Optical fibers with patterned ZnO/electrode coatings for flexural actuators

A fiber-based flexural actuator was developed using a patterned piezoelectric ZnO/electrode fiber coating on a standard telecommunications optical fiber. The actuator was composed of a concentric inner Cr/Au electrode, a thick sputtered ZnO coating, and an outer Cr/Au electrode. Using standard photolithography, 30-mu m wide gaps in one of the electrodes were patterned along 2-cm lengths parallel with the fiber axis. This device can be driven in a bimorph mode. It was demonstrated that a split electrode actuator could be excited into electromechanical resonance to produce useful displacements at the end of the fiber. Such flexural fiber actuators could be used in scanning near field optical microscopes for fiber tip height adjustment. In addition, the actuator design can be extended to manufacture two-axis integrated fiber alignment devices. (C) 1999 Elsevier Science S.A. All rights reserved.