Optical Lattices:Design Based On Optical Field Modulation And Applications In Precision Measurements

Optical lattices are periodical potential wells stemed from multi-beams superposition and interference,which can be divided into one-dimensional,twodimensioanl and three-dimensional patterns based on dimensionality,which also can be categorized as primitive(fundamental)lattices or sparse lattices according to periodicity,which,of course,can be classified by Bravais symmetry.Optical lattices,created by modulation on optical field based on a spatial light modulator,have many features,such as flexibility,diversity,good consistency,rapid changing,more importantly,the ability to change their periods,cell sizes and symmetries almost in real time.In addition,the precision of periods can be traced back to the pixel accuracy of spatial light modulator.In light of the above features,optical lattices have bean playing a pivotal role in many fields,including atom trapping and cooling,atomic clock,photonic crystal nanolithography,microfluidic sorting,super-resolution microscopy and so on.Among of them,lattice light-sheet microscopy emerged in recent two years is an outstanding representative.However,the applications in metrology are rare reported.Based on the advantages of optical lattices,this paper proposes,for the first time,optical lattices topography used in measuring surface morphology.The main work of this paper includes the following points.1)Summarize the optical lattices from origin to development,and from theories to applications.Based above content,this paper elaborates the application and significance of optical lattices in lattice light-sheet microscopy.After that,this paper proposes optical lattice topography to expand its applications in metrology.2)Theoretically derive the design procedures of primitive optical lattices,sparse optical lattices,and composite optical lattices,based on the experimental generation mechanism of optical lattices.Besides,set up experimental light path to verify designs.3)Propose,for the first time,the concept of optical lattice topography,and verify it in both theoretically and experimentally.In theory,based on modeling the maximally symmetric composite square lattice,deduce the mathematic relations between the changes of optical lattices and the undulation of surface.After that,the corresponding phase unwrapping algorithm and morphology reconstruction algorithm are given.In experiement,regarding the deformable mirror calibrated by interferometer as a flexible sample,apply optical lattice topography to reconstruct the morphology of the deformable mirror and campare the experiement results with that of interferometer.During this experiment,the deformable mirror can be programmed to present various degrees of tilting deformations and local convex deformations.4)Set up the lattice light-sheet microscopy and create successfully the lattice-like light sheet.In addition,sweep the light sheet with galvo mirror to create uniformly distributed light sheet under dither mode.This paper presents the measurement principle,general framework,light path configuration and software control strategy of this system.