共查询到20条相似文献,搜索用时 15 毫秒
1.
We present results of the characterization of the nonlinear refractive index of the laser crystal Yb:KGd(WO4)2 using a z-scan technique over the 800–1600 nm wavelength range. Based on our experimental and theoretical results we conclude that Yb:KGW crystal is a good candidate for efficient Kerr-lens mode locking. PACS 42.65.An; 42.65.Hw; 42.55.Rz; 42.65.Re 相似文献
2.
Possible parametric oscillation of 3-THz pulse at synchronous pumping of the ZnGeP2 crystal by a train of short second-harmonic pulses from the CO2 laser has been analyzed. Calculation shows that at changing laser pulse duration τ between 4 and 500 ps and correspondingly pumping energy density (0.5–3.5 J cm−2) THz pulse peak power varies from 3 to 70MW with maximum at τ =9 ps. 相似文献
3.
Yu. D. Zavartsev A. I. Zagumennyi Yu. L. Kalachev S. A. Kutovoi V. A. Mikhailov I. A. Shcherbakov 《Physics of Wave Phenomena》2017,25(1):1-9
Six absorption bands of Tm3+:Sc2SiO5 crystal have been investigated by decomposing each absorption band into a series of Lorentzian peaks. Polarized light of two polarizations was transmitted in three perpendicular directions through a crystal shaped as a parallelepiped with polished faces. The results are presented in the form of tables containing the parameters of the found Lorentzian peaks: central wavelength, width, and height. 相似文献
4.
Y.V. Volk A.M. Malyarevich K.V. Yumashev V.N. Matrosov T.A. Matrosova M.I. Kupchenko 《Applied physics. B, Lasers and optics》2007,88(3):443-447
Anisotropy of the nonlinear absorption of Co2+ ions in MgAl2O4 single crystal at the wavelengths of 1.35 and 1.54 μm has been experimentally demonstrated. The experimental data are analyzed
in the framework of a phenomenological model when the Co2+ ions are described as three sets of linear dipoles oriented along the crystallographic axes. Ground-state and excited state
absorption cross-sections at 1.35 and 1.54 μm are evaluated to be σgsa=(4.0±0.3)×10-19, σesa=(3.6±0.4)×10-20 cm2 and σgsa=(5.1±0.3)×10-19, σesa=(4.6±0.4)×10-20 cm2, respectively.
PACS 42.55.Rz; 71.20.Be 相似文献
5.
V. M. Gordienko I. A. Makarov V. P. Petukhov A. S. Khomenko 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2010,4(2):183-188
The dependence of the characteristic X-ray radiation yield from CaF2 crystal on the formed microchannel depth under highly intensive (I ∼ 3 × 1015 W/cm2) laser pulses with different contrast was obtained. The maximum of the characteristic X-ray radiation yield at these experimental
conditions corresponded to the microchannel depth of 30–50 μm. The efficiency of the laser radiation conversion to the characteristic
X-ray radiation increased from 6 × 10−8 for the surface up to 10−7 in the microchannel. The dependence of the characteristic X-ray radiation yield on the viewing angle showed that the source
of X-ray radiation was located near the surface inside the microchannel. 相似文献
6.
A. V. Gloskovskii M. R. Panasyuk L. I. Yaritskaya N. K. Gloskovskaya 《Physics of the Solid State》2003,45(3):414-418
The absorption spectra and photo-and dark conductivity of the CdI2-PbI2 system are investigated in the temperature range 4.2–300 K. The temperature dependence of the photoluminescence and the IR stimulation spectra of luminescence and induced photoconductivity at 4.2 K are also studied. The results are interpreted by considering microphase inclusions of PbI2 into the CdI2 crystal lattice as activator centers. An energy-level diagram in which the narrow band of the PbI2 microphase genetically related to the metastable 3P0 level of lead plays a significant role is presented for this crystal system. 相似文献
7.
The initiation of H2/O2/H2O mixture combustion when asymmetric vibrations in H2O molecules are excited by a resonant IR laser radiation is considered. It is shown that the vibrational excitation of the molecules gives rise to new efficient channels for the formation of chemically active O and H atoms and OH radicals. As a result, the chain mechanism of combustion in the mixtures is enhanced and, as a consequence, the induction time is cut and the ignition temperature is lowered. Even at a minor radiant energy flux delivered to the gas (Ein≈2.5 J/cm2), the ignition temperature of the stoichiometric H2/O2 mixture containing only 5% of H2O may become as low as 300 K. 相似文献
8.
