Optical particle manipulation by application-specific densely packed VCSEL arrays

Densely packed arrays of vertical-cavity surface-emitting lasers (VCSELs) are presented, serving as low-cost and small-sized laser sources in optical particle manipulation systems. A novel, self- aligned fabrication process enables both a pitch in the 20 mum range and a selective surface etch for enhanced transverse singlemode emission. Homogeneous array performance and singlemode output powers of up to 3.8 mW are observed. By inserting the arrays into an optical tweezer setup with external optics, multiple optical traps are easily created. Non-mechanical particle translation by switching between individually addressable devices as well as continuous particle deflection in a one-dimensional optical lattice are demonstrated.