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Exploring the vacuum ultraviolet photochemistry of astrochemically important triatomic molecules

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National Science Review 2023年第8期10卷 243-259页

作者： Yao Chang Michael N.R. Ashfold Kaijun Yuan Xueming Yang State key laboratory of molecular Reaction Dynamics and Dalian coherent light Source Dalian Institute of Chemical Physics Chinese Academy of Sciences School of Chemistry University of Bristol University of Chinese Academy of Sciences Hefei National laboratory Department of Chemistry College of Science Southern University of Science and Technology

The recently constructed vacuum ultraviolet(VUV) free electron laser(FEL) at the Dalian coherent light Source(DCLS) is yielding a wealth of new and exquisitely detailed information about the photofragmentation dynamics of many small gas-phase molecules. This review focuses particular attention on five triatomic molecules—H2O, H2S, CO2, OCS and CS2. Each shows excitation wavelength-dependent dissociation dynamics, yielding photofragments that populate a range of electronic and(in the case of diatomic fragments) vibrational and rotational quantum states, which can be characterized by different translational spectroscopy methods. The photodissociation of an isolated molecule from a well-defined initial quantum state provides a lens through which one can investigate how and why chemical reactions occur, and provides numerous opportunities for fruitful, synergistic collaborations with high-level ab initio quantum chemists. The chosen molecules, their photofragments and the subsequent chemical reaction networks to which they can contribute are all crucial in planetary atmospheres and in interstellar and circumstellar environments. The aims of this review are 3-fold: to highlight new photochemical insights enabled by the VUV-FEL at the DCLS, notably the recently recognized central atom elimination process that is shown to contribute in all of these triatomic molecules; to highlight some of the potential implications of this rich photochemistry to our understanding of interstellar chemistry and molecular evolution within the universe; and to highlight other and future research directions in areas related to chemical reaction dynamics and astrochemistry that will be enabled by increased access to VUV-FEL sources.

关键词： vacuum ultraviolet photochemistry photodissociation free electron laser interstellar chemistry chemistry of planetary atmospheres

UV and visible upconversion luminescence in Er^3＋：YAG under red laser excitation

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Chinese Physics B 2007年第6期16卷 1650-1654页

作者：杨海贵戴振文祖宁宁 Department of Physics Jilin University Key Laboratory of Coherent Light Atomic and Molecular Spectroscopy Ministry of Education Changchun 130023 China

This paper reports that the ultraviolet and visible upconversion luminescence from the ^4S3/2, ^2G9/2 and ^2P3/2 levels have been observed in Er^3＋：YAG following 647.2 nm excitation of the ^4F9/2 multiple. Upconversion luminescence intensity dependence on pump power was recorded. The measured decay profiles were theoretically fitted by kinetics theory and the basically good agreements were achieved. The results indicate that some energy transfer processes proposed to explain the observed upconversion phenomena are reasonable.

关键词： upconversion luminescence dynamics Er^3+:YAG

Analysis of sampled fiber Bragg gratings polarization-maintaining fiber

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Chinese Optics Letters 2008年第7期6卷 479-482页

作者：雷永庆韦珏徐晓峰李亚娟 key laboratory of coherent light Atomic and Molecular SpectroscopyCollege of PhysicsJilin UniversityChangchun 130023

A novel type of sampled fiber Bragg gratings （FBGs） written in polarization-maintaining fiber （PMF） is proposed. The reflection spectrum, time delay, and group velocity dispersion （GVD） of the gratings are analyzed. In addition, the reflection spectrum is optimized by apodization. The scheme of multi-wavelength output based on the gratings is proposed, which could be used as a multi-wavelength polarization filter in the density wavelength division multiplexed （DWDM） system.

关键词： Computer networks Electromagnetic waves Fiber optic sensors Fiber optics Fibers light polarization Multiplexing Optical filters Polarization Reflection

High index of refraction via quantum interference in a three-level system of Er^3＋-doped yttrium aluminium garnet crystal

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Chinese Physics B 2006年第8期15卷 1798-1805页

作者：何琼毅王铁军高锦岳 CCAST (World laboratory) Beijing 100080 China College of Physics Jilin University Changchun 130023 China key laboratory of coherent light Atomic and Molecular SpectroscopyEducational Ministry of China Changchun 130023 China

A simple three-level system is proposed to produce high index of refraction with zero absorption in an Er^3＋-doped yttrium aluminium garnet （YAG） crystal, which is achieved for a probe field between the excited state 4I13/2 and ground state 4I15/2 by adjusting a strong coherent driving field between the upper excited state 4I11/2 and 4I15/2. It is found that the changes of the frequency of the coherent driving field and the concentration of Er^3＋ ions in the YAG crystal can maximize the index of refraction accompanied by vanishing absorption. This result could be useful for the dispersion compensation in fibre communication, laser particle acceleration, high precision magnetometry and so on.

