利用现有窄带激光传输模拟软件SG99和宽带激光传输模拟软件CPAP，以及自编的一维光脉冲传输放大的逆算程序，评估了原型装置在主放基本结构不动的情况下激光脉冲由窄带改为宽带，实现数十nm宽带条件数kJ的输出能力。宽带下增益窄化效应显现，对光谱增益窄化补偿也进行了研究。结果表明，为了补偿增益窄化效应，在3 J主放注入能量下通过对光谱整形可满足系统2000~3000 J的输出，但损失约40%的注入能量。考虑到这一因素，预放级至少要有5 J的输出能力。研究结果指导了数十nm宽带倍频激光驱动实验系统研制实施方案。

In the SG-Ⅲ prototype laser facility, if the laser’s narrow bandwidth is adjusted to broadband while maintaining the main configuration, the energy output will decrease. This article evaluates the kilojoule energy output capability of tens-nm broadband laser, using numerical simulation softwares SG99 and CPAP respectively for narrowband and broadband laser propagation and amplification, and the program of one-dimension reverse propagation and amplification. The result shows the growing of gain-narrowing effect under broadband condition. The compensation of gain-narrowing is studied. With compensation, while losing 40% of the input energy, the output energy can reach 2 000~3000 J under 3 J injection. Hence there should be at least 5 J energy output after the preamplifier. This research will conduct the implementation plans for tens-nm broadband 2ω laser system.