Regular Article

Relativistic longitudinal self-compression of ultrashort time-domain hollow Gaussian pulses in plasma

¹ Institute of Optics, Department of Physics, Zhejiang University, Hangzhou 310027, P.R. China
² Center for Optics and Optoelectronics Research, College of Science, Zhejiang University of Technology, Hangzhou 310023, P.R. China

^a e-mail: zhaoyingwang@zju.edu.cn

Received: 24 March 2017
Received in final form: 23 August 2017
Published online: 17 October 2017

Abstract

We report a study on dynamical evolution of the ultrashort time-domain dark hollow Gaussian (TDHG) pulses beyond the slowly varying envelope approximation in homogenous plasma. Using the complex-source-point model, an analytical formula is proposed for describing TDHG pulses based on the oscillating electric dipoles, which is the exact solution of the Maxwell’s equations. The numerical simulations show the relativistic longitudinal self-compression (RSC) due to the relativistic mass variation of moving electrons. The influences of plasma oscillation frequency and collision effect on dynamics of the TDHG pulses in plasma have been considered. Furthermore, we analyze the evolution of instantaneous energy density of the TDHG pulses on axis as well as the off axis condition.