关键词： electromagnetically induced transparency high index of refraction with zero absorption Er^3+-doped yttrium aluminium garnet crystal

Raman investigation of hydration structure of iodide and iodate

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Chinese Physics B 2021年第4期30卷 226-230页

作者：刘喆赵洪亮郎鸿志王莹李占龙门志伟汪胜晗孙成林 key laboratory of Physics and Technology for Advanced Batteries(ministry of Education) College of PhysicsJilin UniversityChangchun 130012China coherent light and atomic and molecular spectroscopy laboratory College of PhysicsJilin UniversityChangchun 130012China College of Aviation Foundation Aviation University of Air ForceChangchun 130000China

In the troposphere,the destruction of ozone and the formation of new particles are closely related to the iodine content,which mainly comes from iodide(I^(-)) and iodate(IO_(3)^(-)) in the ***,understanding the interactions between I^(-),IO_(3)^(-)and water molecules plays a certain role in alleviating the destruction of the ozone *** spectroscopy is commonly used to obtain the information of the interaction between I^(-),IO_(3)^(-)and water molecules quickly and ***,the effect of I^(-)and IO_(3)^(-)on the change in Raman band characteristics of water is investigated to reflect the associated intermolecular interactions *** the addition of the two ions,the Raman band corresponding to OH stretching vibration moves towards the high wavenumber,indicating the formation of hydration *** narrowing of the Raman band from OH stretching vibration under weak hydrogen bond agrees well with the hydrogen bond variation,while the abnormal broadening of the Raman band from OH stretching vibration under strong hydrogen bond indicates the formation of H-down *** the increase of ions concentration,the frequency shift of the Raman band from OH stretching vibration under both weak and strong hydrogen bonds becomes more ***,the frequency shift of I^(-)is more obvious than that of IO_(3)^(-),which indicates that I^(-)is more likely to form the hydration structure with water than IO_(3)^(-).These results contribute to analyzing the different interactions between I^(-)-water and IO_(3)^(-)-water,then helping to prevent ozone depletion.

关键词： Raman spectroscopy hydrogen bond hydration structure

Group velocity dispersion effect on the collapse of femtosecond laser pulses in air: a revised form for Marburger's law

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Chinese Optics Letters 2015年第12期13卷 58-61页

作者：李苏宇金明星 Institute of atomic and molecular Physics Jilin University Jilin Provincial key laboratory of Applied atomic and molecular spectroscopy(Jilin University)

The influence of group velocity dispersion（GVD） on the self-focusing of femtosecond laser pulses is investigated by numerically solving the extended nonlinear Schr？dinger equation. By introducing the GVD length LGVDinto the semi-empirical, self-focusing formula proposed by Marburger, a revised one is proposed, which can not only well explain the influence of GVD on the collapse distance, but also is in good agreement with the numerical results, making the self-focusing formula applicable for more cases.

关键词： Air Dispersions Focusing Group velocity dispersion Laser pulses light velocity Nonlinear equations Ultrafast lasers

A tunable XUV monochromatic light source based on the time preserving grating selection of high-order harmonic generation

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Chinese Physics B 2017年第7期26卷 194-198页

作者：牛永梁红静刘燚刘方圆马日丁大军 Institute of atomic and molecular Physics Jilin University Jilin Provincial key laboratory of Applied atomic and molecular spectroscopy Jilin University

We accomplish a laboratory facility for producing a femtosecond XUV coherent monochromatic radiation with a broad tunable spectral range of 20 eV-75 eV. It is based on spectral selected single-order harmonics from intense laser driven high harmonic generation in gas phase. The time preserving for the selected harmonic radiation is achieved by a Czerny-Turner type monochromator designed with a conical diffraction grating mount for minimizing the time broadening caused by grating diffraction and keeping a relatively high diffraction efficiency. Our measurement shows that the photon flux of the 23-order harmonic（H23） centered at 35.7 eV is 1×10~9 photons/s approximately with a resolving power E/？E ≈ *** source provides an ultrashort tunable monochromatic XUV beam for ultrafast studies of electronic and structural dynamics in a large variety of matters.

关键词： high harmonic generation conical diffraction time preserving monochromator femtosecond extreme ultraviolet pulse

Field-free orientation of diatomic molecule via the linearly polarized resonant pulses

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Chinese Physics B 2015年第10期24卷 213-217页

作者：李苏宇郭福明王俊杨玉军金明星 Institute of atomic and molecular Physics Jilin University Jilin Provincial key laboratory of Applied atomic and molecular spectroscopy Jilin University

We propose a scheme to coherently control the field-free orientation of NO molecule whose rotational temperature is above 0 K. It is found that the maximum molecular orientation is affected by two factors： one is the sum of the population of M = 0 rotational states and the other is their distribution, however, their distribution plays a much more significant role in molecular orientation than the sum of their population. By adopting a series of linearly polarized pulses resonant with the rotational states, the distribution of M = 0 rotational states is well rearranged. Though the number of pulses used is small, a relatively high orientation degree can be obtained. This scheme provides a promising approach to the achievement of a good orientation effect.

关键词： orientation diatomic molecule linearly polarized pulses coherent control

Ultraviolet and visible upconversion dynamics in Er^3＋：YAlO3 under ^2H11/2 excitation

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Chinese Physics B 2006年第6期15卷 1273-1277页

作者：杨海贵戴振文孙志伟 Department of Physics Jilin University Key Lab of Coherent Light Atomic and Molecular Spectroscopy Ministry of Education Changchun 130023 China

The luminescence of Er^3＋：YAlO3 in ultraviolet visible and infrared ranges under the 518 nm excitation of the multiples ^2H11/2 have been investigated. Ultraviolet （275 nm and 318 nm）, violet （405 nm and 413 nm） and blue （474 nm） upconversion and infrared downconversion luminescence has been observed. By means of measuring the fluorescence decay curves and using the theory of rate equations, the luminescence kinetics was studied in detail and the processes of energy transfer upconversion （ETU） and excitation state absorption （ESA） were proposed to explain the upconversion phenomena.

关键词： ultraviolet upconversion dynamics Er^3+:YAlO3