A Polyvinylidene fluoride (PVDF) based bimorph actuator for high speed laser beam manipulation

High-speed laser manipulation is a key technology in applications such as fast optical switches for coupling light into optical fibres, 2D beam steering for optical scanners, laser printers or 2D sensors. A novel design of a Polyvinylidene Fluoride (PVDF) bimorph actuator is proposed in this work as high speed switching element in the kHz range. The actuator of several cm length and 200 microns thickness takes advantage of the structural and electromechanical capabilities of the PVDF. A 0.164 g compact mirror is placed at the tip of the PVDF bimorph actuator allowing scanning of the beam in two directions. Tests made by an autocollimator have been performed in order to characterize the precision, repeatability and also the long term stability at low frequencies. To complete this characterization, a photodiode was used to measure the response of the mirror at high frequencies up to 3 kHz. Results of the FE element confirm the trends observed in the experimental setup. Experimental results indicate that the PVDF actuator responds conveniently to manipulate the laser beam at kHz frequency. In addition, due to the intrinsic properties of the PVDF, the system is compact and light-weight. This is of advantage in several domains such as e. g. aerospace or micro-engineering.