256个飞秒脉冲的时域相干合成
摘要
Objective High -pulse energy femtosecond lasers with high repetition rates are required in numerous areas such as high -field physics, high -energy terahertz pulse generation, high -fluence attosecond pulse generation, and material processing.Femtosecond pulses with energies above millijoules are generally achieved using solid -state lasers.Heat -related problems limit solid -state laser operation at high average powers.By contrast, fiber lasers are attractive owing to their compactness, flexibility, and low cost.However, the pulse energy of the fiber lasers is limited by their nonlinearity and optical damage.Coherent stacking of numerous femtosecond pulses is a promising technique for generating high pulse energy at a high repetition rate.Temporal stacking can be achieved using cavity stacking, delay -line stacking, or a hybrid of the two.Delay line stacking uses pulses with a repetition rate of 80-100 MHz, corresponding to a pulse separation of 12.5-10.0ns, or several delay lines with the lengths of multiple times of