Optical trapping and manipulation of massive particles based on spatial diffraction of a 45° tilted fiber Bragg grating.

Abstract

In this work, we proposed an optical trapping and manipulation technology based on spatial diffraction of 45° tilted fiber Bragg grating (TFBG). The length of the line-shape-facula of the TFBG diffraction light can be as large as tens of millimeters, which enables the TFBG trapping system control massive dielectric particles. We analyze the light distribution of the spatial diffraction by using the volume current method (VCM) and established a theoretical model to analyze the optical trapping force of TFBG based on the ray tracing method (RTM). Then, we designed several optical trapping schemes, with two-, three- and four-TFBGs respectively. Numeral simulation indicates that only the scheme with axisymmetric layout of TFBGs can achieve stable particle trapping. We comprehensively analyze the trapping force distribution of four- TFBG scheme with different influence factors. In addition, the rotation manipulation based on the two- and four- TFBGs schemes are also demonstrated. The proposed optical trapping technology open a new route for massive particles trapping and manipulation.