Ptychographic Synthetic Aperture Imaging with Intensity-Only Measurements

Ptychography has emerged as a transformative coherent diffraction imaging technique for both fundamental and applied sciences. Here we discuss a coded ptychography technique that achieves an imaging throughput order of magnitude greater than conventional microscopy approaches. In this platform, we translate the samples across the disorder-engineered surfaces for lensless diffraction data acquisition. The engineered surface can be made by smearing a monolayer of blood on top of the image sensor. The entire system can be built using a modified Blu-ray player, where the 405 nm laser from the optical pickup head can be used as a coherent light source for sample illumination. By tracking the phase wraps of the recovered images, we report the direct observation of bacterial growth in a 1-s interval at a 120 mm
²
area, with a phase sensitivity like that obtained from interferometric measurements. We also characterize cell growth via longitudinal dry mass measurement and perform rapid bacterial detection at low concentrations. The combination of high phase sensitivity, high spatiotemporal resolution, and ultra-large field of view is unique among existing microscopy techniques. We will also discuss the several extensions of the coded ptychography technique, including synthetic aperture ptychography, polarimetric coded ptychography, and depth-multiplexed ptychographic microscopy, thereby expanding its applicability in different fields.