共查询到20条相似文献,搜索用时 15 毫秒
1.
B. F. Kuntsevich 《Journal of Applied Spectroscopy》1999,66(5):726-732
The nonlinear amplitude-tuning characteristic of a CO2 laser with discharge-current modulation was investigated by mean of numerical simulation. It is shown that in the general
case the magnitude and shape of the laser response depend on the ratio between the frequency of the pump modulation and the
fundamental resonance frequency of the laser.
B. I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, 68, F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 5, pp. 640–644, September–October, 1999. 相似文献
2.
V. L. Kasyutich 《Journal of Applied Spectroscopy》1998,65(6):936-942
Results of sensitivity measurements in laser refractometric detection in a cylindrical cuvette are reported. A model of laser-beam
transmission in a capillary with a liquid is developed. The influence of the laser-beam position, capillary and liquid characteristics,
and laser power fluctuations on detection sensitivity is discussed.
Institute of Molecular and Atomic Physics of the National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072,
Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 6, pp. 894–899, November–December, 1998. 相似文献
3.
K. N. Korostik 《Journal of Applied Spectroscopy》1998,65(1):55-61
The influence of stimulated emission delay, dynamic shift in generation frequency, residual charge effect, timing jitter of
the radiation and excitation regime of an injection laser, as well as of dispersion in a fiber light guide on the data-internal
storage time in an electrooptical contour is investigated. It is found that the storage duration of an interval depends strongly
on the lifetime of nonequilibrium charge carriers, the simultaneous effect of a residual charge and jitter in an injection
laser, as well as on the dc bias current of the laser.
Belarusian State University, 4. F. Skorina Ave., Minsk, 220050, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii,
Vol. 65, No. 1, pp. 56–61, January–February, 1998. 相似文献
4.
A laser system comprising a synchronously pumped picosecond dye laser with combined cavity-distributed feedback and a two-stage
dye amplifier is described. The dependence of the laser pulse duration on the detuning of the cavity length, the pumping level
of the active medium, and the pulse number in the pulse train was investigated. It is shown that the combination of the two
types of feedback provides more than ten-fold shortening of the dye laser ultrashort pulse duration.
B. I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 1, pp. 47–55, January–February, 1998. 相似文献
5.
V. A. Dlugunovich E. A. Kruplevich Yu. A. Kurochkin V. N. Snopko 《Journal of Applied Spectroscopy》1998,65(6):973-978
The effect of a smooth surface binder film and the orientation of filler fibers of unidirectional superhigh-modulus organoplastic
on space-polarization characteristics of He−Ne laser reflected radiation is investigated.
B. I. Stepanov Institute of Physics of the National Academy of Sciences of Belarus, 68, F. Skorina Ave., Minsk, 220078, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 6, pp. 926–931, November–December, 1998. 相似文献
6.
The influence of changes in the refractive indices of the active medium and the loss modulator on the amplitude-detuning characteristic
of a CO2 laser was theoretically investigated. It is shown that at a comparatively great magnitude of sweeping the “instantaneous”
lasing frequency, the magnitude of the laser response increases not only in negative detunings, but also over a wide range
of positive detunings. The use of the procedure of changing the magnitude and sign of detuning as well as the range of sweeping
and the frequency of modulation makes it possible to realize various periodic and chaotic regimes of lasing, i.e., to exercise
control over the time and energy parameters of pulses over a very wide range.
B. I. Stepanov Institute of Physics of the Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus. Translated
from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 3, pp. 318–324, May–June, 1997. 相似文献
7.
B. F. Kuntsevich 《Journal of Applied Spectroscopy》1997,64(2):200-206
Analytical expressions have been obtained in a linear approximation for the amplitude-detuning characteristic of a CO2 laser with simultaneous modulation of two its parameters. It is shown that the value and form of the laser response can be
controlled over a wide range by way of changing the modulation frequency, the value of the detuning, and the phase difference
of the oscillations of the simultaneously modulated parameters.
B. I. Stepanov Institute of Physics of the Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus. Translated
from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 2, pp. 190–196, March–April, 1997. 相似文献
8.
We show the possibility of local spectral determination of nitrogen, oxygen, hydrogen, and carbon in solid materials with
the use of a plasma obtained on exposure of materials to laser radiation, including single laser pulses.
Institute of Molecular and Atomic Physics, National Academy of Sciences of Sciences of Belarus, 70, F. Skorina Ave., Minsk,
220072, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 4, pp. 482–485, July–August, 1998. 相似文献
9.
