Fast three-dimensional laser scanning scheme using acousto-optic deflectors.

A scheme for fast 3-D laser scanning using acousto-optic deflectors is proposed and demonstrated. By employing counterpropagating acoustic waves that are both chirped and offset in their frequencies, we show that it is possible to simultaneously scan both axially and laterally with frame rates on the order of tens of kilohertz. This scheme was specifically designed for application with multiphoton imaging, particularly of neurons, where it will enable the concurrent monitoring of physiological signals at multiple locations within a microscopic 3-D volume (350 x 350 x 200 microm). When used for this purpose, we demonstrate how this scheme would also inherently compensate for spatial dispersion when ultrafast laser pulses are used in acousto-optic multiphoton microscopy.