激光损伤阈值是衡量光学元件性能的重要参数,而判别薄膜是否发生了损伤是准确测量薄膜激光损伤阈值的关键,因此研究薄膜损伤的判别方法具有重要意义。传统方法准确度低、操作复杂、人为因素影响大,提出了以等离子体冲击波压强特征为标准的判定薄膜损伤的新思路。以多种单层薄膜为例,搭建测试平台,利用传声器采集激光辐照薄膜产生的等离子体冲击波,将该数据与国标法测得的激光薄膜损伤阈值相对照,找到对应的等离子体冲击波压强阈值。实验表明,该方法判别速度快,操作简单,测试设备搭建方便,并可以实时监测,能够大大提高检测效率。

Laser damage threshold is one of the most important parameter to measure the performance of optical components. Judging whether the film is damaged or not is the key to accurately measure the laser damage threshold. It is significant to study the method of film damage identification. Considering some drawbacks of traditional methods, such as low accuracy, complex operation and large influence of human factors, a new method to determine the damage of thin film based on the characteristics of plasma shockwave pressure is presented in this paper. Taking a variety of single layer films as example, the data of the laser plasma shockwave by microphone on the testing platform is aquired. Comparing the data with the laser damage threshold by national standard method, the corresponding plasma shockwave pressure is found. Experimental results show that this method is fast, simple and easy to operate, and can be monitored in real time, which can greatly improve the detection efficiency.