Fig. 2.

Optical trapping characterization. a) Trapping accuracy: histogram of positions for a single trapped particle at 780 mW, inset shows the particle positions within the trap during the measurment. b) Trapping precision: histograms of lateral inter-particle distance for different hologram realizations and different laser powers. c) Trapping accuracy: standard deviation of particle position within a trap as function of power at the trap. d) Position calibration: Confocal measurement of relative Z position in microns verses the requested Z position in SLM pixels. Heights are measured relative to the focal plane of the undiffracted laser light. A different dependence is observed below and above the focal plane of the inverted objective lens, below the focal plane axial position changes as 12 nm/pixel and above it as 7 nm/pixel.