Holographic optical tweezers with real-time hologram calculation using a phase-only modulating LCOS-based SLM at 1064 nm

Abstract

We present a method that enables the generation of arbitrary positioned dual-beam traps without additional hardware in a single-beam holographic optical tweezers setup. By this approach stable trapping at low numerical aperture and long working distance is realized with an inverse standard research microscope. Simulations and first experimental results are presented. Additionally we present first steps towards using the method to realize a holographic 4π-microscope. We will also give a detailed analysis of the phase-modulating properties and especially the spatial-frequency dependent diffraction efficiency of holograms reconstructed with the phase-only LCOS spatial light modulator used in our system. Finally, accelerated hologram optimization based on the iterative Fourier transform algorithm is done using the graphics processing unit of a consumer graphics board.