Spatial light modulator-controlled alignment and spinning of birefringent particles optically trapped in an array.
We demonstrate the use of a phase-only liquid-crystal spatial light modulator (SLM) for polarization-controlled rotation and alignment of an array of optically trapped birefringent particles. A collimated beam incident upon a two-dimensional lenslet array yields multiple foci, scaled to produce optical gradient traps with efficient three-dimensional trapping potentials. The state of polarization of each trapping beam is encoded by the SLM, which acts as a matrix of wave plates with computer-controlled phase retardations. Control of the rotation frequency and alignment direction of the particles is achieved by the transfer of tunable photon spin angular momentum.
Eriksen
René L
RL
Optics and Fluid Dynamics Department, Risø National Laboratory, P.O. Box 49, DK-4000 Roskilde, Denmark.
Rodrigo
Peter J
PJ
Daria
Vincent R
VR
Glückstad
Jesper
J
D001718:Birefringence; D004867:Equipment Design; D007834:Lasers; D007909:Lenses; D008859:Microscopy, Polarization / Q000295:instrumentation; D055095:Optics and Photonics; D010316:Particle Size