Tunable electro-optical lithium niobate phase array for wavefront modulators

We present an adaptive and dynamic hexagonal electro-optic phase array. The proposed device consists of a 2-dimensional hexagonal array of periodically inverted ferroelectric domains, along the z-axis, in lithium niobate crystals. The phase step is achieved via the application of an external electric field, along the z-axis, through transparent electrodes. Thanks to the electro-optic effect the phase step can changed with continuity over all the 0 to 2pi by applying a variable voltage. In this way different patterns can be generated. In fact, one important property of this new proposed configuration of array illuminator is the intrinsic flexibility. Such flexible array could be potentially used in a variety of applications such as optical interconnects, tunable lithographic masks, 2D optical trapping and assembling of particles or wavefront phase modulators. As example, photolitography experiments are performed by means of this optical phase mask with electrooptically tunable phase step. In fact, the collimated beam of an argon laser passes through the phase mask and the near field intensity patterns, at different planes of the Talbot length and for different values of the applied voltage, are used for photolitographic experiments.