Mangote B, Gallais L, Zerrad M, Lemarchand F, Gao L H, Commandré M, Lequime M
Institut Fresnel, CNRS, Aix-Marseille Université, Ecole Centrale Marseille, Marseille, France.
Rev Sci Instrum. 2012 Jan;83(1):013109. doi: 10.1063/1.3677324.
A laser damage test facility delivering pulses from 100 fs to 3 ps and designed to operate at 1030 nm is presented. The different details of its implementation and performances are given. The originality of this system relies the online damage detection system based on Nomarski microscopy and the use of a non-conventional energy detection method based on the utilization of a cooled CCD that offers the possibility to obtain the laser induced damage threshold (LIDT) with high accuracy. Applications of this instrument to study thin films under laser irradiation are presented. Particularly the deterministic behavior of the sub-picosecond damage is investigated in the case of fused silica and oxide films. It is demonstrated that the transition of 0-1 damage probability is very sharp and the LIDT is perfectly deterministic at few hundreds of femtoseconds. The damage process in dielectric materials being the results of electronic processes, specific information such as the material bandgap is needed for the interpretation of results and applications of scaling laws. A review of the different approaches for the estimation of the absorption gap of optical dielectric coatings is conducted and the results given by the different methods are compared and discussed. The LIDT and gap of several oxide materials are then measured with the presented instrument: Al(2)O(3), Nb(2)O(5), HfO(2), SiO(2), Ta(2)O(5), and ZrO(2). The obtained relation between the LIDT and gap at 1030 nm confirms the linear evolution of the threshold with the bandgap that exists at 800 nm, and our work expands the number of tested materials.
介绍了一种激光损伤测试设备，其能输出脉宽从100飞秒到3皮秒的脉冲，设计工作波长为1030纳米。给出了其实现方式和性能的不同细节。该系统的独特之处在于基于诺马斯基显微镜的在线损伤检测系统以及使用基于冷却电荷耦合器件的非常规能量检测方法，这使得高精度获取激光诱导损伤阈值（LIDT）成为可能。介绍了该仪器在研究激光辐照下薄膜方面的应用。特别研究了熔石英和氧化物薄膜中亚皮秒损伤的确定性行为。结果表明，0 - 1损伤概率的转变非常尖锐，在几百飞秒时LIDT具有完美的确定性。介电材料中的损伤过程是电子过程的结果，解释结果和应用比例定律需要诸如材料带隙等特定信息。对估计光学介电涂层吸收带隙的不同方法进行了综述，并比较和讨论了不同方法给出的结果。然后用该仪器测量了几种氧化物材料的LIDT和带隙：Al(2)O(3)、Nb(2)O(5)、HfO(2)、SiO(2)、Ta(2)O(5)和ZrO(2)。在1030纳米处获得的LIDT与带隙之间的关系证实了阈值随800纳米处存在的带隙呈线性变化，并且我们的工作扩展了测试材料的数量。
