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1.
We carried out measurements of the spectral distribution of wideband dye laser generation intensity within the limits and
in the vicinity of an absorption line with its simultaneous recording at the frequencies of the fundamental and second harmonics
of laser radiation. In the laser cavity we placed optical cuvettes with active and absorbing media, as well as selecting and
nonlinear-optical elements. We show that at double frequencies the contrast of the narrow-band hole in the multimode laser
generation spectrum increases. The gain in the concentration sensitivity of measurements depends in this case on the value
of the absorption coefficient being determined.
Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, 70, F. Skorina Ave., 220072, Minsk, Belarus.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 4, pp. 516–521, July–August, 1998. 相似文献
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冯贤平 《原子与分子物理学报》2005,22(1):30-33
本文的基本思想是设计双层金铝薄膜靶以检测激光脉冲宽度与等离子体消融深度的关系,找出有效的等离子体加热方法以产生更强更亮的等离子体辐射源.由于有预脉冲激光的存在,表层金薄膜首先被消融,由主脉冲携带的大能量就能较易穿过表层金等离子体将能量聚焦在内层铝靶上,由此产生内层高温等离子体.又由于外层低温等离子体存在,其将有效的阻碍内高温等离子体因膨胀而引起的能量损失.对无预脉冲而言,直接入射激光能量都沉积在靶表层形成表层高温等离子体.但是激光直接入射而产生的等离子体辐射总强度只比由预脉冲情况下产生的金等离子体辐射强度增加15%.而预脉冲能量只占激光总能量的2%.实验结果显示Al光谱线主要来自类氢,类氦离子跃迁.Au等离子体光谱线主要来自它的N带,O带和P带谱.我们也观察到一个明显的软X射线短波发射极限.所有结果显示由于预脉冲的存在将对靶各层等离子体辐射产生极大的影响 相似文献
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本文利用高重复频率,高平均功率大模场面积飞秒光纤激光器作为同步抽运源,抽运以多周期极化掺氧化镁铌酸锂为非线性晶体的单共振光学参量振荡器,获得了高功率可调谐红光至中红外光,信号光调谐范围为1450—2200 nm,闲频光调谐范围为2250—4000 nm,在2 W的抽运功率下,信号光输出波长为1502 nm时获得最大输出功率374 mW,转换效率为18.7%,脉冲宽度为144 fs,此时中红外输出中心波长为3.4μm,平均功率为166 mW.再利用BBO晶体对信号光进行腔内和频,获得和频光输出波长调谐范围为610—668 nm,在4.1 W抽运的情况下,最高平均功率为615 nm处的694 mW,转换效率达16.9%. 相似文献
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S.N. Atutov V. Biancalana R. Calabrese V. Guidi P. Lenisa B. Mai E. Mariotti L. Moi L. Tomassetti 《Hyperfine Interactions》2000,127(1-4):503-506
A frequency comb in the UV region with a bandwidth greater than 100 MHz is generated by successive frequency shifts of a single
mode laser by an acousto-optic modulator coupled to a passive ring cavity. The obtained spectrum is particularly suitable
for laser cooling when a large velocity capture range is required as in the case, for example, of ions confined in a storage
ring.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
9.
Zhou Wang Chunping Zhang Guanghua Fu Xiangjun Yan Hemu Wang Guangying Zhang 《Chinese Journal of Lasers》1992,1(3):229-234
Forces exerted on a small transparent dielectric sphere in a Gaussian beam is an-alyzed.The stable position of the sphere in the Gaussian beam was calculated.The effects ofthe sphere size,the beam radius etc.on the exerted forces,on the equilibrium positions aswell as on other parameters of the sphere are discussed. 相似文献
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We suggest a variant, which has already been implemented, of a selective intracavity laser spectrometer with intracavity nonlinear
optical conversion of the frequency range of generated multimode radiation. The apparatus provides a means for transition
into the UV spectral range (shorter than 300 nm) to carry out direct recording and quantative investigation of strong resonance
lines of atomic absorption, which earlier were beyond the reach of the intracavity method. We measured selective absorption
in spectral lines of a number of metals: FeI 296.690 nm, TiI 294.200 nm, and GaI 287.424 nm.
Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, 70 F. Skorina Ave., Minsk, 220072, Belarus;
e-mail: Ild@imaph.bas-net.by. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 6, pp. 875–879, November–December,
1999. 相似文献
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Alexander Hemming Jim Richards Alan Davidson Phil Davies David Lancaster 《Optics Communications》2010,283(20):4041-14954
An efficient hybrid mid-IR laser system comprising a thulium fibre laser, Ho:YAG solid state laser and a zinc germanium phosphide optical parametric oscillator is presented. A 790 nm diode pumped 1908 nm thulium fibre laser operating at 30 W pumps an RTP q-switched Ho:YAG laser emitting 17 W at 40 kHz and 2090 nm. The zinc germanium phosphide optical parametric oscillator efficiently converts this into the 3-5 μm region producing 10.1 W with 59% optical conversion efficiency and an M2 = 1.5. 相似文献
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A. I. Vodchits V. I. Dashkevich N. S. Kazak V. K. Pavlenko V. I. Pokryshkin I. P. Petrovich V. V. Rukhovets A. S. Kraskovskii V. A. Orlovich 《Journal of Applied Spectroscopy》2006,73(2):285-291
We have studied an optical parametric oscillator (OPO) with an unstable telescopic cavity, placed inside the cavity of an
actively Q-switched multimode Nd3+:KGW pump laser. We used a KTP crystal as the nonlinear medium for the OPO. We have compared the emission characteristics
of OPOs with unstable telescopic and planar cavities. We have established that compared with the planar cavity, the unstable
cavity reduces the OPO beam divergence and improves the spatial distribution of the radiation energy in the far wave zone.
