Miniaturized 2D Scanning Microscopy with a Single 1D Actuation for Multi-Beam Optical Coherence Tomography

Abstract: Miniaturized optical imaging systems typically utilize 2-dimensional (2D) actuators to acquire images over a 2D field of view (FOV). Piezoelectric tubes are most compact, but usually produce sub-millimeter FOVs and are difficult to fabricate at scale, leading to high costs. Planar piezoelectric bending actuators (benders) are capable of much larger actuations and are substantially lower cost, but inadequate for 2D steering. We presented a multi-beam fiber scanning platform that generated multi-millimeter 2D scans with a 1D actuator by maximizing the mechanical coupling effect in its orthogonal axis. We further expanded the FOV by demonstrating mosaiced fields driven with spiral and cycloid trajectories, where three optical fibers were optimized to resonate with identical paths in synchronicity. Leveraging optical coherence tomography with a long coherence length laser, we acquired depth-multiplexed images of biological samples at 12.6 um resolution. This multi-fold improvement in scanning coverage and cost-effectiveness promises to accelerate the advent of piezoelectric optomechanics in compact devices such as endoscopes and headsets, and miniaturized microscopes at point-of-care.