1
|
Sheng ZY, Yan Y, Cui PF, Yu J, Chai S, Cong SL. Effect of molecular orientation on predissociation of NaI molecules. Chem Phys 2022. [DOI: 10.1016/j.chemphys.2022.111690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
2
|
Zhou M, Guo MQ, Yu J, Chai S, Cong SL. The influence of molecular alignment and orientation in the ground state and excited state on the resonance-enhanced multi-photon ionization dynamics. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 262:120154. [PMID: 34271240 DOI: 10.1016/j.saa.2021.120154] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/25/2021] [Accepted: 07/02/2021] [Indexed: 06/13/2023]
Abstract
We explore the influence of molecular alignment and orientation in the ground and excited states on the ionization probability, photoelectron angular distribution (PAD), energy-resolved photoelectron energy spectrum (PES) and two-dimensional momentum spectrum in the resonance-enhanced multiphoton ionization (REMPI) process. The calculated results for the LiH molecule show that molecular pre-alignment and -orientation have different effects on molecular photoionization. The ionization probability and energy-resolved photoelectron spectrum are associated with molecular pre-alignment. The angular distribution of photoelectrons and angular distribution of the momentum spectra are closely dependent on molecular pre-orientation. The ionization probability is also related to the center time and overlap area of the pump and probe pulses.
Collapse
Affiliation(s)
- Min Zhou
- School of Physics, Dalian University of Technology, Dalian 116024, China
| | - Mei-Qi Guo
- School of Physics, Dalian University of Technology, Dalian 116024, China
| | - Jie Yu
- School of Physics, Dalian University of Technology, Dalian 116024, China.
| | - Shuo Chai
- School of Physics, Dalian University of Technology, Dalian 116024, China
| | - Shu-Lin Cong
- School of Physics, Dalian University of Technology, Dalian 116024, China
| |
Collapse
|
3
|
Zhou ML, Yu J, Wang GR, Cong SL. The photoionization dynamics based on molecular pre-orientation. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2019; 213:48-56. [PMID: 30685559 DOI: 10.1016/j.saa.2019.01.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Revised: 12/31/2018] [Accepted: 01/14/2019] [Indexed: 06/09/2023]
Abstract
We study theoretically the photoionization dynamics of pre-oriented NaK molecule. Firstly, a THz laser pulse is utilized to orient the ground state molecule. And then the pump and probe laser pulses are used to excite and ionize the molecule, respectively. We study the influence of molecular orientation duration and degree on the ionization probability, angle-resolved photoelectron spectrum and photoelectron angular distribution (PAD). It is shown that we could obtain more stable ionization signal and PAD when the molecules are ionized in molecular orientation duration. We could increase the ionization probability and obtain more concentrated ionization signal and photoelectron distribution by increasing the orientation degree in the ground state. Moreover, we discuss the splitting pattern in the angle-resolved photoelectron spectrum.
Collapse
Affiliation(s)
- Meng-Lin Zhou
- School of Physics, Dalian University of Technology, Dalian 116024, China
| | - Jie Yu
- School of Physics, Dalian University of Technology, Dalian 116024, China.
| | - Gao-Ren Wang
- School of Physics, Dalian University of Technology, Dalian 116024, China
| | - Shu-Lin Cong
- School of Physics, Dalian University of Technology, Dalian 116024, China
| |
Collapse
|
4
|
Zhang XM, Li JL, Yu J, Cong SL. The influence of molecular pre-orientation on the resonance-enhanced multi-photon ionization dynamics. Chem Phys 2017. [DOI: 10.1016/j.chemphys.2017.01.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
5
|
Wang R, Qiu MH, Xiu JL. Rovibrational State-Selectivity in Photoassociation through Multi-photon Transitions. CHINESE J CHEM PHYS 2014. [DOI: 10.1063/1674-0068/27/05/497-502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
|
6
|
Zhao ZY, Han YC, Yu J, Cong SL. The influence of field-free orientation on the predissociation dynamics of the NaI molecule. J Chem Phys 2014; 140:044316. [DOI: 10.1063/1.4863176] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
7
|
García-Vela A. Selective coherent control of the lifetime of a resonance state with laser pulses. J Chem Phys 2013; 139:134306. [PMID: 24116567 DOI: 10.1063/1.4823983] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
It is shown that new possibilities for control of the lifetime of a system in a resonance state emerge when the density of resonances overlapping and interfering with the target resonance increases. When using a control scheme combining two pump laser pulses, it is found that increasing the density of resonance states overlapping with the target one increases the selectivity of the scheme applied, and leads to achieve a remarkably higher degree of control. Lifetime enhancements by factors up to 20 are obtained when this selectivity is applied. The underlying reasons for such strong enhancements are analyzed and explained in the light of the equations of the model applied. Application of this strategy to control and enhance the lifetime of a system in excited states is envisioned.
