Generation of a single attosecond pulse from an overdense plasma surface driven by a laser pulse with time-dependent polarization

The influence of time-dependent polarization on attosecond pulse generation from an overdense plasma surface driven by laser pulse is discussed analytically and numerically. The results show that the frequency of controlling pulse controls the number and interval of the generated attosecond pulse, that the generation moment of the attosecond pulse is dominated by the phase difference between the controlling and driving pulses, and that the amplitude of the controlling pulse affects the intensity of the attosecond pulse. Using the method of time-dependent polarization, a “single” ultra-strong attosecond pulse with duration τ ≈ 8.6 as and intensity I ≈ 3.08 × 10²⁰ W·cm^-2 can be generated.