Metrology of thin adaptive optics for X-ray beamlines

The generational advances in synchrotron radiation sources have historically been bottlenecked by the optics used to focus and manipulate X-ray beamlines. Such optics have strict metrology requirements while needing to be versatile in their abundance of applications. To meet these requirements, thin adaptive optics (TAOs) have been developed to correct optical surface error and perform source wavefront shaping. These TAOs consist of a series of thin-film piezoelectric actuators deposited on a mirror substrate that induce spatially localized figure deformations. In this work, the fabrication and actuator performance of two TAO mirror segments are reported. These ∼ 0.5 mm thick optics have addressable actuators whose responses were measured using Fizeau interferometry. The individual actuator responses of the two TAOs induced a figure change peak-to-valley (PV) of 183 nm and 63 nm on average. Finally, the TAOs were used to measure the deflection of an optical laser under operation of their actuators. These laser deflections were shown to be repeatable under a phase-shifted measured period. The metrology characterization described in this work shows a promising future for TAO development in realizing figure correction and wavefront shaping in X-ray beamlines.