Achromatic Dielectric Metasurface with Linear Phase Gradient in the Terahertz Domain

Abstract

many broadband scenarios. Taking the commonly used beam splitter [23,24] as an example, the reported terahertz circularpolarization beam splitter, [25] all dielectric splitter with variable split ratio, [26] terahertz beam splitter based on I-shape metasurface [27] and optically controlled dynamic splitter, [28] though work in broadband, produce significantly different steering angles in different frequencies resulting from chromatic aberration. Luckily, researches on achromatic metasurfaces in visible and infrared light have made a big progress in recent years, realizing the phase control as well as the dispersion engineering. Several types of achromatic metalens [29-36] have been demonstrated in visible and infrared light by engineering the dispersion and the phase of the unit cells simultaneously to meet the multilevel condi

Active Terahertz Beam Steering Based on Mechanical Deformation of Liquid Crystal Elastomer Metasurface

“…Besides beam steering and frequency shifting, the LCE metasurface grating can be developed as novel active beam splitter as pointed in our previous researches 36, 37 . We placed two C-ring gratings mentioned above on the same LCE substrate, and made the phase gradients of the two gratings mirror-symmetrical.…”

“…4e. As discussed by M. Wei 36 and R. Jia 37 , the splitting ratio can be easily controlled by translating the incident beam thus re-dividing the area on each grating. More importantly, the output angles of the two split beams can be manipulated by adding linefocused infrared pump on the seam.…”

Loss‐induced phase transition in mid‐infrared plasmonic metamaterials for ultrasensitive vibrational spectroscopy

“…The possible optimization method is utilizing all‐dielectric materials to form a photonic crystal slab 61–63 . It works due to its features in reducing the dissipative loss and strong heating in the metals 64–66 . However, when compared with metal metamaterials, all‐dielectric devices suffer from the poor affinity of immobilizing some molecules, which is unfavorable for the surface functionalization in biomolecule sensing.…”

Broadband mid-infrared metalens with polarization-controlled at-will chromatic dispersion

“…[13][14][15][16][17] As a type of two-dimensional metamaterial composed of planar nanostructures on a subwavelength scale, the metasurface has broad prospects for use in the miniaturization, integration, and diversification of optical devices. Metasurfaces have been used widely in the design of various functional optical devices, including optical focusing and deflection elements [18][19][20][21] and polarization conversion and modulation devices, [22][23][24] and in the generation of micro/nanolaser sources. [25][26][27] Through adjustment of their geometrical parameters and structural arrangements, metasurfaces are also capable of producing an effective refractive index and dispersion, which makes them promising candidate materials for the design of dispersion-tailored optical devices.…”