A new magneto-optical phenomenon enhanced by Au nanoparticles on 3D Ni sub-microstructures

Abstract

We constructed a bio-structured surface-plasmonic/magneto-optic composite of ferromagnet metal Ni and noble metal Au. It was found that Ni Morpho menelaus (Mm) butterfly wings (BWs) with a natural photonic crystal structure have an apparent enhancement of light reflection under a 0.3 T magnetic field. Additional introduction of discrete Au particles helps further increase this magnetism-induced response. Compared with Mm-Ni-BWs, Mm-Ni–Au30-BWs’ reflectance increases 5.3 times at 1944 nm. This investigation helps reveal and understand the effects of new micro-nanostructures on surface plasmon/magneto-optic coupling, benefiting future applications of biology sensors, chemical sensors, photonic chips, electrical communication systems, etc.