Laser pulse compression towards collapse and beyond in plasma

Tools

Wilson, Thomas Cunningham and Li, Fei-yu and Weng, Su-Ming and Chen, Min and McKenna, Paul and Sheng, Zheng-Ming (2019) Laser pulse compression towards collapse and beyond in plasma. Journal of Physics B: Atomic, Molecular and Optical Physics, 52 (5). 055403. ISSN 0953-4075 (https://doi.org/10.1088/1361-6455/ab0132)

[thumbnail of Wilson-etal-JPB-2019-Laser-pulse-compression-towards-collapse-and-beyond-in-plasma]
Preview
 Text. Filename: Wilson_etal_JPB_2019_Laser_pulse_compression_towards_collapse_and_beyond_in_plasma.pdf
Accepted Author Manuscript
License: Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 logo
Download (6MB)| Preview

Abstract

The dynamics of three-dimensional (3D) compression of ultrashort intense laser pulses in plasma is investigated theoretically and numerically. Starting from the slowly-varying envelope model, we derive equations describing the spatiotemporal evolution of a short laser pulse towards the singularity, or collapse, based on the variational method. In particular, the laser and plasma conditions leading to spherical compression are obtained. 3D particle-in-cell simulations are carried out to verify these conditions, which also enable one to examine the physical processes both towards and beyond the pulse collapse. Simulations suggest that the laser pulse can be spherically compressed down to a minimum size of the order of the laser wavelength, the so called lambda-cubic regime. The compression process develops over twice as fast in simulation than is predicted by the envelope model, due to the simplified nature of the latter. The final result of this process is pulse collapse, which is accompanied with strong plasma density modulation and spectrum broadening. The collapse can occur multiple times during the laser pulse propagation, until a significant part of the pulse energy is dissipated to electron acceleration by the laser ponderomitve force. It is also shown that a strong external DC magnetic field applied along the laser propagation direction can enhance the rate of compression for circularly-polarised laser pulses, when compared to an unmagnetised plasma, allowing access to strong compression and focusing in the low-density and low-amplitude regime.

ORCID iDs

Wilson, Thomas Cunningham ORCID logoORCID: https://orcid.org/0000-0002-6140-7045, Li, Fei-yu ORCID logoORCID: https://orcid.org/0000-0001-8638-8779, Weng, Su-Ming, Chen, Min, McKenna, Paul ORCID logoORCID: https://orcid.org/0000-0001-8061-7091 and Sheng, Zheng-Ming ORCID logoORCID: https://orcid.org/0000-0002-8823-9993;
  • Item type:Article
    ID code:66729
    Dates:
    Date
    Event
    13 February 2019
    Published
    23 January 2019
    Published Online
    23 January 2019
    Accepted
    Subjects:Science > Physics > Plasma physics. Ionized gases
    Department:Faculty of Science > Physics
    Depositing user: Pure Administrator
    Date deposited:25 Jan 2019 05:20
    Last modified:15 Dec 2024 01:27
    URI:https://strathprints.strath.ac.uk/id/eprint/66729
CORE (COnnecting REpositories)