Assembly of 3-dimensional structures using programmable holographic optical tweezers (CAT#: STEM-MB-1306-WXH)

Introduction

Optical tweezers are used for manipulating both single and multiple, micron-sized, particles suspended in solution. Various types of particles can be trapped including transparent silica or polymer spheres, metallic particles and biological specimens. Recent advances in spatial light modulators (SLMs) enable a single laser beam to be split into many beams, enabling the simultaneous trapping of many objects. Such experimental arrangements are termed holographic optical tweezers (HOTs). The SLM is usually positioned in the Fourier-plane with respect to the sample such that angular deflection of the beam at the SLM gives a lateral translation of the trap, and a change in the wavefront curvature gives an axial shift of the trap. The spatial resolution of the SLM, and the aberrations within the system, limit the maximum displacements to a few 10’s µm.