A nonlinear device based on nonlinear total internal reflection is suggested which provides a more than ten-fold shortening
of the laser pulse and smooth variation of the pulse duration due to double reflection from the interface between transparent
and absorbing media. Results are presented for the shape and duration of the pulse components that have been reflected and
transmitted by the interface.
B. I. Stepanov Institute of Physics, Academy of Sciences of Belarus, 70, F. Skorina Ave., 220072, Minsk, Belarus. Translated
from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 3, pp. 325–328, May–June, 1997. 相似文献
10.
The dynamics of near-surface plasma formation and the formation of an erosion plasma flame was investigated for quasi-continuous
laser radiation (λ=1.06 μm, q=0.1–10 MW/cm2, τ∼1.5 msec) acting on bismuth targets in air. The absence of low-threshold plasma formation at q<2 MW/cm2 was established and explained. Instabilities in the plasma formation were revealed and the range of laser radiation power
densities (2≤q≤4 MW/cm2) at which these instabilities take place was determined. At q≥5.4 MW/cm2, brightening of the flame was noted. The dependence of the luminescence temperature of the flame on the laser radiation power
density q was determined.
Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 1, pp. 126–133, January–February, 1998. 相似文献
11.
The effect of electromagnetically induced transparency (EIT) in a Λ-system formed by rubidium atoms contained in thin (10–60
μm) and extremely thin (0.3–5 μm) cells was studied experimentally. It was found that parameters of the EIT resonance degrade
slowly in the case where the frequency of the coupling laser is in resonance with the D
2 transition of rubidium, which enabled the registration of the EIT resonance in a record thin cell with a thickness of L = 390 nm. The specific features of EIT in extremely thin cells reveal themselves when the coupling laser has a frequency
detuning Δ from the atomic transition. In this case, the width of the EIT resonance rapidly increases upon an increase in
Δ at fixed L (an opposite effect takes place in centimeter-scale cells). It is shown that the width of the EIT resonance is inversely
proportional to L in the case of fixed large detuning Δ. The nearly tenfold broadening of the EIT resonance for large values of detuning Δ
is caused by the influence of atomic collisions with cell windows on dephasing rate of coherence. The expressions that allow
the estimation of the EIT-resonance width for various values of detuning Δ and small values of thickness L are found. 相似文献
12.
V. A. Ageev A. F. Bokhonov V. V. Zhukovskii A. A. Yankovskii 《Journal of Applied Spectroscopy》1997,64(5):683-688
We present the results of investigations undertaken to establish relationships between certain characteristics of the disintegration
of metals in air and liquid under laser radiation and their thermophysical properties, as well as between the basic parameters
of a gas cavity formed in a liquid and the energy of the laser ablation products of metals. Consideration is given to the
possibilities of applying the dynamic properties of this cavity to control the time behavior of the radiation of solid-state
lasers and to solve spectroanalytical problems.
Institute of Molecular and Atomic Physics, Academy of Sciences of Belarus, 70, F. Skorina Ave, Minsk, 220072, Belarus. Translated
from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 5, pp. 668–673, September–October, 1997. 相似文献
13.
Short-laser-pulse-driven emission of energetic ions into a solid target from a surface layer spalled by a laser prepulse 总被引:1,自引:0,他引:1
A.G. Zhidkov L.V. Zhigilei A. Sasaki T. Tajima 《Applied Physics A: Materials Science & Processing》2001,73(6):741-747
An efficient emission of picosecond bunches of energetic protons and carbon ions from a thin layer spalled from a organic
solid by a laser prepulse is demonstrated numerically. We combine the molecular dynamics technique and multi-component collisional
particle-in-cell method with plasma ionization to simulate the laser spallation and ejection of a thin (∼20–30 nm) solid layer
from an organic target and its further interaction with an intense femtosecond laser pulse. In spite of its small thickness,
a layer produced by laser spallation efficiently absorbs ultrashort laser pulses with the generation of hot electrons that
convert their energy to ion energy. The efficiency of the conversion of the laser energy to ions can be as high as 20%, and
10% to MeV ions. A transient electrostatic field created between the layer and surface of the target is up to 10 GV/cm.
Received: 13 March 2001 / Accepted: 20 March 2001 / Published online: 20 June 2001 相似文献
14.
