Compact Three-Axis Actuator for Positioning a Polymer Microlens in an Optical Pickup

We describe a microelectromechanical systems-based actuator for three-dimensional (3D) positioning of a polymer microlens implemented using silicon-on-glass technology. The actuator combines comb drives for lateral tracking with electrostatic parallel plates for out-of-plane focusing as well as tilting of a polymer microlens, yielding fully 3D actuation. The complete actuator is fabricated using wafer bonding of silicon and pyrex wafers; the lens is integrated using polymer dispensing techniques. The 3 DOF positioning of the lens for focusing, tracking, and tilting are experimentally characterized, furthermore, the layout and symmetry would allow 4 DOF movement, demonstrating how this actuation system combined with an integrated lens may be particularly useful for new generations of optical pickups.