利用波长可调谐光学参量振荡器(OPO)测量了液氧在1580 nm波长附近的小信号增益，在1579.9 nm波长处获得了0.12 cm-1的小信号增益，并获得了从1579.2 nm至1580.8 nm的小信号增益分布情况。 正增益的获得表明液氧在小信号增益层面上满足作为一种高能激光工作介质的要求。还需要对实验条件进行全面的参数优化，以尽可能提高小信号增益。

The small signal gain of the liquid oxygen around 1580 nm is measured using a tunable optical parametric oscillator (OPO) system. A small signal gain of 0.12 cm-1 is obtained at the wavelength of 1579.9 nm. The profile of small signal gain from 1579.2 nm to 1580.8 nm is also presented. The high positive gain indicates that the liquid oxygen is a potential medium for high energy laser. A comprehensive parameter optimization must be done in order to improve the small signal gain.