Research On Long-wave Infrared Achromatic Metasurface Lenses

Since 1800 German scientist Herschel discovered the exsistence of infrared light,the infrared devices have been widely used in various fields such as infrared remote control,infrared telemetry,infrared imaging and infrared co mmunication.However,traditional lenses are still difficult to get rid of the disadvantages of bulkiness and complexity while infrared technology has developed very mature.In contrast,the metalens has smaller size,higher freedom of regulation and easier miniaturization and integration.The appearence of metalens innovates the optical field regulation theory,promotes the miniaturization of metasurface optical elements to replace traditional optical elements,and promotes the development of micro nano photonics.8-12 μm is not only an important atmospheric window,but also an important band of h μman radiation,which has special significance in the field of infrared imaging.This article will focus on 8-12 μm long wave infrared region,through the wavefront control ability of metalens,with the advantage of its global optical field control,to achieve 8-12 μm infrared band focusing,fabricate a metalens with high efficiency and practical application value.The main contents of this paper are as follows:1.According to the principles of waveguide transmission and Snell’s law,the efficient metalenses’ unit structure is designed,and the effects of different structural parameters on the performance are studied.Finally,based on pure silicon material,large-size metalenses with focal wavelength of 8,9,10,11 and 12 μm are designed and manufactured;2.According to the broadband achromatic principle,select the appropriate metalens unit,and design 9.3-10.4 μm broadband focused achromatic metalens.