共查询到20条相似文献,搜索用时 15 毫秒
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本文从实验上研究了不同缓冲气体(He,Ar,N2和Air)中激光Al等离子体的时间分辨发射光谱,研究了原子发射谱线的强度和Stark展宽随延时、缓冲气体性质和压力变化的规律.结果表明原子谱线的强度在3μs左右达到最大值,随着延时的增加,谱线的Stark展宽减小,而缓冲气体压力的增大导致谱线的Stark展宽增大,在实验测定的四种缓冲气体中,Ar气体中谱线的Stark展宽最大. 相似文献
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《Physics letters. A》1998,248(1):80-85
We report an experimental investigation of coherent population trapping in specially selected Zeeman levels of the sodium atom, performed under high buffer gas pressure in a polydimethylsiloxane coated cell at room temperature. The results show that coherent population trapping will not be completely destroyed when the buffer gas pressure reaches 1100 Torr for He and 1000, 800, and 500 Torr, for Ne, Ar and Kr, respectively. Buffer gases with heavier mass play a larger destructive role for the coherent population trapping. The line width of the dark resonance is reduced with buffer gas pressure. The behavior of the dark resonances on increasing buffer gas is discussed and possible applications are pointed out. 相似文献
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J. S. Bakos T. Kárpáti Zsuzsa Sörlei 《International Journal of Infrared and Millimeter Waves》1987,8(6):663-671
The gain line shape of wevelength 119 um of the methanol molecule is measured at different He buffer gas pressure. The amplitude of the gain decreases and the linewidth increases with the increase of the buffer gas pressure. The rate of the increase of the width is 3MHz/torr. 相似文献
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The effect of a light buffer gas on the anharmonic oscillation of ions trapped in a rf trap is studied. The rf resonance absorption signals showed a change of the signal height and the hysteresis with the sweep direction of the dc voltage or the probing frequency due to the anharmonicity of the pseudopotential well of a rf trap. It was found that the signals changed drastically or even disappeared depending on the pressure of buffer gas, although almost the same number of ions were trapped. These effects indicate that the sensitivity of detection of the trapped ions can be improved by appropriately choosing the pressure of the buffer gas and the sweep direction. The trapped ions could be detected until 76 h 20 min and the storage time of 1.3×105 s was determined when these parameters were optimized. 相似文献
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Xiao Huang Xun Zhang Xizhang Luo Jiayin Qin 《International Journal of Infrared and Millimeter Waves》2001,22(5):779-786
A miniature superradiant NH3 optically pumped far-infrared laser (OPFIRL) with buffer gas N2 was theoretically studied. Base on the mechanism model of buffer gas, synthetical relaxation time was calculated. By solving the semi-classic density matrix equations, spectra of NH3 superradiant OPFIRL with buffer gas N2 was calculated, also the operating gas pressure. It was found that by adding buffer gas, FIR power could be raised, and there existed an optimum ratio of gases mixture and an optimum operating gas pressure which was higher than that of pure NH3 operating. 相似文献
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Dependence of the ^85Rb coherent population trapping resonance characteristic on the pressure of N2 buffer gas 下载免费PDF全文
In order to exploit its potential applications, we experimentally study the dependence of ^85 Rb-based coherent population trapping (CPTi resonance on N2 buffer gas with 6 vapor cells filled with natural rubidium and N2. The experiments are carried out at different pressures and temperatures, and the results reveal that higher cell temperature makes the resonance more sensitive to N2 pressure. Thus, it is importmlt to choose a proper buffer gas pressure at a given cell temperature. This work provides valuable data for the application of 85Rb CPT resonance with a buffer gas of N2. 相似文献
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Effects of Buffer Gas on the Output of Optically Pumped NH3 Far-Infrared Cavity Laser 总被引:1,自引:0,他引:1
Hongjian Li Xizhang Luo Xiao Huang Ruman Qiu 《International Journal of Infrared and Millimeter Waves》2000,21(5):771-780
By solving the semi-classical density matrix equations and developing a buffer gas mechanism model, the effects of buffer gas on the output power of optically pumped NH3 far-infrared cavity laser were calculated and verified by experiment. Our results showed that: the output power of NH3 far-infrared laser could be increased when certain buffer gas was added into the laser medium, and there existed an optimum ratio of gases mixture and an optimum operating gas pressure which could make the output power of far-infrared laser reach maximum. 相似文献
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We report experimentally the transformation from the electromagnetically induced transparency (EIT) resonance to a dispersion-like signal and eventually to a nearly symmetric absorption resonance as coupling detuning increases in A-type three-level system in the cesium vapor cell with buffer gas at room temperature. The observed absorption resonance occupies some remarkable properties of the strong amplitude and the narrow linewidth in comparison with the case without buffer gas. The relation between linewidth of the enhanced absorption resonance and buffer gas pressure is studied. With pressure increasing, linewidth of the absorption resonance becomes narrow. The sub-natural linewidth is observed in Doppler-broadened cesium vapor cell in our experiment. The experimental results are in qualitative agreement with the numerical simulations. 相似文献
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Pressure Dependence of the Small-Signal Gain and Saturation Intensity of a Copper Bromide Laser 下载免费PDF全文
