脉冲激光放大器双程放大特性的理论研究

本文从建立脉冲激光器双程放大输运方程出发,理论上研究了双程放大输出脉冲特性。导出了输入脉冲持续时间t_p小于双程放大间隔时间t_o条件下双程放大过程的瞬态解和能量增益系数公式。在相同输入脉冲能量下,双程放大能量增益系数随t_p的增加或t_o的减小而下降。双程放大同单程放大比较结果表明,在小信号脉冲输入下,双程放大接近于具有两倍增益介质长度的单程放大。而在强饱和时,则相当于具有相同增益介质长度的单程放大。

Theoretical Studies of Double-Pass Amplification Properties in Pulsed Laser Amplifier

Based on the establishment of double-pass amplification transportation equationsin pulsed laser amplifier, the theorectical investigation of output pulse characteris -tics of double--pass amplification is presented. The temporal solutions to double-passamplification process and the formula for double--pass amplification energy gain co-efficient K_d are derived under the condition of input pulse duration t_p less than do-uble--pass amplification interval time t_o. We find K_d decreases with the increase oft_p or the decrease of t_o for same input pulse energy. The results of double--pass am--plification compared with single--pass amplification show that double--pass amplifi-cation is equal to single--pass amplification with double long gain medium under thesmall signal input, and same as single--pass amplification with same long gain medi-um when input pulse signal is strong.