Three dimensional optical manipulation and structural imaging of soft materials by use of laser tweezers and multimodal nonlinear microscopy

TL;DR

This paper presents an integrated system combining holographic optical trapping and multimodal nonlinear microscopy for simultaneous 3D manipulation and structural imaging of soft materials, enabling visualization and control of molecular order and topological defects.

Contribution

The work introduces a novel combined system for 3D optical manipulation and multimodal nonlinear imaging of soft matter, allowing detailed visualization and control of molecular structures and defects.

Findings

Successful simultaneous manipulation and imaging of soft materials.

Visualization of long-range molecular order via nonlinear microscopy.

Control and reconstruction of topological defects in 3D.

Abstract

We develop an integrated system of holographic optical trapping and multimodal nonlinear microscopy and perform simultaneous three-dimensional optical manipulation and non-invasive structural imaging of composite soft-matter systems. We combine different nonlinear microscopy techniques such as coherent anti-Stokes Raman scattering, multi-photon excitation fluorescence and multi-harmonic generation, and use them for visualization of long-range molecular order in soft materials by means of their polarized excitation and detection. The combined system enables us to accomplish both, manipulation in composite soft materials such as colloidal inclusions in liquid crystals as well as imaging of each separate constituents of the composite material in different nonlinear optical modalities. We also demonstrate optical generation and control of topological defects and simultaneous reconstruction of their three-dimensional long-range molecular orientational patterns from the nonlinear optical images.