横向电场下的类金刚石薄膜激光损伤

类金刚石(DLC)薄膜在红外区有很高的透过率,但激光损伤阈值低,严重限制了其应用领域。采用直接在DLC薄膜上沉积Ti电极,基于激光损伤阈值(LIDT)测试平台,用1-on-1零几率损伤法,研究了在不同偏置电场下DLC薄膜损伤阈值及损伤形貌的变化。发现电场强度从0增加到700V/cm,损伤阈值明显增大;进一步增大偏置电场,损伤阈值相对不变。分析认为偏置电场改变了激光辐照DLC薄膜区域的光生载流子漂移速度,减小了DLC薄膜的局部热累积,减缓了薄膜的石墨化进程,提高了DLC薄膜的抗激光损伤阈值。

Laser-induced damage of diamond-like carbon films with horizontal electric field

Diamond-like carbon (DLC) films are widely used in infrared region. However, DLC is prone to laser damage, which fetters the films usage in infrared high power laser systems and laser protection systems. The laser-induced damage threshold (LIDT) and damage morphology of DLC films were studied based on ISO11254 in different horizontal fields. Ti electrodes were deposited on the DLC films directly. It was found that the field intensity increased from 0 to 700 V/cm and the LIDT also increased; however, the LIDT was relatively unchanged over this horizontal field. Analysis suggests that the horizontal electric field changes the photo-induced carriers drift velocity in DLC films laser-induced area, then reduces the local heat accumulation, slows down the graphitization process in DLC films, and increases the laser-induced damage threshold of DLC film at last.