Piezoelectric actuator using a LiNbO3 bimorph for an optical switch

The authors describe a ferroelectric actuator that uses an LiNbO ₃ plate with an antipolarity ferroelectric laminar domain (inversion layer). They studied the characteristics of 140° and 165° rotated Y-cut LiNbO₃ bimorph plates and explored the feasibility of using an actuator with the LiNbO₃ plate in an optical switch that switches the optical paths of multimode optical fibers. The actuator fabricated had stoppers on both sides of the plate and a 45-mg load was bonded using soft resin. This mass was used to damp secondary resonance generated by the plate hitting the stopper. The actuator could be switched in 10 ms or less. The authors made a prototype optical switch by placing graded-index fibers on the top of the LiNbO₃ plate to permit optical path switching based on the actuator´s displacement. The optical switch had a switching time of 10 ms or less, with a loss of 0.8 dB or less