论文标题
蓝宝石上的宽带，毫米波抗反射结构，用femto秒激光烧杯
Broadband, millimeter-wave anti-reflective structures on sapphire ablated with femto-second laser
论文作者
论文摘要
我们在蓝宝石上设计，制造和测量的抗反流涂层（ARC），该涂层在毫米波带中具有116％的分数带宽和至少97％的传播。 ARC基于模式性金字塔样的亚波长结构（SWS），该结构（SWS）使用在1030 nm处运行的15 W FEMTO秒激光烧蚀。两个圆盘的每一侧都用SWS制造，其螺距为0.54毫米，高度为2 mm。平均消融量删除率为1.6毫米$^{3} $/min。两盘三明治的测量显示出43至161 GHz之间的97％的传播。我们表征了由于不对称的SW引起的差分传输引起的仪器极化（IP）。我们发现，在正常入射率下，两个圆盘三明治RMS IP的适当比对预计为0.07％，入射角下的少于0.6％。这些结果表明，SWS在蓝宝石上的激光消融和其他硬质材料（例如氧化铝）是制造宽带弧的有效方法。
We designed, fabricated, and measured anti-reflection coating (ARC) on sapphire that has 116% fractional bandwidth and transmission of at least 97% in the millimeter wave band. The ARC was based on patterning pyramid-like sub-wavelength structures (SWS) using ablation with a 15 W femto-second laser operating at 1030 nm. One side of each of two discs was fabricated with SWS that had a pitch of 0.54 mm and height of 2 mm. The average ablation volume removal rate was 1.6 mm$^{3}$/min. Measurements of the two-disc sandwich show transmission higher than 97% between 43 and 161 GHz. We characterize instrumental polarization (IP) arising from differential transmission due to asymmetric SWS. We find that with proper alignment of the two disc sandwich RMS IP across the band is predicted to be 0.07% at normal incidence, and less than 0.6% at incidence angles up to 20 degrees. These results indicate that laser ablation of SWS on sapphire and on other hard materials such as alumina is an effective way to fabricate broad-band ARC.
