LAUSR

Abstract This paper reports relativistic motion and spatial emission distribution characteristics of single electron driven by a linearly polarized femtosecond tightly focused Gaussian laser pulse (FTFGLP) with various laser intensities. Utilizing the longitudinal ponderomotive force caused by the waist evolution of the FTFGLP and the induced acceleration and deceleration, we gain an oscillating energized electron naturally. After theoretical investigation and numerical calculation, it is concluded that with the laser intensity increasing, the electron drift and the maximal radial radius are growing in two speeds, but the opening angle in bifoliate radiation pattern (BRP) has a shrinking tendency. Furthermore, a novel phenomenon discovered firstly is that the ramification of location and number found in asymmetric BRP change all through, which appears in the bottom of BRP, disappears in BRP and reappears in the top of BRP, successively.