What is it about?

This research explores a cutting-edge technique to generate attosecond pulses. We used a combination of powerful lasers and special mathematical models to study how these attosecond pulses are created in a molecule called carbonyl sulfide. By adjusting the strength of one of the lasers, we were able to control the direction and intensity of these pulses. This breakthrough allows us to make pulses of light that are almost perfectly circular and change their shape as needed. We also found that a particular part of the molecule plays a crucial role in creating these pulses. This research has opened the door to producing controlled attosecond pulses, which could have applications in ultrafast science and technology.

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Why is it important?

This research represents a significant advancement in the field of ultrafast dynamics and coherent light sources. By applying the Time-Dependent Density Functional Theory (TDDFT), the study delves into High-Order Harmonic Generation (HHG) in carbonyl sulfide molecules. The use of a linearly polarized infrared laser combined with a weakly orthogonal Terahertz field allows for precise control over electron movement, leading to the creation of near-circularly polarized attosecond pulses. Additionally, the manipulation of the carrier-envelope phase of the IR laser pulse enables dynamic adjustments to the attosecond pulse's ellipticity. The research underscores the pivotal role of a specific molecular orbital, HOMO b, in harmonic emission through sophisticated simulations. The innovative aspect lies in the effective modulation of harmonic intensity by the Terahertz field, which governs the motion of ionized electrons, resulting in interference effects upon recombination with different atoms. This breakthrough sets the stage for generating isolated attosecond pulses with controllable polarization, offering tremendous potential for applications in various fields of optics and ultrafast dynamics.


This research achieves precise control over electron movements, enabling the creation of near-circular attosecond pulses. This breakthrough holds immense potential across various scientific and technological domains. Notably, the ability to finely manipulate attosecond pulse properties is crucial in attosecond science, where probing ultrafast processes in matter requires tailored light pulses. The study's emphasis on specific molecular orbitals and modulation of ionized electron motion significantly enriches our comprehension of these intricate phenomena.

Tingting Fu
Institute of Atomic and Molecular Physics, Jilin University

Read the Original

This page is a summary of: Circularly polarized attosecond light generation from OCS molecules irradiated by the combination of linear polarized infrared and orthogonal terahertz fields, The Journal of Chemical Physics, October 2023, American Institute of Physics, DOI: 10.1063/5.0167522.
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