Matsumura Tomotake, Young Karl, Wen Qi, Hanany Shaul, Ishino Hirokazu, Inoue Yuki, Hazumi Masashi, Koch Jürgen, Suttman Oliver, Schütz Viktor
Appl Opt. 2016 May 1;55(13):3502-9. doi: 10.1364/AO.55.003502.
We report on the first use of laser ablation to make submillimeter, broadband, antireflection coatings (ARCs) based on subwavelength structures (SWSs) on alumina and sapphire. We used a 515 nm laser to produce pyramid-shaped structures with a pitch of about 320 μm and a total height of near 800 μm. Transmission measurements between 70 and 140 GHz are in agreement with simulations using electromagnetic propagation software. The simulations indicate that SWS-ARCs with the fabricated shape should have a fractional bandwidth response of Δν/ν=0.55 centered on 235 GHz for which reflections are below 3%. Extension of the bandwidth to both lower and higher frequencies, between a few tens of gigahertz and a few terahertz, should be straightforward with appropriate adjustment of laser ablation parameters.
我们报道了首次使用激光烧蚀在氧化铝和蓝宝石上制作基于亚波长结构（SWS）的亚毫米级宽带减反射涂层（ARC）。我们使用515 nm激光制作出间距约为320μm、总高度近800μm的金字塔形结构。70至140 GHz之间的传输测量结果与使用电磁传播软件进行的模拟结果一致。模拟表明，具有所制造形状的SWS-ARC在中心频率235 GHz处应具有Δν/ν = 0.55的分数带宽响应，此时反射率低于3%。通过适当调整激光烧蚀参数，将带宽扩展到几十吉赫兹到几太赫兹的更低和更高频率应该是很直接的。
