等离子体增强化学气相沉积(PECVD)技术在制备高激光损伤阈值的激光薄膜和渐变折射率结构的光学薄膜方面有独特的优点。通过大量的工艺研究,人们掌握了调控光学薄膜材料折射率和降低消光系数的方法。目前已知薄膜的最低折射率为1.16±0.01(632.8 nm波长处),有效拓展了薄膜材料的折射率范围。当薄膜的消光系数小于10 -3时,薄膜折射率的可变范围为1.33~2.06,基本满足光学薄膜设计和制造的需求,且获得了大量中间折射率的制备工艺,基本满足光学薄膜设计和制造的需求。此外,薄膜制备工艺的稳定性和重复性也通过实验得到了验证。目前,PECVD技术已被用于制备多层光学薄膜,如减反膜、高反膜、Rugate滤光片、陷波滤光片,薄膜的光谱特性及抗激光损伤特性明显优于传统光学薄膜。特别是在渐变折射率薄膜的制造领域,PECVD技术有广阔的工程应用前景。

Plasma-enhanced chemical vapor deposition (PECVD) technique has unique advantages in the preparation of laser thin films with high laser-induced damage threshold and optical thin films with graded-index profile. Through huge amounts of researches in deposition parameters, people have mastered the methods of adjusting the refractive index and reducing the extinction coefficient of the optical thin films. The lowest refractive index is currently known to be 1.16±0.01 (at the wavelength of 632.8 nm), which expands the refractive index range of optical thin films materials. When the extinction coefficient of the films is less than 10 ^-3, the variable range of the refractive index is 1.33-2.06, and a large number of intermediate refractive indices with different values are obtained, which basically meets the requirements of the design and manufacture of the optical thin films. Besides, the stability and repeatability of the technique have been verified by experiments. For now, the PECVD technique has been used to prepare multilayer films. Various optical films, such as anti-reflection films, high reflection films, Rugate filters, and notch filters, have been successfully prepared, which have a higher ability on laser protection and better spectral characteristics than those conventional optical thin films deposited by physical vapor deposition technique. PECVD technique has a widely applicable prospect of engineering, especially for the deposition of graded-index optical thin films.