实验发现光学材料的损伤与激光波长、材料特性、激光脉宽等因素有关，而且光学材料损伤的最终态是不一样的，这个态可以是熔化、碎裂或蒸发。为了解释这些现象，从材料的热传导方程出发半定量地讨论了光学材料损伤机理，指出了一个关键参数决定了激光诱发损伤与激光脉宽τp的关系，它就是光学材料内的夹杂物把热量传递给光学材料体所需时间τ。在τpτ时，损伤阈值由激光辐射强度决定；在τpτ时，损伤阈值由激光辐射能量密度决定。

Scientific experiments show that damage to optical materials is related with factors like laser wavelength, material properties, laser pulse width, etc. The final stage of damage is various, which can be melting, crack and ablation. In an effort to explain these phenomena, we run a semi-quantitative discussion on the optical material damage mechanism regarding the thermal conduction equation, presenting a key parameter that determines the relationship between laser induced damage and laser pulse width τp—the time τ it takes for the inclusion within the optical material to transfer its heat to the body. When τpτ, the damage threshold is determined by laser radiation intensity; when τpτ, the damage threshold is determined by laser radiation energy density.