强脉冲CO2激光对红外材料的破坏现象

实验表明强激光对红外材料的破坏分为两种类型:烧蚀和冲击破坏。在空气中,光功率密度低于大气的光学击穿阈值时,以烧蚀为主。超过击穿阈值时,冲击破坏是主要的。在我们的实验条件下,用强激光辐照红外脆性材料的靶,靶极易产生微裂纹或粉碎性破坏,其破坏效果与激光的脉冲能量、功率密度、脉冲宽度,以及着靶面积有关。为了直观,文中给出了不少辐照损伤的照片。 关键词：

THE DAMAGE PHENOMENA ON INFRARED MATERIALS IRRADIATED BY INTENSE PULSED CO2 LASER

Experiments show that the materials damage effects irradiated by intense CO₂ laser can be divided into two types: the ablation and shock wave damage. The ablation is dominant when laser power density is lower than air breakdown threshold. When laser power density is higher than berakdown threshold, the shock wave damage becomes prime. Under our experimental condition, when strong laser beam irradiates on brittle targets such as infrared window materials MgF₂, KCl, Ge, etc., small cracks or broken pieces are formed very easily. The damage effects are related to pulse energy, power density, pulse width and irradiated area on the target. The photographs of radiation damage are also given.