J.-C. Gauthier, et al.
J. Phys. IV France 133 (2006) 479-485
Modulation of harmonic emission spectra from intense laser-plasma interactionsT.J.M. Boyd1 and R. Ondarza-Rovira2
1 Centre for Physics, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
2 ININ, A.P. 18-1027, México 11801, D.F., Mexico
We report results from a series of PIC simulations carried out to investigate the interaction of intense laser light with overdense plasma and in particular, aspects of the harmonic emission spectrum generated in these interactions. Recent observations of emission in this range by Watts et al.  show emission above the 20th harmonic extending to the 37th with conversion efficiencies of order 10-6 with this spectrum showing distinct, if variable, modulation of between two and four harmonics. This spectral feature proved highly sensitive to the incident intensity, with more pronounced modulation at higher intensities. These authors also reported results from a set of model PIC simulations which showed a modulated emission spectrum across the entire harmonic range, but with a wider modulation bandwidth.
© EDP Sciences 2006