The effect of 1-s irradiation of an uncooled polycrystalline CVD diamond plate by a focused cw CO₂ laser beam with a power density of 300 – 800 kW cm⁻² is investigated. The absorption coefficient of the sample at a power density of 800 kW cm⁻² is found to be 0.035 cm⁻¹ larger as compared with that at 300 kW cm⁻², which is related to the temperature dependence of its phonon-induced absorption with a change in temperature from 44 to 100 C. It is shown that polycrystalline diamond, in contrast to other optical materials, does not exhibit nonlinear (avalanche-like) rise in absorption at high CO₂-laser power densities, at least up to 800 kW cm⁻².

^{研究了功率密度为 300 – 800 kW cm -2的聚焦 cw CO} ₂激光束对未冷却多晶 CVD 金刚石板的 1 秒辐照效果。^{发现在 800 kW cm -2}的功率密度下样品的吸收系数比在 300 kW cm ^-2时的吸收系数大0.035 cm ^-1，这与其声子诱导吸收的温度依赖性有关温度从 44 到 100 摄氏度的变化。结果表明，与其他光学材料相比，多晶金刚石在高 CO ₂激光功率密度（至少高达 800千瓦厘米^-2。