Frequency-Modulated Pulse-Amplification Method for Reducing Pulse Shape Distortion

摘要： To reduce the laser pulse shape distortion accompanying the ampli?cation process and achieve an intended output pulse shape in the Nd:YAG ampli?er chain, we propose a frequency-modulated pulse-ampli?cation method. Assuming carrier-frequency-modulated seed pulses, we numerically simulate the pulse ampli?cation in an Nd:YAG ampli?er chain where severe distortion occurs. For the calculation, we develop a modi?ed Frantz-Nodvik equation, which enables two inputs with di?erent carrier frequencies. The simulation results indicate that the temporal contrast of the seed pulse needed to obtain a ?at output pulse shape is reduced by 16 - 25 dB when frequency modulation is applied.