SYSTEMATIC STUDY OF POLARIZATION OF TWO-PHOTON ABSORPTION IN SYMMETRY ASSIGNMENTS

In this paper, we have systematically analyzed the degenerate and nondegenerate two-photon polarization ratios of various point groups. We present the maximum of symmetry assignments of two-photon transition with the combination of degenerate and nondegenerate two-photon absorption. These results provide the theoretical basis for the experimental assignments.     

Cu2O和Ge的基本反射光谱——两种不同性质的反射带结构

本文在室温下测量了Cu₂O和Ge的基本反射光谱(0.22—1.00μ);研究了区分激子反射带结构和带际跃迁反射带结构的实验方法。光学抛光处理晶体表面对反射光谱中激子结构的影响极大,但对带际跃迁结构的影响不大。确定了Cu₂O紫外反射带的带际跃迁性质。讨论了Cu₂O和Ge的基本反射光谱和能带结构的联系。特别注意了Ge的反射光谱中的一些弱结构和能带结构的联系。工作中也涉及了晶格的有序度和能带结构的联系和吸收气氛影响短波反射带“下塌”的现象。     

气相吡啶分子S1态的(2+3)偏振共振多光子电离谱研究

利用气相吡啶分子分别在圆偏振光激发和线偏振光激发下的（２＋３）偏振共振多光子电离（ＰＲＭＰＩ）谱,对其第一激发态（Ｓ１）上的振转结构进行了研究。在谱中观察到了呈双峰结构的电子振转跃迁谱带。分析表明,所有振动谱带均为Ｓ１态上Ｖ６ａ、Ｖ１０ａ、Ｖ１２、Ｖ１６ｂ和Ｖ１７ａ以及基态上Ｖ９ａ的混合频率谱带。旨认吡啶Ｖ１７ａ的Ｓ１态频率为６７０ｃｍ＾－１,并认为在Ｓ１态上Ｖ７ａ频率降低的原因与Ｖ１０ａ类似。     

InCl分子C1Π1态光谱研究

采用激光诱导荧光技术对InCl分子C1Π1→X1Σ+荧光光谱进行了分析和归属, 在发射谱中探测到ν′=1向下的跃迁, 证明C态预离解只能发生在ν′=1之上。 并对C1Π1→X1Σ+的荧光衰变曲线进行了观测, 得到InCl分子C1Π1(ν′=1)态的无碰撞辐射寿命τ0≈11 ns及电子跃迁矩|Re|2≈5.95D2。     

CW Nd:YAG THERMO-STABLE RESONATORS OPERATING IN POWER-STEADY STATES

There are two dynamical stable zones in the operation of solid laser containing a thermal lens. In this paper, we point out that in the two stable zones two kinds of dynamical stable states can exist in a laser resonator: mode-steady thermo-stable state and power-steady thermo-stable state. They are different from each other in general. The operating conditions for power-steady thermo-stable state are presented. A cw Nd: YAG thermo-stable resonator operating in power-steady states has been designed, and 40 W TEM₀₀ output power in 1.06μm is obtained experimentally.     

EFFECT OF THE LASER TRANSVERSE SPATIAL DISTRIBUTION ON MULTIPHOTON IONIZATION PROCESSES

In this paper, the dependence of the photoionization cross section σ₂, total ion number N_i and the FWHM of photoionization spectral line in resonant multiphoton ionization processes(RMPI) upon the parameter C of the laser transverse spatial distribution has been studied. Considering the effects of spatial coordinate on the resonant multiphoton absorption cross section σ₁, the limited dimension of the laser-molecular interaction volume and threshold of laser intensity for RMPI, we deduce the expression of σ₂ vs the parameter C. We calculated the value of σ₂ for (2+2)PI of benzene by numerical method, and com-pared the result with that obtained by Bruzzeste et al. In additon, we also present the total ion number of photoionization and the FWHM of photoionization spectral line as a function of the parameter C.     

STUDY OF THE POLARIZATION SPECTROSCOPY OF 3p RYDBERG STATES OF m-DIMETHYLBENZENE

A polarization-selected three-photon resonant multiphoton ionization investigation of the 3p Rydberg region of the spectra of m-dimethylbenzene has been conducted. Several vibronic states have been discovered and also assigned for the first time.     

STUDY OF THREE-PHOTON RESONANCE MULTIPHOTON IONIZATION SPECTROSCOPY OF 3p RYDBERG STATES OF m-DIMETHYLBENZENE WITHIN DYE Rh560

In this paper, we studied experimentally the three-photon resonance four-photon ionization spectroscopy of m-dimethylbenzene within dye Rh560. We found several new 3p Rydberg vibronie states and measured their polarization characters. With the help of the measured polarization quantities, we gave the assignment results of these vibronic states: 9b₀¹, A₁; 13₀¹, A₁; 19a₀¹, A₁; 8a₀¹, A₁.     

Cu_2O和Ge的基本反射光谱——两种不同性质的反射带结构

本文在室温下测量了Cu_2O和Ge的基本反射光谱(0.22—1.00μ);研究了区分激子反射带结构和带际跃迁反射带结构的实验方法。光学抛光处理晶体表面对反射光谱中激子结构的影响极大,但对带际跃迁结构的影响不大。确定了Cu_2O紫外反射带的带际跃迁性质。讨论了Cu_2O和Ge的基本反射光谱和能带结构的联系。特别注意了Ge的反射光谱中的一些弱结构和能带结构的联系。工作中也涉及了晶格的有序度和能带结构的联系和吸收气氛影响短波反射带“下塌”的现象。