采用自滤波振荡，腔内起偏，行波放大的铜激光系统，获得了发散角接近衍射极限，偏振度为97%，绿光输出功率为8.8 W的铜激光，并与非稳腔振荡行波放大的铜激光系统进行了比较。

Adopting an oscillator-amplifier copper vapor laser system with a self-filtering unstable resonator, we obtained laser output of 8. 8 W at 510. 6 nm with near diffractionlimited divergence and polarization degree of 97 %. Meantime, we compared two oscillatoramplifier systems containing a self-filtering unstable resonator and a negative branch unstable resonator, respectively.