重复频率脉冲激光辐照下光学薄膜元件 温升的有限元分析

文章采用有限元ANSYS程序分析了在重复频率脉冲激光辐照下光学薄膜元件表面的温度变化。结果表明激光脉宽相同时，重复频率越高，相同辐照时间薄膜元件表面温度累积就越大；占空比一样时，脉宽越大，相同辐照时间元件温升越高。重复频率表现出来的只是温度的累积效果，脉宽的影响效果远大于重复频率引起的温度累积。

The temperature rise in films at the repeat rate pulse laser irradiation determined based on finite element method

The temperature in various films irradiated by the repeat rate pulse laser is determined by ANSYS finite element software. The results indicate that with the same pulse duration, the temperature accumulation of films increases with the increase of the laser repeat rate at the same irradiation time. With the same ratio of the pulse duration to the laser period, the temperature rise increases with the pulse duration at the same irradiation time. The repeat rate affects only the temperature accumulation and of the two factors that affect the temperature accumulation, the pulse duration is more important. There are some limited declining of the temperature accumulation increase under repeat rate(f), pulse duration(tp) and irradiation time. With air cross-ventilation coefficient of 8W/(m2?℃), power density of 1.794×108 W/m2, facula laser spot diameter of 0.14mm, and the product of repeat rate and pulse duration less than 10-5, no temperature accumulation variation can be observed after one second of laser irradiation. With increased product of repeat rate and pulse duration, and longer temperature accumulation time, there will be more temperature rise.