Device for moving a nonlinear crystal or a saturable absorber in two dimensions and method for determining the incremental step of the moving device

The device (1) according to the invention for moving a nonlinear crystal (2) or a saturable absorber in two dimensions comprises: a first and a second piezo positioning unit (3, 4), each with paths of movement that are linear and arranged orthogonally in relation to one another, each of which units has a carriage (8, 10) that can be moved with respect to a carrier (7, 9) step by step along the path of movement between a first end position and a second end position by means of a piezo drive (7a, 9a), wherein the nonlinear crystal (2) or the saturable absorber can be fastened to the carriage (8) of the first piezo positioning unit (3) and the carrier (7) of the first piezo positioning unit (3) is fastened to the carriage (10) of the second piezo positioning unit (4), stops (12, 13, 14, 15) for the carriages (8, 10), respectively defining the end positions, an end position detection for detecting the carriages (8, 10) in the respective end positions thereof, and a counting device (18, 19) for counting the steps