Abstract
A diagnostic method for measuring nonlinear evolution of a laser wakefield by multiple sidebands of Raman scattering using probe laser light has been reported. In this paper, particle-in-cell simulations are used to demonstrate the validity of this probing method. The influence of plasma density, pump laser intensity, propagation length, and nonlinearity of the wakefield on probe laser light has been investigated. In particular, when trapping and acceleration of electrons occurs, the wing structure of the spectrum of probe laser light indicates the existence of highly relativistic electrons from which the injection fraction of the accelerated electrons can be obtained. Thus, this diagnostic method can be employed to measure laser wakefields conveniently for various purposes.
