Simultaneous 3D visualization and position tracking of optically trapped particles using optical diffraction tomography

Precise tracking of three-dimensional (3D) positions of objects, often associated with optical tweezers, is important for the study of biophysics and cell biology. Although various approaches for 3D particle tracking have been proposed, most are limited in resolution and axial localization for objects of complex geometry. Holographic tomography systems circumvent these problems and offer improved capability in localization of objects over current methods. Here, we present a combined system employing optical diffraction tomography and holographic optical tweezers capable of simultaneous 3D visualization of the shapes and tracking positions of trapped microscopic samples. We demonstrated the capability of the present combined system using optically trapped silica beads and biological cells. (C) 2015 Optical Society of America