高功率激光放大器片腔洁净度实验研究

 在氙灯放电泵浦过程中，放大器片腔内材料在高强度氙灯光辐照下，存在显著的热解过程，产生大量的微米级悬浮粒子。在两种实验条件下对粒子数进行了测量：一是放大器氙灯泵浦结束之后悬浮粒子的自然消散过程；二是氙灯泵浦结束之后利用大气流量的超纯氮气冲洗片腔之后的粒子数测量。研究结果表明，正常情况下，氙灯泵浦结束后片腔洁净度达到了10~50万级气溶胶的水平(在粒子直径Φ 0.5 μm的水平上)。利用大气流量的超纯N₂气冲洗片腔能够在短时间内显著地提高片腔的洁净度。

Investigation of slab cavity cleanliness of high power laser amplifiers

Experimental research of the slab cavity cleanliness of high power laser amplifiers is presented in this paper. The results indicate that materials within the slab cavity are readily pyrolyzed due to flashlamp high irradiance, and thus produce large quantity of airborne particles at the scale of micrometers. Experiments are carried out under two conditions, one of which measures the particles without nitrogen flushing, and the other measures the particles with several minutes of high flow nitrogen flushing slab cavity immediately after flashlamp pumping. Experimental results show that class100,000～500,000 aerosols (diameter ≥0.5μm) are usually produced immediately after the flashlamp firing. Flushing of the slab cavity with a high flow of filtered nitrogen can significantly improve the cavity cleanliness within a few minutes.