Efficient rotational Raman conversion of XeCl laser radiation in H2

2 is investigated with a XeCl laser. It is shown that energy conversion to rotational Stokes radiation can be efficiently obtained by properly choosing the focusing geometry of pump radiation and the pressure of the Raman medium even at moderate pulse energies. Energy conversion to the first rotational Stokes at 313.8 nm with efficiencies as high as 38% is obtained with a circularly polarised XeCl pump beam of 10-mJ energy focused in 30 bar of H₂. The spectral and optical characteristics of the pump and the rotational Stokes radiation are analysed. Received: 29 May 1996/Revised version: 7 March 1997     

XeCl准分子激光在铅蒸气中的高效率受激电子喇曼散射

本文报道了采用非稳腔XeCl准分子激光泵浦铅蒸气获得52%喇曼能量转换效率.比较了稳腔与非稳腔XeCI激光泵浦下的喇曼转换特性.     

The self-injected XeCl excimer laser

We present experimental and modelling results of the first self-injected excimer laser. The intracavity losses of a XeCl oscillator are properly modulated by a Pockels cell allowing generation, amplification and extraction of short laser pulses with selectable duration in the range of 1–12 ns, tailored temporal profile and peak power increment up to a factor of three. Longer output laser pulses, up to 100 ns, can be obtained by slicing the intracavity laser radiation without peak power increment. Laser output peak powers in excess of 2 MW have been obtained, with remarkable reproducibility characteristics.ENEA fellow     

准分子激光束的喇曼整形

受激喇曼散射可以将紫外准分子激光辐射频移到特定的近紫外和可见光波长.采用喇曼整形技术还可以获得衍射极限发散角的斯托克斯输出.本文研究了注入光束质量对喇曼整形的影响,并求得不同氢压力下的喇曼增益系数和饱和参量.     

准分子激光束的喇曼组束

受激喇曼散射可以将紫外准分子激光辐射频移到特定的近紫外或可见光波长,采用喇曼整形技术可以改善斯托克斯光的光束质量,本文报道喇曼组束提高喇曼整形效率的实验结果.     

Efficiency of raman conversion of XeCl laser radiation in metal vapors

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 55, No. 1, pp. 80–83, July, 1991.     

电子束泵浦XeCl准分子激光器及应用

为了获得高能紫外激光输出,开展了电子束泵浦XeCl准分子激光技术研究。详细介绍了四向电子束泵浦准分子激光装置的工作原理和结构特征,简述Marx发生器的放电电压、放电电流,激光气室中的沉积能量,激光脉冲能量、脉宽等参数的测量方法;研究了电子束泵浦XeCl准分子激光输出特性,得到了激光脉冲能量随激光气室内混合气体气压变化的规律,当激光器的充电电压为81kV时,获得了能量100J、脉宽200ns的XeCl准分子激光输出,其本征效率约为3.2%。并且开展了XeCl准分子激光辐照涂层材料力学特性研究,采用微型红外通光冲量探头测量不同条件下激光辐照涂层材料的冲量耦合系数,在常压空气环境中的冲量耦合系数约为8.32×10-5 N·W-1。     

电子束泵浦XeCl准分子激光器及应用

为了获得高能紫外激光输出,开展了电子束泵浦XeCl准分子激光技术研究。详细介绍了四向电子束泵浦准分子激光装置的工作原理和结构特征,简述Marx发生器的放电电压、放电电流,激光气室中的沉积能量,激光脉冲能量、脉宽等参数的测量方法;研究了电子束泵浦XeCl准分子激光输出特性,得到了激光脉冲能量随激光气室内混合气体气压变化的规律,当激光器的充电电压为81 kV时,获得了能量100 J、脉宽200 ns的XeCl准分子激光输出,其本征效率约为3.2%。并且开展了XeCl准分子激光辐照涂层材料力学特性研究,采用微型红外通光冲量探头测量不同条件下激光辐照涂层材料的冲量耦合系数,在常压空气环境中的冲量耦合系数约为8.3210-5 NW-1。     

Ultrafine structure spectrum of XeCl excimer laser

The computation of the rotational lines based on the coupling of vibration and rotation of XeCl excimer was introduced to explain the ultrafine structure spectrum of XeCl excimer laser. The calculated results are in good agreement with that of the experiment.     

XeCl准分子激光的超精细光谱结构

本文通过振动-旋转耦合的旋转谱线计算,解释了XeCl准分子激光的超精细光谱结构.计算结果与实验很好地符合.     

