Hokari Ryohei, Takakuwa Kyohei, Shiomoto Kengo, Kuwano Genki, Kurihara Kazuma
Advanced Manufacturing Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba East, 1-2-1 Namiki, Tsukuba, Ibaraki, 305-8564, Japan.
Mitsubishi Gas Chemical Trading, Inc., KANDA SQUARE 15F, 2-2-1 Kanda-Nishikicho, Chiyoda-Ku, Tokyo, 101-0054, Japan.
Sci Rep. 2023 Aug 17;13(1):13387. doi: 10.1038/s41598-023-40511-z.
As society becomes smarter, advanced optical sensing and imaging technologies utilizing visible and near-infrared regions have become increasingly prevalent. Wire-grid polarizers, which are available for broadband electromagnetic waves, are effective in improving the signal-to-noise ratio of such optical systems and enabling more advanced object detection and analysis. However, to be implemented in everyday products, low-cost manufacturing methods must be developed while maintaining high-performance optical functions. To meet these requirements, we conducted an analysis of the geometry of wire-grid polarizers, and designed and developed a wire-grid polarizer with a nano-triangular wave-shaped structure that can be fabricated using general-purpose manufacturing equipment. Once the mould is prepared, this polarizer can be fabricated via nanoimprinting and metal deposition with a normal angle or electroless plating processes. The polarizer fabricated through electroless Ni plating achieves a transmittance of 40%, which is approximately 1.4 times higher than that achieved in a previous study using electroless Ni plating on a rectangular structure with the same period. In addition, the polarizer fabricated through normal angle Al deposition operates over a wide range of wavelengths from visible light to near-infrared, and achieves a polarization extinction ratio of 24 dB at a wavelength of 550 nm and a high transmittance of 81%. High-performance polarizers can be obtained through normal-angle deposition using general-purpose equipment in contrast to the oblique-angle deposition method employed in the manufacture of conventional rectangular structure-based wire-grid polarizers, thereby contributing to cost reduction and improved manufacturability.
随着社会变得更加智能化，利用可见光和近红外区域的先进光学传感和成像技术越来越普遍。可用于宽带电磁波的线栅偏振器，在提高此类光学系统的信噪比以及实现更先进的目标检测和分析方面很有效。然而，要在日常产品中实现应用，必须开发低成本制造方法，同时保持高性能光学功能。为满足这些要求，我们对线栅偏振器的几何结构进行了分析，并设计开发了一种具有纳米三角波形结构的线栅偏振器，该偏振器可使用通用制造设备制造。一旦制备好模具，这种偏振器就可以通过纳米压印和法向角金属沉积或化学镀工艺制造。通过化学镀镍制造的偏振器实现了40%的透过率，这比之前在具有相同周期的矩形结构上使用化学镀镍的研究中所达到的透过率高出约1.4倍。此外，通过法向角铝沉积制造的偏振器在从可见光到近红外的宽波长范围内工作，在550nm波长处实现了24dB的偏振消光比和81%的高透过率。与传统基于矩形结构的线栅偏振器制造中采用的斜角沉积方法相比，使用通用设备通过法向角沉积可以获得高性能偏振器,从而有助于降低成本并提高可制造性
