Table 1.

Speed of a moving intensity wave, together with the matching electron speed and energy, for different combinations of laser harmonics

Laser harmonics	Electron speed, c	Electron energy, keV
2ω, 3ω	0.2	10
ω, 2ω	0.33	31
ω, 3ω	0.5	79
ω, 4ω	0.6	128