高重复频率XeCl准分子激光器

本文报道一台高重复频率XeC准分子激光器的结构及其特性。采用接地栅金属陶瓷闸流管开关和气体横向流动系统及自动紫外火花预电离的放电结构。该激光器最高单脉冲能量为200mJ,最高重复脉冲频率为107Hz,最大平均功率18W。     

Raman spectroscopy of SWNTs produced by a XeCl excimer laser ablation at high temperatures

Synthesis of single-wall carbon nanotubes (SWNTs) was carried out by an ablation method using a XeCl excimer laser. It was irradiated onto a graphite target containing Co and Ni at the temperatures of 1073, 1173, 1273, 1373, 1473, 1523 and 1623 K under the atmosphere (0.1 MPa) of Ar gas with the flow rate of 12 ml/min. The measurement by a scanning/transmission electron microscope and Raman spectroscopy found the formation of SWNTs with the diameter of about 1.3 nm and the length of about 2 μm in ablated carbonaceous soot. The ratio of peak intensity of 1590 cm⁻¹ (G band) to that of 1335 cm⁻¹ (D band) in the high frequency Raman spectra increased with increasing the ambient temperature. The radial breathing mode (RBM) in the low frequency Raman spectra shows that the mean diameter of SWNTs increased with increasing the ambient temperature.     

XeCl准分子激光能量提取研究

在高功率准分子激光系统建设中,希望能获得较短的脉冲宽度和尽量多的激光能量。实验研究了不同注入水平下,脉冲时间间隔对脉冲链放大波形和放大器提取效率的影响;基于四能级速率方程和准分子反应动力学建立了准分子激光放大模型,计算了多种注入方式下种子光的放大过程,对关键参数给出了量化描述,得到与实验相符的计算结果。研究结果显示:脉冲序列间隔为9.3 ns时,可获得约95%的连续注入情形下放大能量;对该准分子激光系统来讲,9.3 ns是比较合适的脉冲间隔。     

XeCl准分子激光能量提取研究

在高功率准分子激光系统建设中,希望能获得较短的脉冲宽度和尽量多的激光能量。实验研究了不同注入水平下,脉冲时间间隔对脉冲链放大波形和放大器提取效率的影响;基于四能级速率方程和准分子反应动力学建立了准分子激光放大模型,计算了多种注入方式下种子光的放大过程,对关键参数给出了量化描述,得到与实验相符的计算结果。研究结果显示:脉冲序列间隔为9.3ns时,可获得约95%的连续注入情形下放大能量;对该准分子激光系统来讲,9.3ns是比较合适的脉冲间隔。     

XeCl laser generated infra-red SRS in barium vapour

Radiation at 2.36 μm is produced by stimulated electronic Raman scattering in barium vapour. The pump radiation is provided by a XeCl excimer laser. Photon conversion efficiencies of up to 1% are observed. The variations of the infra-red Stokes output with barium number density and with pump intensity are described.     

Efficient discharge pumping XeCl laser

Pulsed oscillation from XeCl at λ = 3080 Å has been obtained by exciting a mixture of He:Xe:BCl₃ at pressures of 1 to 7 atm with a transverse discharge. The laser efficiency relative to the discharge absorbed energy exceeds 1%. The role of dissociation recombination in the processes of excitation of XeCl¹ is discussed.     

Stimulated Raman scattering of copper vapour laser radiation in optical fibres

Wideband frequency conversion of copper vapour laser radiation has been achieved by stimulated Raman scattering in multimode silica fibres. Up to nine Stokes' orders have been generated in the 511 to 649 nm spectral region with a conversion efficiency greater than 90% of the fibre output. Four-wave mixing processes involving laser and Stokes' lines have also been observed.     

Modeling of filament discharge development in a XeCl excimer laser

Dynamics of a filament discharge in a discharge-excited XeCl excimer laser medium has been simulated for a sequence of discharge pulses (shots). In the present model a filament discharge is triggered at a microprotrusion on a cathode surface. After the first discharge initiation, a hot spot is created near the cathode, then filament develops toward the anode in the second shot. Images of the filament discharge development and its properties in a XeCl excimer laser are presented     

XeCl准分子激光诱导的氮分子多光子电离

本文采用分子束和改装过的质谱装置,进行了氯化氙准分子激光诱导的氨分子紫外光电离的研究。我们不仅在(m/e)=16,17处分别观察到NH_2~+和NH_3~+离子峰,而且还在(m/e)=18处观察到NH_4~+离子峰。为搞清各种离子特别是NH_4~+离子的产生机理,测量了各种离子产率与样品压强和激光功率的依赖关系。     

XeCl excimer laser using chlorinated hydrocarbons as Cl donors

XeCl excimer laser emission has been observed in a fast transverse discharge system using vapors of several chloro-carbon and fluoro-chloro-carbon compounds. Laser characteristic are largely independent of the different molecules used. Efficiencies up to 0.9% have been obtained. The output energy decayed to half the maximum value in 15 000 shots for each fill. The evolution of laser emission with number of shots seems to be due to the discharge condition in the first stage. Complete quenching after prolonged running is due to some absorbing product formed by a reaction induced by the discharge. This new class of Cl donors appears to be very convenient because corrosive products are completely avoided and the gas handling system is substantially simplified.