Simultaneous optical trapping and imaging in axial plane

Abstract

The exploitation of single objective lens for both trapping and imaging in standard optical trapping system confines the trapping and imaging planes to the focal plane, which hinders the development of optical trapping along axial direction. To break the limitation, we develop an axial-plane optical trapping and imaging setup and demonstrated simultaneous trapping and imaging in axial plane. A modified Gerchberg-Saxton iterative algorithm based on axial-plane Fourier transform is proposed for direct shaping of novel optical traps in axial plane. With the combination of the proposed algorithm and the axial-plane imaging technique, axial-plane holographic optical tweezers is demonstrated and parallel calibration of multiple traps along axial direction is realized. The proposed technique also provides direct visualization of the trapped particles for study on trap performance of various optical fields, including Bessel beams, Airy beams and snake beams. © 2018 SPIE.