Tuning of near-field optical properties based on magneto-tip array super-surfaces

A method of light wave modulation on a magnetic nano-tip hypersurface was investigated within the wavelength range of 3-14 μm, and a hypersurface was constructed on a silicon wafer using magnetic nano-film to perform light control using the magnetization of the magnetic nano-tip to achieve the desired light absorption. Through the magnetic nanotip hypersurface, the incident light waves hypersurface can be highly confined in the arrayed magnetic nanotip to achieve near-field light enhancement and light focusing, and significantly reduce the infrared reflectivity to achieve efficient absorption of infrared light waves. The infrared reflectivity of the structured surface shows a tunable variation by adjusting the structural parameters of the magnetic nano-tip super-surface. The experiments show that the silicon-based magnetic film nano-tip array achieves stronger nanofocusing and higher absorption rate than the conventional nano-tip array based on metal film.