High-Order Fiber Mode Beam Parameter Optimization for Transport and Rotation of Single Cells.

Zihao Shan,Shunnan Yao,Dun Pi,Enfan Zhang,Feng Lin,Zhen Cai,Wen Cao,Xingkun Wu

doi:10.3390/mi12020226

Abstract

Optical tweezers are becoming increasingly important in biomedical applications for the trapping, propelling, binding, and controlled rotation of biological particles. These capabilities enable applications such as cell surgery, microinjections, organelle extraction and modification, and preimplantation genetic diagnosis. In particular, optical fiber-based tweezers are compact, highly flexible, and can be readily integrated into lab-on-a-chip devices. Taking advantage of the beam structure inherent in high-order modes of propagation in optical fiber, LP11, LP21, and LP31 fiber modes can generate structured radial light fields with two or more concentrations in the cross-section of a beam, forming multiple traps for bioparticles with a single optical fiber. In this paper, we report the dynamic modeling and optimization of single cell manipulation with two to six optical traps formed by a single fiber, generated by either spatial light modulation (SLM) or slanted incidence in laser-fiber coupling. In particular, we focus on beam size optimization for arbitrary target cell sizes to enable trapped transport and controlled rotation of a single cell, using a point matching method (PMM) of the T-matrix to compute trapping forces and rotation torque. Finally, we validated these optimized beam sizes experimentally for the LP21 mode. This work provides a new understanding of optimal optical manipulation using high-order fiber modes at the single-cell level.

Highlights

Published: 23 February 2021Fiber-based optical tweezers (FOT) have recently found a wide range of applications in manipulation of micro- and nanoparticles, as well as biological cells and biomolecules.In contrast to conventional optical tweezers (COT) requiring bulky microscope objectives and high numerical apertures to focus a laser beam, February 2021Fiber-based optical tweezers (FOT), and especially single fiber optical tweezers (SFTs), can be implemented in very low-cost miniaturized systems or even biochips such as optofluidic platforms or catheters [1,2]
In order to achieve complex manipulations such as single cell rotations, essential for medical, genetic, and cellular biological applications such as nuclear transplantations [6,7], embryo microinjections [8,9], and polar body biopsies [10,11,12,13,14], tweezer beams containing two or more field concentrations are often needed. These patterned beams can be generated using specialized multicore fiber [2,15], but more recently techniques taking advantage of the intrinsic structure in high-order fiber propagation modes with multiple lobes of coherent fields have come into the forefront
These types of single-core fiber optical tweezers can utilize conventional optical communication fibers with no specialized components and Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations

Summary

Introduction

Published: 23 February 2021Fiber-based optical tweezers (FOT) have recently found a wide range of applications in manipulation of micro- and nanoparticles, as well as biological cells and biomolecules.In contrast to conventional optical tweezers (COT) requiring bulky microscope objectives and high numerical apertures to focus a laser beam, FOT, and especially single fiber optical tweezers (SFTs), can be implemented in very low-cost miniaturized systems or even biochips such as optofluidic platforms or catheters [1,2]. In order to achieve complex manipulations such as single cell rotations, essential for medical, genetic, and cellular biological applications such as nuclear transplantations [6,7], embryo microinjections [8,9], and polar body biopsies [10,11,12,13,14], tweezer beams containing two or more field concentrations are often needed These patterned beams can be generated using specialized multicore fiber [2,15], but more recently techniques taking advantage of the intrinsic structure in high-order fiber propagation modes with multiple lobes of coherent fields have come into the forefront. These types of single-core fiber optical tweezers can utilize conventional optical communication fibers with no specialized components and Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations

Methods

Results

Conclusion