气压对吸气式激光推进冲量耦合系数的影响

保持CO2激光的单脉冲能量为61.4~64.6 J，采用高精度冲击摆系统进行了不同气压下吸气模式激光推进冲量耦合系数的实验测试，分析了对应的高度特性。结果表明:气压为2.8×104～1×105 Pa，即距离地面0～10 km时，冲量耦合系数大约3.5×10-4 N·s·J-1，上下波动幅度低于5%；气压低于2.8×104 Pa，即高度大于10 km时，冲量耦合系数呈二次曲线显著下降；当气压降至1×103 Pa，即距离地面约31 km高度时，耦合系数仅为9.7×10-5 N·s·J-1。

Beam quality of unstable resonator of TEA CO2 coaxial output laser with vortex tube cooling system

The beam quality of unstable resonator of TEA CO2 coaxial output laser is deteriorated remarkably by the thermal accumulation of the output coupler.In order to improve the beam quality, a vortex tube cooling system of output coupler was adopted.The divergence angle was measured at an average pulse energy of 18.3 J under condition of different frequency with and without using the vortex tube cooling system at real time,and the times-diffraction-limited factor was studied.The results show that the times-diffraction-limited factor was changed from 3.52 to 6.94 without the vortex tube cooling system and from 3.50 to 3.88 with the cooling system at 3 Hz during an operating time of 300 s.