investigated, regardless of whether the crystals are subjected to
a periodic temperature field.
Fiz. Tverd. Tela (St. Petersburg) 39, 1461–1463 (August 1997) 相似文献
16.
A combination of the solution-melt method and solid-phase synthesis of complex oxides has been used to obtain crystals of
Bi2Sr2CaCu2O8 (2212). Partial substitution of bismuth by lead leads to a change in the orientation of the growth layers in the (001) plane
of the 2212 crystal which has an orthorhombic lattice. An increase in the dimensions is noted along with an enhancement of
the quality of the crystals when lead is introduced into the composition of the precursors.
Fiz. Tverd. Tela (St. Petersburg) 39, 219–221 (February 1997) 相似文献
17.
The drift mobility of photogenerated electrons and holes in Bi12GeO20 crystals with different degrees of doping is investigated experimentally.
Fiz. Tverd. Tela (St. Petersburg) 40, 2054–2055 (November 1998) 相似文献
18.
The influence of laser irradiation on the photoluminescence spectra of perfect C60 crystals in the orientationally disordered phase is investigated. It is shown that irradiation of the crystals with low-power
light for short durations at T=200 K produces radical changes in the luminescence spectrum. The pressure dependences of the spectral bands of the phototransformed
and initial (without irradiation) spectra differ significantly, indicating a photoinduced structural transformation of the
X centers responsible for the luminescence of C60. The phototransformed C60 crystals are stable against further exposure to light irradiation and pressure.
Pis’ma Zh. éksp. Teor. Fiz. 70, No. 12, 784–788 (25 December 1999)
Deceased. 相似文献
19.
We propose a method to visualize a phase object using a locally-controllable image amplification scheme we developed earlier which is based on two-wave coupling in a bismuth silicon oxide (Bi12SiO20, or BSO) crystal. In this method the BSO crystal is used as a phase plate in the configuration of Zernike’s phase contrast imaging system. The principle of the phase-visualization with two-wave coupling is presented. An experimental result to verify the proposed method is shown. 相似文献
20.
I. Sh. Akhmadullin V. A. Golenishchev-Kutuzov S. A. Migachev 《Physics of the Solid State》1998,40(6):1012-1018
A model is proposed for photo-and thermally induced processes in lithium niobate crystals. The model is based on the presence
of structural defects formed as a result of departure of the crystal composition from stoichiometry. Defects of the type NbLi-NbLi are introduced and the influence of oxidation-reduction heat treatment on the optical characteristics of the crystals is
analyzed.
Fiz. Tverd. Tela (St. Petersburg) 40, 1109–1116 (June 1998) 相似文献