Generation Of Optical Potential Well Based On Metalens And Its Application In Optical Trapping Of Cold Molecules

The miniaturization of ultra-cold atom experimental equipment has always been limited by the size of traditional optical components.In recent years,with the continuous development of optoelectronic technology,electromagnetic control theory and semiconductor device manufacturing process have developed rapidly.This trend makes more and more integrated micro optical devices be designed and manufactured.Metamaterials are ultra-thin planar optical materials that are arranged by subwavelength height units,which can achieve flexible control of electromagnetic wave polarization and phase.Therefore,it provides new ideas for the design of atomic chips.Some atoms based on metasurfaces chips are gradually being proposed.This paper mainly uses metasurfaces to design two atomic chips that can be used for the trapping of atoms and molecules.The main research contents and results are as follows:(1)Propose a new type of super-surface structure,that is,a super-lens composed of silicon-structured grating units with different duty ratios,which can form a focusing halo on the focal plane.The periodic cells of Si micropillars were constructed on the Si O2 substrate,and the cell structure library which can cover the phase adjustment of0-2π range while maintaining high transmittance was selected by scanning different heights,different periods,and different duty ratios.Arranging the microstructure units according to the focusing formula realizes a metasurface lens capable of forming a focusing halo.The maximum relative intensity of the halo can reach 55.At the same time,the focusing effect of different wavelengths and the focusing effect of hyper lenses with different numerical apertures are studied.Finally,an optical storage ring of Mg F molecules is constructed using the focusing halo produced by the hyperlens,and the optical potential and dipole force of the Mg F molecules in the optical field of the focusing halo are calculated,and the van der Waals force of the metasurface interaction is calculated.The Monte-Carlo simulation method was used to study the dynamics of the Mg F molecules in the storage ring.(2)A solution is proposed to change the position between the phase plate and the hyperlens to realize the movable optical double potential well.The specific arrangement of the lens is designed in one dimension.When the center positions of the two hyper lenses overlap,two focal points can be generated.When their relative positions change,the two optical traps gradually overlap into one optical trap,which can be used for two Combinations of two cold molecular clusters.