基于SiO/薄膜Ag/玻璃结构上的镍亚波长光栅的磁场光学检测。

Optical detection for magnetic field using Ni-subwavelength grating on SiO/thin-film Ag/glass structure.

作者信息

Takashima Yuusuke, Moriiwa Kohei, Haraguchi Masanobu, Naoi Yoshiki

机构信息

Graduate School of Science and Technology, Tokushima University, 2-1 Minami-josanjima, Tokushima, 7708506, Japan.

Graduate School of Advanced Technology and Science, Tokushima University, 2-1 Minami-josanjima, Tokushima, 7708506, Japan.

出版信息

Sci Rep. 2020 Nov 9;10(1):19298. doi: 10.1038/s41598-020-74202-w.

DOI:10.1038/s41598-020-74202-w

PMID:33168843

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC7653930/

Abstract

An optical sensor for magnetic field detection using Ni-subwavelength grating (SWG) on SiO/Ag-thin-film/glass substrates was experimentally developed on the basis of the re-radiation condition of surface-plasmon-polaritons (SPPs) at Ag surfaces. The fabricated sample showed two dips in the reflection spectra associated with SPP excitation, and the optical response exhibited good agreement with that simulated by the finite-difference time-domain method. The reflectivity at one of the dip wavelengths varied minimally with the application of the magnetic field, whereas that at the other dip wavelength significantly decreased owing to the large electric field overlap of SPP with the magnetized Ni-SWG. As a result, a magnetic field on the order of a few mT could be detected with a simple normal-incidence optical system.

摘要

基于银表面表面等离激元极化子（SPP）的再辐射条件，在SiO/Ag薄膜/玻璃衬底上通过实验开发了一种使用镍亚波长光栅（SWG）进行磁场检测的光学传感器。所制备的样品在与SPP激发相关的反射光谱中出现两个凹陷，并且光学响应与有限时域差分法模拟的结果显示出良好的一致性。其中一个凹陷波长处的反射率随磁场施加变化极小，而另一个凹陷波长处的反射率由于SPP与磁化镍SWG的大电场重叠而显著降低。结果，使用简单的正入射光学系统就可以检测到几毫特斯拉量级的磁场。