Development of active gratings for ultrafast monochromators

Summary form only given. We present the design and characterization of active deformable gratings to be used for the realization of monochromators for extreme-ultraviolet ultrafast pulses [1]. The device consists of a diffractive layer realized by UV lithography that is deposited on the top of a bimorph deformable mirror, whose curvature radius can be varied changing the voltage applied to an underlying piezo-actuator [2]. The samples that have been tested have high optical quality, are robust and compatible with any coating deposition and have only vacuum-compatible materials. We present the characterization of the prototypes in the vacuum ultraviolet and in the visible, showing that the active grating can optimize the beam focusing through its rotation and deformation.