The Generalized Phase Contrast (GPC) method enables conversion of spatial phase-only modulation to highly photon efficient light distributions using a non-holographic approach. GPC can be applied in a number of applications requiring parallel light-beam encoding such as in advanced user-controlled optical micro-manipulation, wavefront sensing and generation, adaptive optics, optical phase-only encryption and for integrated micro-optical implementations. In this presentation, I will outline the concept for a complete GPC-platform for advanced and user-interactive manipulation of fluid-borne colloidal structures with state-of-the-art controllability and versatility in time and space. Real-time reconfigurable light patterns in 3D-space with sub-micron accuracy are obtained from a direct map of phase patterns addressed on programmable phase-only spatial light modulator devices. A graphical userinterface enables real-time, interactive and arbitrary control over the dynamics and geometry of synthesized light patterns. Experimental demonstrations have shown that GPC-driven micromanipulation can be used for fully user-guided assembly of particles in a plane, control of particle stacking along the beam axis, manipulation of multiple hollow beads, real-time sorting of inhomogeneous mixtures of micro-particles and the organization of living cells into colloidal structures. These experiments illustrate that GPC-driven micro-manipulation can be utilized not only for the improved synthesis of functional microstructures but also for their non-contact and parallel actuation crucial for sophisticated micro-fluidic based lab-on-a-chip demonstrations.

Contact: Wolfgang Losert