《中国物理快报》2017,(8)
A pair of copper bromide lasers in an oscillator-amplifier configuration is used to investigate the small signal gain and saturation intensity as amplifying parameters and output power of lasers, versus pressure of buffer gas. It is shown that the amplifying parameters and laser output power have a maximum value at optimum buffer gas pressure of 11 Torr. The challenge between microscopic parameters such as stimulated emission cross section, laser upper level lifetime, and population inversion, which determine the values of laser characteristics respective to the operational pressure of buffer gas, are investigated. Thus an optimum delay time of about 10 ns is determined, and a maximum output power equivalent to about 12 W is extracted. The amplifying parameters and measured output power of laser versus delay times show some local maxima and minima at the delay time interval of 6-43 ns. 相似文献
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以无缓冲气化学氧碘激光器(COIL)实验器件的数据计算得到的混合喷管出口参数平均值作为光腔入口条件,对6种不同构型的扩压器从光腔入口至扩压器出口的流场进行了数值模拟,得出了各流场参数分布;对不同构型扩压器的流场特点、总压恢复性能进行了分析;研究了扩压器出口背压对流场参数的影响。结果表明:对于主流无缓冲气的COIL,等截面扩压器具有较好的压力恢复性能;增大扩压器出口背压可以使扩压器的压力恢复性能提高,然而,较高的背压使激波串向光腔方向移动,从而使光腔流场受到干扰,影响光腔的光束质量。 相似文献
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研究了不同条件下脉冲放电CO2激光烧蚀平板锡靶产生的等离子体极紫外辐射特性, 设计并建立了一套掠入射极紫外平焦场光栅光谱仪, 结合X射线CCD探测了光源在6.5~16.8 nm波段的时间积分辐射光谱,得到了极紫外光谱随激光脉宽, 入射脉冲能量及背景气压的变化规律。实验结果发现:入射激光脉冲能量在30~600 mJ变化时,极紫外辐射光谱的强度随辐照激光脉冲能量的增加而增加, 但并不是线性关系, 具有饱和效应, 且产生极紫外辐射的脉冲能量阈值约为30 mJ,当激光脉冲能量为425 mJ时具有最高的转换效率,此时中心波长13.5 nm处2%带宽内的转换效率约为1.2%。激光脉冲半高全宽在50~120 ns范围内变化时, 极紫外辐射光谱的峰值位置均位于13.5 nm,光谱形状几乎没有什么变化, 但是脉宽从120 ns变到52 ns后,由于激光功率密度的提高,极紫外辐射强度也随之增强了约1.6倍。极紫外光谱的强度随背景气压的增大而迅速下降, 当腔内空气气压为200 Pa时, 极紫外辐射光子几乎被全部吸收,而当缓冲氦气气压为7×104 Pa时,仍能够探测到微弱的极紫外辐射信号,计算表明100 Pa的空气对13.5 nm极紫外光的吸收系数为3.0 m-1,而100 Pa的He气的吸收系数为0.96 m-1。 相似文献
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The influence of hydrocarbon compounds such as methane, ethane and ethylene on collision-induced amplified emission in sodium vapour has been investigated. The intensity dependence of the stimulated resonant emission and stimulated Raman effects on the buffer gas and sodium vapour pressures and the intensity of the excitation radiation has been obtained. The dependence of the stimulated resonant emission bandwidth on the buffer gas pressure has also been measured. It is shown that saturated hydrocarbon molecules can be used as an efficient buffer gas for the generation of stimulated emission in other alkali atoms such as rubidium and caesium. 相似文献
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A pair of gold-vapor laser (627.8 nm) in an oscillator-amplifier configuration was used to investigate the small signal gain, g0, and saturation intensity, Is, as amplifying parameters, versus pressure at various types of buffer gas. It was shown that the small signal gain decreases and saturation intensity increases linearly with increasing the pressure. Moreover, the values of these parameters are different using various gas mixtures in gain medium. Both parameters were estimated to be more at helium buffer gas atmosphere than that of neon or their mixed ones. 相似文献
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E. A. Vasil’ev E. M. Gushchin N. A. Mikhanchuk I. M. Obodovskii S. G. Pokachalov 《Russian Journal of Physical Chemistry B, Focus on Physics》2010,4(4):671-675
The rates of free thermal electron capture were measured depending on the buffer gas (CO2) pressure for 15 organic compounds in an ionization chamber with laser cathode photoionization. Procedures for preparing
the tested gas mixtures and experimental data processing are described. 相似文献
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Wang Yongjiang Shen Shengpen Xia Tiejun Wu Zhehua Zhu Jinmin 《Applied physics. B, Lasers and optics》1988,46(2):191-195
The atomic density, the buffer gas pressure, and the voltage dependence of the 510.6 nm laser line shape and its temporal evolution emitted from a Cu/CuBr vapor laser are measured. It is found that the monochromaticity of these laser lines can be improved greatly at a relative high buffer gas pressure. The temporal evolution of the line shape offers a stereoscopic view of a laser pulse. The sequence of appearance of the peaks of the line shape is governed by the intensity of the hyperfine component of the copper line. 相似文献
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Sheldon S.Q. Wu Thomas F. Soules Scott C. Mitchell Raymond J. Beach 《Optics Communications》2008,281(5):1222-1225
We report a demonstration of a 795-nm rubidium optical resonance transition laser using a buffer gas consisting of pure 3He. This follows our recent demonstration of a hydrocarbon-free 795-nm rubidium resonance laser which used naturally-occurring He as the buffer gas. Using He gas that is isotopically enriched with 3He yields enhanced mixing of the Rb fine-structure levels. This enables efficient lasing at reduced He buffer gas pressure, improved thermal management in high average power Rb lasers and enhanced power scaling potential of such systems. 相似文献
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Optimizations of gas composition and input energy were performed for gas mixtures containing a buffer gas and either Ar, Kr or Xe as the lasing gas. The total gas pressure was varied between 1 and 14 bar and the input energy from 0.03 to 0.7 J/cm3. The excitation source was a small coaxial electron beam with a pumping length of 20 cm and a pulse length of 30 ns (FWHM). From an active volume of 13.3 cm3 a maximum output energy of 12 mJ was obtained from a gas mixture containing 0.3% Xe in Ar at a total gas pressure of 10 bar. The intrinsic efficiency was 0.9%. 相似文献