Above and beyond: Holographic tracking of axial displacements in holographic optical tweezers

Abstract

How far a particle moves along the optical axis in a holographic optical trap is not simply dictated by the programmed motion of the trap, but rather depends on an interplay of the trap's changing shape and the particle's material properties. For the particular case of colloidal spheres in optical tweezers, holographic video microscopy reveals that trapped particles tend to move farther along the axial direction than the traps that are moving them and that different kinds of particles move by different amounts. These surprising and sizeable variations in axial placement can be explained by a dipole-order theory for optical forces. Their discovery highlights the need for real-time feedback to achieve precise control of colloidal assemblies in three dimensions and demonstrates that holographic microscopy can meet that need.

arXiv comment7 pages, 3 figures

References in corpus (5)

• Characterizing and tracking single colloidal particles with video holographic microscopy
• Optimized holographic optical traps
• Holographic assembly of quasicrystalline photonic heterostructures
• Machine-learning techniques for fast and accurate feature localization in holograms of colloidal particles
• Real-time optical micro-manipulation using optimized holograms generated on the GPU

Cited by in corpus (4)

• CATCH: Characterizing and Tracking Colloids Holographically using deep neural networks
• Large depth-of-field tracking of colloidal spheres in holographic microscopy by modeling the objective lens
• Dexterous holographic trapping of dark-seeking particles with Zernike holograms
• Multi-angle holographic characterization of individual fractal aggregates