Fabrication of Chiral 3D Microstructure Using Tightly Focused Multiramp Helico-Conical Optical Beams

Abstract

Beams with optical vortices are widely used in various fields, including optical communication, optical manipulation and trapping, and, especially in recent years, in the processing of nanoscale structures. However, circular vortex beams are difficult to use for the processing of chiral micro and nanostructures. This paper introduces a multiramp helical–conical beam that can produce a three-dimensional spiral light field in a tightly focused system. Using this spiral light beam and the two-photon direct writing technique, micro–nano structures with chiral characteristics in space can be directly written under a single exposure. The fabrication efficiency is more than 20 times higher than the conventional point-by-point writing strategy. The tightly focused properties of the light field were utilized to analyze the field-dependent properties of the micro–nano structure, such as the number of multiramp mixed screw-edge dislocations. Our results enrich the means of two-photon polymerization technology and provide a simple and stable way for the micromachining of chiral microstructures, which may have a wide range of applications in optical tweezers, optical communications, and metasurfaces.

Production of Lipid Constructs by Design via Three-Dimensional Nanoprinting

“…Organizational chirality has gained interest and attention from the fields of chemistry and bioengineering [ 54 , 55 , 56 , 57 , 58 ]. The current means to produce most organizational chiral structures relies on self-assembly [ 59 , 60 , 61 ] that produces chiral domains with broad size distribution, and the entire surface contains a racemic mixture of chiral domains [ 62 , 63 ].…”

Multiparameter encrypted orbital angular momentum multiplexed holography based on multiramp helicoconical beams

“…The phase function of the MHC beams is written as 28 E(x,y)=exp[iα(x2+y2r0−K)(θ−2πnm)],where (x,y) represents the Cartesian coordinates in the holographic plane, α is the TC of the MHC beams, and θ=tan−1(y/x) is the azimuthal angle. m represents the number of multiramp mixed screw-edge dislocations, which is an integer.…”

“…[25][26][27] Note that the HCBs have the additional conical phase modulation compared to the conventional OAM beam, which can provide a new way to boost information capacity. In addition, the multiramp helical-conical (MHC) beam was proposed by Wen et al 28 and its focusing properties were investigated. However, to the best of our knowledge, the MHC beams have not been implemented to enhance the holographic information capacity.…”

Multi-Spiral Laser Patterning of Azopolymer Thin Films for Generation of Orbital Angular Momentum Light

“…Two-photon direct laser writing based on the use of superimposed OV beams and Gaussian beams was used for the fabrication of three-dimensional chiral microstructures with the desired number of lobes whose directions are determined by the sign of the TC [ 13 ]. In addition, specially designed multi-ramp helical conical beams have also been used for the formation of chiral multi-lobe microstructures through a two-photon polymerization effect [ 14 ]. However, all these techniques require multiple processing steps.…”