An accurate method for investigation of laser-induced damage of optical component at 351nm

摘要

A multipurpose laser damage test facility delivering pulses from Ins to 20ns and designed to output energy 40 Joule at 351nm is presented. The laser induced damage threshold (LIDT) measurement and test procedure are performed. The original system consist of the online detection system based on the microscopy and an energy detection device based on the scientific grade Charge Coupled Device (CCD) which provides the method to measure the LIDT with high accuracy. This method is an efficient way that allows measuring a small area fluence which the defect exposed. After complete test procedure and data treatment the damage position of the defect has been found. Then we can obtain the local fluence of small area when the damage occurred. This procedure provides a straightforward means of laser-damage threshold obtained from the test method. Damage correlation of measures is discussed in connection with present theoretical understanding of laser damage phenomenon. The damage process in transparent dielectric materials being the results of complex processes involving multi-photon ionization; avalanche ionization; electron-phonon coupling; and thermal effects; Those complex processes lead to the damage on the optical surface; We performed a method to measure the local fluence which defects irradiated with high accurate.