Hyperplane lens based on crystalline titanium dioxide

Abstract

The invention provides a hyperplane lens based on crystalline titanium dioxide which can operate efficiently in the visible spectrum. The hyperplane lens includes a planar substrate and a plurality ofnanorods disposed on the planar substrate, the materials of the planar substrate and the plurality of nanorods are crystalline titanium dioxide, the phase value of each nanorod satisfies the following relationship: (please refer to the description), where l is an arbitrary integer, lambda 0 and phi 0 are the preset wavelength and focal length of the hyperplane lens, and (xi, yi) are the coordinates of each nanorod. In addition to the ability of focusing the light to the diffraction limit spot, the hyperplane lens can realize wide-band focusing, and the color difference deviation from the ideal focal spot is only about 10%. Compared with the recent popular P-B hyperplane lens (limiting the incident light to a circularly polarize state), the hyperplane lens can make the incident light insensitive to the polarized state. The hyperplane lens has the characteristics of ultra-thin, compactness and relatively high performance, and can play an important role in realizing miniaturization and lightweight optical systems.

Description

technical field [0001] The invention relates to the field of optical technology, in particular to a hyperplane lens based on crystalline titanium dioxide. Background technique [0002] Traditional lenses are generally formed by cascading precision lenses, which makes the lenses very bulky and expensive, which is not conducive to their application in efficient integrated systems. In recent years, the emergence of hyperplanes, a two-dimensional metamaterial that can arbitrarily control the phase, intensity, and polarization state of beam wavefront arrays, has become a good platform for integrated optical devices, where the phase can be precisely utilized with subwavelength dimensions. At present, many well-integrated optical devices based on hyperplanes, such as hyperplane lenses, axicon lenses, wave plates, and vortex light generation films, have been described a lot. Although there have been a lot of works on hyperplane lenses, most of the previous work focused on qualitati...

AI Technical Summary

Problems solved by technology

Although there have been a lot of works on hyperplane lenses, most of the previous work focused on qualitatively characterizing the focusing effect with several or more than a dozen unit structure antennas, which makes them far from the actual product application.

Moreover, most of the materials used to form hyperplane lenses are based on silicon or metal materials. The working wavelengths of these materials mostly work in the mid-infrared or terahertz bands, and the absorption loss in the visible light band is relatively high. Therefore, the focusing of visible light lenses based on these materials in the past low efficiency

Images