光学薄膜的激光损伤阈值是衡量光学薄膜抗激光损伤能力的重要参数，而测量损伤阈值的关键是准确地判定损伤是否发生。为解决常见损伤判别方法的不足，尤其是误判问题，提出了一种新的判别方法闪光光谱峰值位法。激光辐照薄膜时薄膜表面发生闪光，利用光谱仪接收闪光光谱，然后提取光谱的峰值位。由于薄膜元素与大气中的元素种类存在本质差异，而且这些元素的光谱峰值位是确定的，不会因测试条件的变化而改变。以光谱峰值位存在的差异作为判断薄膜损伤的依据，可以消除大气闪光造成的误判，判别准确度高、作用时间短、材料范围宽、易于实现。

The laser damage threshold of optical thin films is an important parameter to measure the optical thin film laser induced damage capacity, and the key of measuring the damage threshold is to accurately determine the damage whether or not occurred. To eliminate disadvantage of common identified damage method, especially in a miscarriage, a new identification method based on plasma spectrum to determine the optical film damage is proposed in this paper. The flash happens when laser irradiates the surface of thin film, and the flash spectrum is received by spectrometer. Then the spectral peak bit is extracted. Because of the essential differences between thin film elements and atmosphere elements, the certain spectral peak bits will not change with the change of test conditions. As the differences of spectral bits is used to identify the thin film damage, the advantage of this method is the ability to eliminate the atmospheric flashes caused by the miscarriage of justice, high accuracy of discrimination, short duration of action, a wide range of materials and implement easily.