Double-peak emission of hot electrons generated by femtosecond laser interaction with solid targets.

Double-peak emission of hot electrons has been observed in the interaction of a 60-fs, 125-mJ, 800-nm, p-polarized laser pulse with Al targets. One peak in the specular direction is due to the reflected laser light, which excites a plasma wave to accelerate electrons. The other peak, which is more consistent with theories of Phys. Plasmas 6, 2855 (1999)] and Phys. Rev. Lett 82, 743 (1999)], is produced by the resonance absorption at approximately 15 degrees from the target normal.