Collapse
Affiliation(s)
- A García-Vela
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 123, 28006 Madrid, Spain
| |
Collapse
|
8
|
Zhao ZY, Han YC, Huang Y, Cong SL. Field-free orientation by a single-cycle THz pulse: The NaI and IBr molecules. J Chem Phys 2013; 139:044305. [DOI: 10.1063/1.4816121] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Ze-Yu Zhao
- School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024, China
| | | | | | | |
Collapse
|
9
|
Arbelo-González W, Bonnet L, García-Vela A. New insights into the semiclassical Wigner treatment of photodissociation dynamics. Phys Chem Chem Phys 2013; 15:9994-10011. [PMID: 23712618 DOI: 10.1039/c3cp50524c] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The semiclassical Wigner treatment of Brown and Heller [J. Chem. Phys. 1981, 75, 186] is applied to direct triatomic (or triatomic-like polyatomic) photodissociations with the aim of accurately predicting final state distributions at relatively low computational cost, and having available a powerful interpretative tool. For the first time, the treatment takes rotational motions into account. The proposed formulation closely parallels the quantum description as far as possible. An approximate version is proposed, which is still accurate while numerically much more efficient. In addition to being weighted by usual vibrational Wigner distributions, final phase space states appear to be weighted by new rotational Wigner distributions. These densities have remarkable structures clearly showing that classical trajectories most contributing to rotational state j are those reaching the products with a rotational angular momentum close to [j(j + 1)](1/2) (in ℏ units). The previous methods involve running trajectories from the reagent molecule onto the products. The alternative backward approach [L. Bonnet, J. Chem. Phys., 2010, 133, 174108], in which trajectories are run in the reverse direction, is shown to strongly improve the numerical efficiency of the most rigorous method in addition to being state-selective, and thus, ideally suited to the description of state-correlated distributions measured in velocity imaging experiments. The results obtained by means of the previous methods are compared with rigorous quantum results in the case of Guo's triatomic-like model of methyl iodide photodissociation [J. Chem. Phys., 1992, 96, 6629] and close agreement is found. In comparison, the standard method of Goursaud et al. [J. Chem. Phys., 1976, 65, 5453] is only semi-quantitative.
Collapse
|
10
|
|
11
|
YU JIE, SHU CHUANCUN, HU WENHUI, CONG SHULIN. ABOVE THRESHOLD IONIZATION OF POLAR NaK MOLECULES DRIVEN BY FEW-CYCLE LASER PULSE. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2011. [DOI: 10.1142/s0219633610006018] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We investigate theoretically the above-threshold ionization (ATI) of the polar NaK molecule exposed in few-cycle laser field by numerically solving the time-dependent Schrödinger equation including the vibrational and rotational degrees of freedom. The left and right ATI spectra are calculated by integrating the ionization continuum wave function over the left and the right half spheres along the laser polarization. We find that the left and right ATI spectra are asymmetric, and this asymmetry depends strongly on the molecular orientation and the carrier-envelope phase (CEP) of the laser pulse. Moreover, we also perform the calculation for different initially rotational states to study the effect of rotational temperature on the ATI dynamics.
