Transport at Nanoscale Interfaces Laboratory

Terahertz ptychography

Valzania, L., Feurer, T., Zolliker, P., & Hack, E.;

Optics Letters, 43(3), 543-546.; 

https://doi.org/10.1364/OL.43.000543

We
https://www.empa.ch/documents/56066/1079682/20180130-valo-thumbnail.jpg/8bf1fe64-4482-4a1b-ac2b-e95d54b99b88?t=1517303249000
realized a phase retrieval technique using terahertz (THz) radiation as an alternative to THz digital holography, named THz ptychography. Ptychography has been used in x-ray imaging as a groundbreaking improvement of conventional coherent diffraction imaging. Here we show that ptychography can be performed at THz frequencies too. We reconstructed an amplitude and a phase object with both simulated and real data. Lateral resolution accounts to <2𝜆, while depth variations as low as 𝜆/30 can be assessed.