Yu. A. Kotov V. V. Osipov O. M. Samatov M. G. Ivanov V. V. Platonov A. M. Murzakaev E. I. Azarkevich A. I. Medvedev A. K. Shtolts O. R. Timoshenkova 《Technical Physics》2004,49(3):352-357
The characteristics (phase composition, grain shape, grain size distribution, and specific surface area) of Ce0.78Gd0.22O2-δ nanopowders produced by exposing the target to pulsed CO2 laser radiation are reported. Reasons for a threefold increase in the output of the experimental powder-preparation unit
(up to 60 g/h) with the characteristic grain size (≈10 nm) remaining unchanged are discussed. 相似文献
9.
P. A. Popov S. A. Skrobov N. V. Mitroshenkov V. N. Shlegel’ V. D. Grigor’eva 《Physics of the Solid State》2016,58(8):1716-1718
The thermal conductivity of Na2W2O7 single crystal has been studied along the main crystallographic directions at temperatures of 50–573 K. A low thermal conductivity is found to correlate with a significant difference in the cation weight. 相似文献
10.
The effect of resonator length on ZnGeP2 doubly resonant optical parametric oscillator was reported in this letter. With the employment of a Tm,Ho:GdVO4 laser as the pump source at 2.05 μm, we have found that there are obvious peaks of the output power when the resonator lengths
are matched to the length of the pump source. The ZGP OPO can generate a maximum output power of 4.27 W at 3.80 μm signal
and 4.45 μm idler when the resonator length matches that of the pump source. 相似文献
11.
The nonlinear microwave absorption in the (CH3NH3)2CuBr4 antiferromagnetic crystal is investigated experimentally. The temperature and angular dependences of the parameters of nonlinear resonance and the dependences of these parameters on the microwave pump power are analyzed. It is found that the nonlinear properties deteriorate with decreasing temperature and the linear and nonlinear contributions are competitive in character. 相似文献
12.
The magnetic properties of (CH3NH3)2CuBr4 quasi-two-dimensional crystals were studied experimentally. The magnetic-field and temperature dependences of magnetization were measured for various magnetic field orientations relative to the crystallographic axes. Possible reasons for features in the behavior of the magnetization are discussed. 相似文献
13.
Using a very simple and straightforward approach we derive the condition to be satisfied for achieving wavelength-insensitive broadband phase matching in a type-I noncollinear optical parametric amplifier (NOPA), required for the generation of ultra-fast laser radiation. Nonlinear optical properties of a relatively newly grown crystal Li2B4O7 (LB4) have also been studied and we found that this crystal satisfies the condition required to realize the broadband phase matching and is suited for the generation of tunable visible–near-infrared ultra-fast laser radiation employed in a 395-nm-pumped type-I NOPA. The phase-matching bandwidths of type-I NOPAs in different borate-group crystals, such as BBO, CLBO, and KABO, are also numerically estimated. The values are 157, 164, 152, and 174 THz for 1-mm-thick BBO, CLBO, KABO, and LB4 crystals, with the noncollinear angles between the input pump and the signal beams 3.7°, 3.0°, 3.4°, and 2.9°, respectively, for the signal wavelengths centered at 630 nm. In addition to the largest bandwidth, LB4 crystal has several other attractive properties to be used in optical parametric applications, such as high laser damage threshold, wide optical transmission, easy crystal growth to excellent optical quality with large sizes, easy treatment of cutting and polishing, and nonhygroscopicity. PACS 42.65.Yj; 42.65.Re; 42.70.Mp 相似文献
14.
S. V. Mel’nikova L. I. Isaenko V. M. Pashkov I. V. Pevnev 《Physics of the Solid State》2005,47(2):332-336
Crystals of the KPb2Br5compound are investigated using polarized light microscopy and calorimetry. The birefringence and the angle of rotation of the optical indicatrix are measured in the temperature range 270–620 K. It is found that the KPb2Br5 crystal undergoes a first-order ferroelastic phase transition at temperatures T0↑ = 519.5 K and T0↓ = 518.5 K with a change in the enthalpy ΔH = 1300 ± 200 J/mol. This transition is accompanied by both twinning and the symmetry change mmm ? P21/c. It is revealed that the angle of rotation of the optical indicatrix exhibits an unusual behavior under variations in the temperature due to a strong temperature dependence of the birefringence. 相似文献
15.
