Ptychography as a wavefront sensor for high-numerical aperture extreme ultraviolet lithography: Analysis and limitations

Wavefront aberration measurements are required to test an extreme ultraviolet (EUV) imaging system. For a high-NA EUV imaging system, where conventional wavefront-sensing techniques show limitations, ptychography can be used for this purpose. However, at the wavelength region of EUV (i.e., 13.5 nm), the position accuracy of the scanning mask...

Model-independent noise-robust extension of ptychography

A noise-robust extension of iterative phase retrieval algorithms that does not need to assume a noise model is proposed. It works by adapting the intensity constraints using the reconstructed object. Using a proof-of-principle ptychographic experiment with visible light and a spatial light modulator to create an object, the proposed method is...

Non-iterative phase retrieval by phase modulation through a single parameter

We report on a novel non-iterative phase retrieval method with which the complex-valued transmission function of an object can be retrieved with a non-iterative computation, with a limited number of intensity measurements. The measurements are taken in either real space or Fourier space, and for each measurement the phase in its dual space is...

Combining ptychographical algorithms with the Hybrid Input-Output (HIO) algorithm

In this article we combine the well-known Ptychographical Iterative Engine (PIE) with the Hybrid Input-Output (HIO) algorithm. The important insight is that the HIO feedback function should be kept strictly separate from the reconstructed object, which is done by introducing a separate feedback function per probe position. We have also...