Fast 1 x 2 and 2 x 2 fiber optic switches with piezoelectric actuation

A novel design of a microoptical fiberoptic 2 x 2 and 1 x 2 switch is presented. The fiber input and output ports are realized with the use of silicon V-grove fiber arrays. The input beams are collimated by a microlens array consisting of two lenslets, separated by the same pitch as the fibers. These two collimated beam which are extremely parallel to each other, are focussed into one spot by a simple plano-convex lens. The focal length of the microlenses and this plano-convex lens determine the magnification of the mode field diameter of the fiber. Switching is performed by using a special two-sided high reflectivity mirror placed in the focal plane of the plano-convex lens, with the use of a high speed piezoelectric actuator. For the microlens array - fiber array mounting process a special setup has been built up, allowing for semi-automatic alignment. The assembly technology for all the single components and modules is described, gluing is used as the main fixing techniques. First prototypes show excellent optical parameters (1.5 dB insertion loss, -70 dB crosstalk) and very short switching time of 0.3 ms.