摘要： 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. 其他題名： Appl Opt 出版者： United States 出版日期： 2016-05-01 出處： Applied Optics, 2016-05, Vol.55 (13), p.3502-3509 資源來源： Optica Publishing Group Journals 識別號： ISSN: 1559-128X 識別號： EISSN: 2155-3165 識別號： EISSN: 1539-4522 識別號： DOI: 10.1364/AO.55.003502 識別號： PMID: 27140362