Based on our investigations, we have designed a compact eye-safe (λ = 1.578 μm) laser source with natural cooling, emitting
(for electrical pumping energy 7.3 J) pulses with pulse energy 22 mJ and pulse duration 6 nsec. The FWHM beam divergence for
the source is no greater than 3.5 mrad.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 2, pp. 254–259, March–April, 2006. 相似文献
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We show that the temperature of plasma produced by exposure of copper-zinc alloy specimens to laser radiation changes little
(within the limits of random errors) with a change in the conditions of the laser effect and chemical composition of the specimens.
With use of electric discharges (a low-voltage spark), systematic changes in the temperature of the plasma are observed when
the chemical composition of copper-zinc alloys changes.
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. 3, pp. 319–321, May–June, 1998. 相似文献
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UV coherent radiation at 330.2 nm and IR stimulated radiations at 2.34μm,2.21μm and 1.64μm were generated via processes of unequal-frequency two-photon(3S-6S)resonantly enhanced excitation and equal frequency hybrid resonant excitation with particularexcited wavelength in Na_2-Na system.The competition of the two processes is obviously. 相似文献
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V. N. Belyi N. S. Kazak A. G. Mashchenko B. B. Sevruk 《Journal of Applied Spectroscopy》1999,66(2):187-195
The conditions for collinear phase matching in the parametric generation of light in arbitrary directions of a biaxial KTP
crystal pumped by an Nd:YAG laser were investigated with the use of invariant expressions for the refractive indices of isonormal
waves. The tuning curves, effective nonlinear coefficients, spectral and angular phase-matching widths were calculated.
B. I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, 68, F. Skorina Ave., Minsk, 220072. Translated
from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 2, pp. 177–184, March–April, 1999. 相似文献
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Yu. H. Avetisyan A. H. Makaryan V. R. Tadevosyan K. L. Vodopyanov 《Journal of Contemporary Physics (Armenian Academy of Sciences)》2009,44(4):161-167
Generation of terahertz (THz) radiation by nonlinear mixing of laser frequencies in GaAs crystal is considered for the case of free and guided propagation of THz waves. In the first case the strong diffraction of the THz radiation leads to the deviation from the known square-law growth of the generator power with increasing crystal length, In the second case the spatial divergence of the exciting laser beam results in the appearance of a maximum in the generated power dependence on the radius of the nonlinear waveguide. According to estimations, the optimal radius of the laser beam is 18 μm for the waveguide length of 6 mm and the maximal generated THz power is ~27 W at the laser beam power of 10 kW. 相似文献
18.
We have studied the ratio of the intensities of radiation scattered by a layer of blood in a cuvet and by the cuvet walls
for normal incidence or incidence at the Brewster angle for probing radiation from a He-Ne laser, linearly polarized in the
plane of incidence (plane of observation) or orthogonal to that plane. We have compared it with the intensity of the radiation
reflected by the surface of the cuvet wall, as estimated based on the geometric approximation. We have found the optimal conditions
for probing and observing scattering for the layer in a cuvet, where such conditions are characterized by a minimal effect
from the cuvet walls and the maximum ratio of useful signal to background.
Report given at the Fifth International Scientific and Technical Conference on Quantum Electronics, 22–25 November 2004, Minsk,
Belarus.
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Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 2, pp. 270–272, March–April, 2006. 相似文献
19.
The parametric optimization of the Ne--CuBr UV laser excited by
longitudinal pulsed discharge is analysed by using a self-consistent
kinetic model. Consistent characteristics of the optimization
process are obtained by comparing with the experimental results.
Simulation results show that neon ions come into being along with
considerable depletion of the ground-state copper atoms. And the
optimization of the discharge tube diameter is the tradeoff between
the specific output photon density and the total active volume. Both
the optimal neon gas pressure and the optimal reservoir temperature
result from the balance between the neon ion density and the
ground-state copper atom density to arrive at a maximum of their
product. 相似文献
20.
N Y Shaparev 《中国物理 B》2016,25(10):103203-103203
In this paper, we analyze the spectral behavior(optical thickness, shape and linewidth) of laser radiation absorption under the correlation heating of ions in an ultracold plasma. The Voigt formula is used to find the absorption coefficient.The spectral line width is shown to grow with time while the optical thickness reduces. Our modeling results are in good agreement with the experimental findings reported in the literature. 相似文献