Collapse
Affiliation(s)
- JIE YU
- School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian, 116024, P. R. China
| | - CHUAN-CUN SHU
- School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian, 116024, P. R. China
| | - WEN-HUI HU
- School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian, 116024, P. R. China
| | - SHU-LIN CONG
- School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian, 116024, P. R. China
| |
Collapse
|
12
|
YUAN KAIJUN, LIU ZHENGTANG, YU JIE, CHEN MAODU, CONG SHULIN. THEORETICAL STUDY OF ABOVE THRESHOLD DISSOCIATION OF HD+ IN FEMTOSECOND LASER FIELDS. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2011. [DOI: 10.1142/s0219633609005416] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The above threshold dissociation (ATD) of the HD+ molecular ion in a linearly polarized femtosecond laser field is theoretically studied using three-dimensional time-dependent quantum wave packet method. Based on the Born–Oppenheimer approximation (BOA), calculations are performed on two electronic states, the ground state 1sσ and the excited state 2pσ. The energy-dependent distributions of the dissociated fragments, resulting from the ATD, are calculated by using an asymptotic-flow expression in the momentum space. The numerical results demonstrate that, in the laser field of wavelength λ = 800 nm and full-width at half-maximum (FWHM) τ = 30 fs , only two-photon dissociation is observable at a weaker pulse peak intensity, 5.0 × 1012 W cm -2, while at an intense intensity, 1.5 × 1015 W cm -2, the dissociated fragments resulting from four-photon absorption dominates over the photodissociation process. These results are consistent with the experimental observation of Orr et al. [Orr PA et al., Phys Rev Lett98:163001, 2007]. The ac Stark-shift caused by intense laser field will change the kinetic energies of the fragments. The ATD phenomena are quantitatively interpreted in terms of the concept of light-induced potential. The molecular rotation and alignment have some effects on the kinetic energy spectrum of the dissociated fragments. The molecular rotation reduces the ac Stark-shift and broadens the peaks of kinetic energy spectra of the dissociated fragments. However, the intense laser field can effectively align the molecule and is helpful to increase the ATD probability. The ATD spectrum is related to the initial quantum numbers J0 and M0 of the molecule. The ATD spectrum of HD+ is calculated at a limited thermal temperature.
Collapse
Affiliation(s)
- KAI-JUN YUAN
- Department of Physics, Dalian University of Technology, Dalian 116024, China
| | - ZHENG-TANG LIU
- Department of Physics, Dalian University of Technology, Dalian 116024, China
| | - JIE YU
- Department of Physics, Dalian University of Technology, Dalian 116024, China
| | - MAO-DU CHEN
- Department of Physics, Dalian University of Technology, Dalian 116024, China
| | - SHU-LIN CONG
- Department of Physics, Dalian University of Technology, Dalian 116024, China
| |
Collapse
|
13
|
Korolkov MV, Weitzel KM. Femtosecond interferometry of molecular dynamics – the role of relative and absolute phase of two individual laser pulses. Z PHYS CHEM 2011. [DOI: 10.1524/zpch.2011.0154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
Dynamical implications of the dissociation of a molecular ion under the influence of interferometrically generated light fields have been investigated by numerical solution of time dependent Schrödinger equations. As an example the dissociation of DCl+ ions by means of two interfering 7 fs laser pulses at 800 nm has been chosen. We demonstrate that product branching ratios D+:Cl+ can be manipulated from 10:1 to 1:10 not only by adjusting the appropriate delay time in the time-shifted two-pulse approach, but also by choosing the proper carrier envelope phase (CEP) of the two partial light fields. The effects of the phase shift related to the time shift and that of the CEP can be clearly distinguished.
Collapse
|
14
|
|
15
|
Hu WH, Shu CC, Han YC, Yuan KJ, Cong SL. Efficient enhancement of field-free molecular orientation by combining terahertz few-cycle pulses and rovibrational pre-excitation. Chem Phys Lett 2009. [DOI: 10.1016/j.cplett.2009.09.051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
16
|
Hu WH, Shu CC, Han YC, Yuan KJ, Cong SL. Enhancement of molecular field-free orientation by utilizing rovibrational excitation. Chem Phys Lett 2009. [DOI: 10.1016/j.cplett.2009.04.055] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
17
|
Han YC, Yuan KJ, Hu WH, Cong SL. Control of photodissociation and photoionization of the NaI molecule by dynamic Stark effect. J Chem Phys 2009; 130:044308. [DOI: 10.1063/1.3067921] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
|