Shack-Hartmann multiple-beam optical tweezers.

We introduce a new method for generating an array of programmable optical tweezers based on the principle of the Shack-Hartmann wave front sensor. In this approach, a lenslet array divides a laser beam into multiple point sources that are subsequently imaged onto the sample plane of an inverted microscope. This results in a matrix of tightly focused beams used for local confinement and manipulation of micron-sized dielectric particles in an aqueous solution.

Interactive light-driven and parallel manipulation of inhomogeneous particles.

A light-driven micromanipulation system with real-time userfeedback control is used to simultaneously trap colloidal suspensions enabling a unique interactive sorting capability and arbitrary patterning of microscopic particles. The technique is based on a straightforward phase-tointensity conversion generating multiple beam patterns for manipulation of particles in the observation plane of a microscope. Encoding of phase patterns in a spatial light modulator, which is directly controlled by a computer, allows for dynamic reconfiguration of the trapping patterns, where independent control of the position, size, shape and intensity of each beam is possible.