Behera Saraswati, Sarkar Swagato, Joseph Joby
Opt Lett. 2018 Jan 1;43(1):106-109. doi: 10.1364/OL.43.000106.
In this Letter we report for the first time, to the best of our knowledge, a phase spatial light modulator (SLM)-based interference lithography (IL) approach for the realization of hexagonally packed helical photonic structures with a submicrometer scale spatial, as well as axial, periodicity over a large area. A phase-only SLM is used to electronically generate six phase-controlled plane beams. These six beams from the front side and a direct central backside beam are used together in an "inverted umbrella" geometry setup to realize the desired submicrometer axial periodic chiral photonic structures through IL. The realized structures with 650 nm spatial and 353 nm axial periodicities on negative photoresist can be used as an optical filter and refractive index sensor, as evidenced from the FDTD-based simulation study on its optical properties. Further, the fabricated templates can be transferred to metals such as silver or aluminum for the realization of a metamaterial-based broadband circular polarizer ranging from 1 to 3.5 μm of near-infrared spectra.
在本信函中，据我们所知，我们首次报道了一种基于相位空间光调制器（SLM）的干涉光刻（IL）方法，用于在大面积上实现具有亚微米级空间以及轴向周期性的六边形排列螺旋光子结构。仅相位SLM用于电子生成六束相位控制的平面光束。这六束来自正面的光束和一束直接的中央背面光束在“倒伞”几何结构设置中一起使用，通过干涉光刻实现所需的亚微米轴向周期性手性光子结构。在负性光刻胶上实现的具有650纳米空间周期性和353纳米轴向周期性的结构可用作光学滤波器和折射率传感器，基于有限时域差分法（FDTD）对其光学特性的模拟研究证明了这一点。此外，制造的模板可转移到银或铝等金属上，以实现基于超材料的、覆盖1至3.5微米近红外光谱范围的宽带圆偏振器。
