Picocoulomb electron bunches emitted from the metal tip on Ti:Sa femtosecond laser irradiation

The electron emission from a metal tip under the irradiation of a femtosecond laser pulse with μJ energy level is studied. It was shown that the electron bunch charge emitted from the cathode first increases with increasing laser pulse energy proportionally to the fourth power and then the dependence saturates. The maximum value of the emitted charge is on the order of 10 pC.