数值计算了基模高斯光束经有限口径的均匀加宽放大介质后，其M2Q因于随输入光与放大器各参数的变化的规律。计算表明:激光放大均使光束质量变坏，且集中在放大器口径a与高斯光束的ω的比值处在1～4之间时；低的输入光强，小的放大器总增益，和大的饱和光强有利于保持放大器输出光的光束质量。

Numerical simulating the change of M2Q of a TEMoo Gaussian beam after homogeneously saturating amplification versus parameters of the input beam and the amplifier was performed. Calculation shows that, laser amplification always deteriorates the input beam quality, especially when the ratio of the amplifier bore diameter a to the spot size ω of the Gaussian beam ranges about 1～ 4. To get an amplified laser beam with better beam quality, low input intensity, low total gain and large saturation intensity of theamplifier is prefered.