Generation of an extreme ultraviolet supercontinuum in a two-color laser field.
We theoretically investigate the high-order harmonic generation in a helium atom with a two-color optical field synthesized by an intense 6 fs pulse at 800 nm and a relatively weak 21.3 fs pulse at 400 nm. When the frequency-doubled pulse is properly time shifted with respect to the fundamental pulse, an ultrabroad extreme ultraviolet supercontinuum spectrum with a 148 eV spectral width can be generated which directly creates an isolated 65 as pulse even without phase compensation. We explain this extraordinary phenomenon by analyzing maximum electron kinetic energies at different return times.
State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, CAS, P. O. Box 800-211, Shanghai 201800, China.
Zhinan
Z
Zeng
Ya
Y
Cheng
Xiaohong
X
Song
Ruxin
R
Li
Zhizhan
Z
Xu