~(15)N~(16)O(X~2∏)高分辨光谱的核超精细结构和∧-双分裂分析

从分子核超精细结构和∏-双分裂的理论出发, 导出了核超精细结构和∧-型双分裂谱线跃迁的简便计算公式. 通过这些公式对观测到的NO(X2∏)高分辨光谱进行分析计算, 快速准确地获得了15N16O分子的部分核超精细结构和∏-双分裂参数. 这一方法可为新分子谱线的标识和指认提供有效途径及准确参数依据.     

SPECTRAL SIMULATION TECHNIQUE AND ITS APPLICATION TO HIGH-RESOLUTION LMR SPECTRA OF NITRIC OXIDE

LMR(Laser Magnetic Resonance)光谱技术采用磁场扫描及磁场调制获得顺磁分子吸收谱线，其谱线具有Voigt线型及各不相同的磁场线宽.本文考虑线型理论模型和实验条件，提出了一种实现LMR谱精密仿真的方法，并设计了相应仿真计算程序.对     

Non-linear spectral splitting of Rydberg sodium in external fields

We have studied highly excited sodium in various electric fields,parallel electric and magnetic fields,with oneσandπphoton irradiation,and even in a magnetic field with a complex laser polarization configuration.Theσspectra shows a simple linear Stark effect with the applied electric field,while theπspectra exhibits a strong non-linear dependence on the electric field.Theπtransitions in parallel fields show a similar behavior to that in a pure electric field but the spectra get more smooth due to the magnetic field.The diamagnetic spectrum with laser polarization angles between 0 andπ/2 proves that it can be reproduced by simple linear combination ofπandσcomponents,indicating there is no interference between theπandσchannels.A full quantum calculation considering the quantum defects accounts for all the observations.The quantum defects,especially for the channel np,play an important role in the spectral profile.     

15N16O的激光磁共振谱与同位素分子15N17O和15N18O的光谱分析

采用内腔式饱和吸收技术获得Lamb凹陷,使CO激光磁共振谱仪的灵敏度及分辨率大大提高.利用该技术对自然丰度下¹⁵N¹⁶O的X²Π(υ=1)←X²Π(υ=0)塞曼跃迁进行测量,实现了包括Λ双分裂在内的各种精细结构的谱分辨.结合已发表的¹⁵NO同位素分子光谱实验数据进行分析计算,拟合得到迄今最完备、最精确的各相关同位素分子¹⁵N^mO(m=16—18)的结构参 关键词：     

GLOBAL ANALYSIS OF SPECTRA OF THE PO2 RADICAL IN THE GAS PHASE

A global analysis of all available and identified spectra of the PO₂ radical has been performed. In this analysis, the infrared spectra of the ν₃ band, the microwave and far infrared laser magnetic resonance transitions in the ground state are fitted simultaneously to the effective Hamiltonian for asymmetric top molecules. Since the analysis absorbs reliable experimental data extensively, it bears the most precise and most complete set of molecular constants for PO₂. These molecular constants can be used to reproduce the spectra of PO₂ accurately. Attention is also paid to the similarity and difference between PO₂ and NO₂.     

15N16O(X2P)高分辨光谱的核超精细结构和L-双分裂分析

从分子核超精细结构和L-双分裂的理论出发, 导出了核超精细结构和L-型双分裂谱线跃迁的简便计算公式. 通过这些公式对观测到的NO(X2P)高分辨光谱进行分析计算, 快速准确地获得了15N16O分子的部分核超精细结构和L-双分裂参数. 这一方法可为新分子谱线的标识和指认提供有效途径及准确参数依据.     

高分辨光谱的计算机自动读谱及辅助分析

本文以谱线中心位置在整个谱型中所独有的特性和噪声阈值为依据,提出了一种计算机自动获取谱线中心频率及其相对强度的简便算法,并设计了相应的计算机程序。将该方法和程序应用到具有代表性的由十多条CHF3谱线部分重迭组成的可调远红外实验谱图的预分析,结果表明所获取的谱线中心频率和相对强度与人工获取这些参数初值后经拟合得到的准确结果非常一致,验证了该方法和程序的准确性和有效性,表明其有着广泛的应用前景,可作为处理日益骤增的光谱信息的强有力工具。     

Transient electromagnetically induced transparency spectroscopy of 87Rb atoms in buffer gas

We study the transient response dynamics of ⁸⁷Rb atomic vapor buffered in 8 torr Ne gas through an electromagnetically induced transparency configured in $\varLambda$-scheme. Experimentally, the temporal transmission spectra versus probe detuning by switching on and off the coupling one show complex structures. The transmitted probe light intensity drops to a minimum value when the coupling light turns off, showing a strong absorption. Even at the moment of turning on the coupling light at a subsequent delayed time, the atomic medium shows a fast transient response. To account for the transient switching feature, in the time-dependent optical Bloch equation, we must take the transverse relaxation dephasing process of atomic vapor into account, as well as the fluorescence relaxation along with the optical absorption. This work supplies a technique to quantify the transverse relaxation time scale and to sensitively monitor its variation along the environment by observing the transient dynamics of coherent medium, which is helpful in characterizing the coherent feature of the atomic medium.     

A Time-Dependent Approach to High-Resolution Photoabsorption Spectrum of Rydberg Atoms in Magnetic Fields

A robust time-dependent approach to the high-resolution photoabsorption spectrum of Rydberg atoms in magnetic fields is presented. Traditionally we have to numerically diagonalize a huge matrix to solve the eigen-problem and then to obtain the spectral information. This matrix operation requires high-speed computers with large memories. Alternatively we present a unitary but very easily parallelized time-evolution method in an inexpensive way, which is very accurate and stable even in long-time scaie evolution. With this method, we perform the spectral caiculation of hydrogen atom in magnetic field, which agrees well with the experimentai observation. It can be extended to study the dynamics of Rydberg atoms in more complicated cases such as in combined electric and magnetic fields.     

Theoretical simulation of ~(87)Rb absorption spectrum in a thermal cell

In this paper,we present a theoretical simulation of ~(87)Rb absorption spectrum in a thermal cm-cell which is adaptive to the experimental observation.In experiment,the coupling and probe beams are configured to copropagate but perpendicular polarized,making up to five velocity selective optical pumping(VSOP) absorption dips able to be identified.A A-type electromagnetically induced transparency(EIT) is also observed for each group of velocity-selected atoms.The spectrum by only sweeping the probe beam can be decomposed into a combination of Doppier-broadened background and three VSOP dips for each group of velocity-selected atoms,accompanied by an EIT peak.This proposed theoretical model can be used to simulate the spectrum adaptive to the experimental observation by the non-linear least-square fit method.The fit for the high quality of experimental observation can determine valuable transition parameters such as decaying rates and coupling beam power accurately.