Development of single grating x-ray Talbot interferometer as a feedback loop sensor element of an adaptive x-ray mirror system

The initial result of using a single 2-D checkerboard phase-grating Talbot interferometer as a feed-back loop sensor element of an adaptive x-ray mirror system is reported. The test was performed by measuring the surface profile of a deformable Pt coated Silicon mirror at five different actuation states. The reflected beam was detected at the fractional Talbot distance of a π/2 phase grating. The measured interferograms were de-convolved using the spatial harmonic imaging technique to extract the phase and amplitude of the reflected wavefront. The wavefront was then propagated to the mirror center to retrieve the surface profile of the mirror. The activation of a single actuator was easily detected from the reconstructed surface profile of the mirror. The presented results indicate that the single phase-grating x-ray Talbot interferometer is capable of sensing nano-meter scale profile changes of an adaptive mirror.