L. Y. Min'ko A. N. Chumakov A. N. Loparev G. I. Bakanovich V. B. Avramenko 《Journal of Applied Spectroscopy》1998,65(2):273-280
It is established that, in the case of laser action on materials in large illuminated spots in atmospheric-pressure air for
a laser radiation power density q≤2 MW/cm2 (λ=1.315 μm), an evaporative regime with plane scattering of the laser-produced erosion plasma is realized while, for q≈5–17
MW/cm2, the plasma front is transferred to the air, leading to plasma screening of the target and shaping of a subsonic radiation
wave in the air. As the duration of the laser pulses increases (τ∼160 μsec), in spite of the large illuminated spots (S∼150
cm2) the evaporative regime of the laser action with plane plasma scattering goes over into a regime with jet outlow and formation
of a quasistationary shock wave.
Deceased.
Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 2, pp. 261–268, March–April, 1998. 相似文献
15.
Diagnostics of a near-surface laser plasma, the plasma of a strong-current pulse gaseous discharge in inert gases, nitrogen,
and carbon dioxide under conditions of intense evaporation of the wall of the discharge chamber, the plasma of a discharge
with a hollow cathode, and the active medium of an excimer laser was conducted by methods of intracavity laser spectroscopy
and laser-induced fluorescence. The dynamic fields and absolute concentrations of atoms, ions, molecules and electrons, the
plasma temperature, and the velocities of flows of particles were measured. The quantitative determination of the density
of particles in the erosion laser flame prior to breakdown and the phenomena associated with the formation of molecules in
the laser plasma received primary consideration.
To whom correspondence should be addressd.
Instite of Molecular and Atomic Physics of the Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 3, pp. 281–290, May–June, 1997. 相似文献
16.
V. A. Dlugunovich 《Journal of Applied Spectroscopy》1999,66(5):719-725
The degree and azimuth of polarization and the indicatrix of the intensity of radiation (λ=0.63 μm) reflected by the surface
of a monodirectional superhigh-modulus organoplastic material after structural transformations induced in it by CO2-laser radiation are measured. It is shown that the space-polarization characteristics of the radiation reflected by the organoplastic
material charred as a result of laser heating correspond to the parameters of radiation scattered by a nontransparent material
with an isotropic surface in the approximation of geometrical optics.
B. I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, 68, F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 5, pp. 635–639, September–October, 1999. 相似文献
17.
Using the methods of laser-induced fluorescence and emissive spectroscopy, we carried out investigations of the formation
of TiO molecules in a laser plasma produced by focusing the radiation of an AYG:Nd3+ laser on the surface of a titanium target in air. The radiation flux density varied within the range 108–1010 W/cm2. We investigated the distribution of molecules over internal states and the space-time distributions of Ti atoms in the ground,
metastable, and excited states, as well as of TiO molecules in the ground and excited states. We found that gas-phase reactions
with participation of Ti atoms in the ground state provide the most probable channel for the formation of TiO molecules; the
role of reagents in ionized, excited, and metastable states is of secondary importance.
Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 1, pp. 109–115, January–February, 1999. 相似文献
18.
L. P. Runets 《Journal of Applied Spectroscopy》1997,64(6):749-754
A method for determining optical density at the center of an atomic absorption line contour from the spacing between the components
of the two-frequency generation spectrum of a laser with a phase-polarization selector is suggested. It is shown that the
method makes it possible to measure the largest possible optical densities, but it is not suitable for measuring optical densities
smaller than unity. Optical densities at the center of the D-lines of sodium are measured experimentally. A good agreement
between experimental and predicted data is obtained.
Institute of Molecular and Atomic Physics of the Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 6, pp. 738–743, November–December, 1997. 相似文献
19.
For the first time, the dissipation of laser-radiation energy in the gas surrounding a target is investigated under the conditions
of intense plasma formation near a surface and the existence of large spots of: irradiation. The parameters of different regions
of the heated gas are measured and an energy balance of the process of laser effects is obtained.
Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 6, pp. 814–817, November–December, 1998. 相似文献
20.
We investigated the effect of the mode composition (longitudinal and transverse modes) of laser radiation on the basic parameters
of the stroke pattern formed on a treated surface placed inside a laser cavity. We found that the contrast of the stroke pattern
formed by a laser beam with a complex set of longitudinal modes depends, in the first place, on the width of the laser radiation
spectrum and the laser cavity length and is virtually independent of the angle of rotation of the beam. In the region of small
rotation angles the broadening of strokes caused by the effect of transverse modes becomes predominant.
B. I. Stepanov Institute of Physics, Academy of Sciences of Belarus, 70, F. Skorina Ave., Minsk, 220072, Belarus. Translated
from Zhurnal Prikaladnoi Spektroskopii, Vol. 64, No. 1, pp. 50–54, January–February, 1997. 相似文献