Terahertz reflective ptychography (Conference Presentation)

As a widely used lensless coherent diffraction imaging approach, ptychography has recently been implemented in Terahertz range. Combining with the unique penetration property of THz radiation, THz ptychography allows inspecting visually opaque samples and retrieving both amplitude and phase information. Here, we demonstrate for the first time to our knowledge, THz ptychography in reflective configuration. Due to the large wavelength (96.5 μm), THz ptychography requires small recording distance. Particular care has been taken in the experimental setup to minimize the recording distance. Extended ptychographic iterative engine (ePIE) is applied to reconstruct quantitatively the amplitude and phase information of the object wavefront. A lateral resolution of 180 μm and a depth resolution of 1.1μm are achieved.