A.E. Troshin V.E. Kisel A.S. Yasukevich N.V. Kuleshov A.A. Pavlyuk E.B. Dunina A.A. Kornienko 《Applied physics. B, Lasers and optics》2007,86(2):287-292
The polarized absorption spectra of Tm3+-doped potassium yttrium tungstate (Tm:KY(WO4)2) crystal at room temperature were measured. The emission spectrum and lifetime of the 3
F
4 excited state were determined. Using standard and modified Judd–Ofelt theories, the intensity parameters and the radiative
lifetimes were calculated and good agreement with the experimental results was obtained for both theories. Continuous-wave
laser operation in Tm:KYW crystal under laser diode pumping at 802 nm and 1750 nm was demonstrated with slope efficiency of
53% and 28% and output power of about 555 mW and 86 mW, respectively.
PACS 42.55.Xi; 42.60.Pk; 42.70.Hj 相似文献
16.
M. Delaigue V. Jubera J. Sablayrolles J.-P. Chaminade A. Garcia I. Manek-Hönninger 《Applied physics. B, Lasers and optics》2007,87(4):693-696
We report for the first time pulsed laser operation of the Yb-doped Li6Y(BO3)3 (Yb-LYB) crystal in the nanosecond as well as in the femtosecond regime. Pulse durations as short as 355 fs have been obtained
in passively mode-locked operation and pulse energies up to 140 μJ in Q-switched operation.
PACS 42.70Hj; 42.55Xi; 42.60Gd; 42.65Re 相似文献
17.
In this paper, a detailed theoretical analysis of the second-harmonic generation (SHG) efficiency as a function of polarization ratio and crystal length of CsLiB6O10 (CLBO) in the phase matching using a computer simulation is presented. The SHG efficiency was as high as 80% when the pumping radiation was a plane wave. The efficiency is 65% and 80% for the pumping waves of type I and type II Gaussian beams, respectively. An important result is that the phase matching of type II is perfectly adopted in the SHG experiment with CLBO. 相似文献
18.
Thermal lensing has been studied by a probe beam technique in flashlamp-pumped Nd:KGdW laser rods with rod axes positioned
in the N
p–N
g plane and making different angles with the N
g optical indicatrix axis. It was found that the orientation of principal meridional planes of the astigmatic thermal lens
in Nd:KGdW corresponds to the directions with maximum and minimum values of thermal-expansion coefficient in the plane perpendicular
to the rod axis. The athermal Nd:KGdW laser crystal orientation defined as orientation with weak positive near spherical thermal
lens has been determined to make an angle of 30○–40○ with the N
g axis for light polarization E∥N
m. 相似文献
19.
The results of x-ray structural studies of the [N(C2H5)4]2CdBr4 crystal at low temperatures are presented. The unit cell parameters and the thermal expansion coefficients along the main crystallographic directions are measured at temperatures in the range from 90 to 320 K. The integrated intensities of the diffraction reflections are investigated as a function of the temperature. It is shown that the curves a = f(T), c = f(T), I 500 = f(T), and I 006 = f(T) at temperatures T 1 ≈ 174 K and T 2 ≈ 226 K exhibit anomalies in the form of abrupt changes in the lattice parameters and the diffraction reflection intensities. This indicates that the [N(C2H5)4]2CdBr4 crystal undergo phase transitions at these temperatures. Moreover, there is an anomaly in the form of a small maximum at the temperature T 3 = 293 K. 相似文献
20.
L. N. Korotkov T. N. Korotkova R. R. Levitskii S. I. Sorokov A. S. Vdovych 《Bulletin of the Russian Academy of Sciences: Physics》2011,75(10):1331-1334
The time dependences of polarization of K0.88(NH4)0.12H2PO4 mixed crystal have been studied within the temperature range of 74–100 K. Two mechanisms of polarization relaxation were
found. The first mechanism is caused by domain walls lateral motion and their interaction with point lattice defects. The
second one supposedly is due to polar regions infiltration through the regions of frustrated paraelectric phase. 相似文献