强激光辐照对无氢DLC膜光学特性的影响

为了探索类金刚石薄膜激光损伤的原因,研究了在激光作用下类金刚石薄膜的光学性能和结构的变化.采用非平衡磁控溅射(Unbalance Magnetron Sputtering,UBMS)在Si基底上制备了无氢类金刚石薄膜(Diamond-Like Carbon,DLC).利用激光损伤测试系统对无氢DLC薄膜进行激光辐照,激光波长为1064 nm,脉宽为10 ns.对辐照前后进行了透过率、激光损伤阈值(Laser-Induced Damage Threshold,LIDT)及拉曼光谱测试.研究结果表明:当激光辐照能量密度从0升高至0.93 J/cm2时,透过率峰值从67.06％降至58.27％;当激光能量密度一定,脉冲次数从0增加至3时,透过率峰值从67.06％降至57.65％,LIDT从0.94降至0.50 J/cm2,通过对Raman光谱进行分析认为辐照过程中sp3向sp2的转变是导致透过率和LIDT降低的重要原因.

Optical Properties of Hydrogen Free DLC Films Radiated by High Power Laser

In order to explore the real causes of laser damage of diamond-like film, the change of the optical properties and its structure under the laser action were studied. Hydrogen-free diamond-like carbon （DLC） films were deposited by unbalanced magnetron sputtering on Si substrate. The films were radiated by the system which was used to detect the laser-induced damage threshold （LIDT）, laser wavelength and pulse width were 1064 nm and 10 ns respective. The transmittance, LIDT and Raman spectrum of DLC before and after radiation were examined. It is found that as laser fluence rises from 0 to 0. 93 J/cm^2 ,the transmittance peak reduces from 67. 06% to 58. 27%,and as laser pulse number rises from 0 to 3,the transmittance peak reduces from 67. 06% to 57.65%, LIDT reduces from 0. 94 to 0. 50 J/cm^2. It is concluded that sp3 transforming sp2 is the important reason for the decreased transmittance and LIDT through the analysis of Raman spectrum.