Field-free orientation dynamics of CO molecule by combining two-color shaped laser pulse with THz laser pulse train

In this paper, the field-free alignment of molecule ClCN is investigated with a terahertz few-cycle pulse (THz FCP) based on the time-dependent density matrix theory. It is shown that a high degree of molecular alignment can be obtained by changing the matching number of the THz FCP in both adiabatic and non-adiabatic regimes. The matching number can affect both the maximum value of the alignment and the time at which it is achieved. It is also found that a higher degree of alignment by the THz FCP can be achieved at lower intensity and there exists the optimization threshold of molecular alignment with the increasing of the field amplitude. Also found is the frequency sensitive region in which the degree of maximum alignment can greatly be enhanced through the modulation of the center frequencies of different THz FCPs. The investigation demonstrates that comparing with a THz single-cycle pulse, a better result of the field-free alignment can be created by a THz FCP at the constant rotational temperature of molecule.

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“….). Based on the rigid rotor approximation, the Hamiltonian of the molecule ClCN exposed to the laser field E(t) can be expressed as [42] Ĥ…”

Section: Description Of Methodsmentioning

confidence: 99%

Dynamics of molecular alignment steered by a few-cycle terahertz laser pulse

Cheng

Song

et al. 2022

Chinese Phys. B

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“…The maximum degree of molecular orientation achieved by a single-pulse depends on temporal duration and pulse peak intensity . Enhanced field-free molecular orientation can be obtained from a twocolor shaped laser pulse method and a time-delayed THz laser pulse train method [339].…”

Section: Pulse Trainmentioning

confidence: 99%

Orientation and Alignment Dynamics of Polar Molecule Driven by Shaped Laser Pulses

Nautiyal,

Devi,

Tyagi

et al. 2020

Preprint

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We review on the theoretical status of intense laser orientation and alignment-a field at the interface between intense laser physics and chemical dynamics with the potential applications ranging from high harmonic generation, nano-scale processing and control of chemical reactions. The evolution of the rotational wave packet and its dynamics leading to orientation and alignment is the topic of the present discussion. The major part of the article basically presents an overview on recent theoretical progress in controlling the orientation and alignment dynamics of a molecule by means of shaped laser pulses. The various theoretical approaches that lead to orientation and alignment ranging from static electrostatic field in combination with laser field(s), combination of orienting and aligning field, combination of aligning fields, combination of orienting fields, application of train of pulses etc. are discussed. It is focussed that the train of pulses proves to be quite efficient in increasing the orientation or alignment of a molecule without causing the molecule to ionize. The orientation and alignment both can occur in adiabatic and non-adiabatic conditions with the rotational

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“…Although Liu et al [28] studied the molecular orientation by combining an STRT (slow turn-on and rapid turn-off) with THz laser pulse, the maximum degrees of molecular orientation by adding THz pulse has not been improved effectively, and the negative orientation has not been discussed in their work either. Dang et al [29] orientated the molecules by combining a nonresonant shaped laser pulse with a THz laser pulse train, but they paid the most attention to the effect of pulse number on orientation.…”

Section: Introductionmentioning

confidence: 99%

Field-free molecular orientation steered by combination of super-Gaussian and THz half-cycle laser pulses*

Cheng¹,

Song²,

Meng³

2019

Chinese Phys. B

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The molecular orientation created by laser fields is important for steering chemical reactions. In this paper, we propose a theoretical scheme to manipulate field-free molecular orientation by using an intense super-Gaussian laser pulse and a time-delayed terahertz half-cycle pulse (THz HCP). It is shown that the degree of field-free orientation can be doubled by the combined pulse with respect to the super-Gaussian pulse or THz HCP alone. Moreover, different laser intensities, carrier envelop phases, shape parameters, and time delays have great influence on the positive and negative orientations, with other conditions unchanged. Furthermore, it is indicated that the maximum degree and direction of molecular orientation can be precisely controlled by half of the duration of the super-Gaussian pulse. Finally, by adjusting the laser parameters of the super-Gaussian laser pulse and THz HCP, the optimal results of negative orientation and corresponding rotational populations are obtained at different temperatures of the molecular system.

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Field-free orientation dynamics of CO molecule by combining two-color shaped laser pulse with THz laser pulse train

Cited by 8 publications

References 48 publications

Dynamics of molecular alignment steered by a few-cycle terahertz laser pulse

Dynamics of molecular alignment steered by a few-cycle terahertz laser pulse

Orientation and Alignment Dynamics of Polar Molecule Driven by Shaped Laser Pulses

Field-free molecular orientation steered by combination of super-Gaussian and THz half-cycle laser pulses*

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