We are engaged in applying the Generalized Phase Contrast (GPC) method that enables lossless light conversion of spatial phase patterns to highly photon efficient light distributions. The GPC-method can be used in a number of applications requiring parallel light-beam encoding such as in advanced user-controlled optical micro-manipulation, wavefront sensing and generation for common-path interferometry and adaptive optics, optical phase-only encryption and integrated micro-optical implementations. In this work, we 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 3D space and time, hence true 4D. Real-time reconfigurable light patterns with sub-micron accuracy are obtained from a direct map of phase patterns addressed on programmable phase-only spatial light modulator devices. A graphical user interface enables real-time, interactive and arbitrary control over the dynamics and geometry of synthesized light patterns. Experimental demonstrations have shown that GPC-driven micro-manipulation can be used for guided assembly of particles in a plane, control of particle stacking along the beam axis, manipulation of multiple hollow beads and real-time sorting of inhomogeneous mixtures of micro-particles. 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 in the future.

Date Published: 14 March 2005
PDF: 7 pages
Proc. SPIE 5736, Nanomanipulation with Light, (14 March 2005); doi: 10.1117/12.590302

Published in SPIE Proceedings Vol. 5736:
Nanomanipulation with Light
David L. Andrews, Editor(s)