Ionization of atom by combination of femtosecond laser pulses with phase accuracy

The electron energy distribution generated by tunneling ionization strongly depends on the polarization, wavelength, and peak intensity of the laser pulse. Controlling the initial electron energy distribution is important for applications such as pumping of soft-X-ray-lasers. We proposed a method to control the electron energy distribution by combining a pair of two orthogonally polarized laser pulses. We have investigated control of the polarizations of combined laser fields and ionization of atomic gas and the electron energy distribution generated by the combined pulse.