Metrology of a Focusing Capillary Using Optical Ptychography

Abstract

The focusing property of an ellipsoidal monocapillary has been characterized using the ptychography method with a 405 nm laser beam. The recovered wavefront gives a 12.5×10.4μm2 focus. The reconstructed phase profile of the focused beam can be used to estimate the height error of the capillary surface. The obtained height error shows a Gaussian distribution with a standard deviation of 1.3 μm. This approach can be used as a quantitative tool for evaluating the inner functional surfaces of reflective optics, complementary to conventional metrology methods.

Special Issue “EUV and X-ray Wavefront Sensing”

“…In the seventh contribution [ 7 ], the wavefront is analyzed to perform otherwise very challenging, if not impossible, metrology on capillary optics. The Special Issue closes with an article dedicated to small-spot optimization, in the presence of a relatively large numerical aperture [ 8 ].…”