MICROLENS FOCAL LENGTH CONTROLING FOR OPTICAL TWEEZER ARRAYS BY ACOUSTO-OPTIC MODULATION IN GERMANIUM

The microlens arrays created by ultrasonic waves in acousto-optical material Germanium (Ge) is theoretically proposed. The simulated results show the proposed microlens arrays can be used for optical tweezers arrays to trap an assembly micro-beads. Moreover, with the control by changing of the ultrasonic intensity and frequency, the optical tweezers arrays will act as the dynamical one, which can sieve the beads in (X,Y) plane in the embedding fluid. The focal length of microlens in Germanium controling by frequency and intensity of ultrasonic wave is discussed.