退火温度对宽带脉冲压缩光栅载体金属/介质多层高反膜的影响

分别以金(Au)作为金属层材料, 氧化铪(HfO₂)与氧化硅(SiO₂)作为高低折射率层材料, 利用物理气相沉积方法制备了用于宽带脉冲压缩光栅制作的金属/介质多层高反膜, 研究了退火温度对其表面均方根粗糙度、反射率及抗化学清洗破坏能力的影响。实验结果表明: 退火前后样品表面均方根粗糙度变化很小; 提高退火温度能提高金属/介质多层膜的抗化学清洗破坏能力, 但反射率会随之下降。250℃退火10 h后金属/介质多层膜不仅可以承受住化学清洗过程, 而且反射率下降也比较小, 可以作为金属/介质多层膜的最佳退火工艺。

Effect of Annealing Temperature on Metal/Dielectric Multilayers for Fabricating Broadband Pulse Compression Gratings

Metal/dielectric multilayers were prepared by physical vapor deposition process using gold as the metal material, HfO₂ and SiO₂ as high and low refractive index materials, respectively. These stacks were used to fabricate broadband pulse compression gratings. Influences of annealing temperature on the surface root-mean-square roughness, reflectivity and resistance to chemical cleaning damage were investigated. The experimental results indicated that surface root-mean-square roughness of these multilayers changed only slightly after annealing. Their resistance to chemical cleaning damage improved with the annealing temperature increase, whereas their reflectivity decreased. The metal/dielectric multilayers annealed at 250℃ for 10 h could not only endure the process of chemical cleaning, but also slightly decrease the reflectivity, suggesting that it is an optimal annealing process for metal/dielectric multilayers.