Single-shot ptychography

Abstract

Ptychography is a particularly powerful coherent diffraction imaging technique. In ptychography, a localized beam that illuminates the object is scanned in a step-wise fashion, resulting in an array of partially overlapping probing spots on the object. The intensity diffraction pattern from each spot is recorded separately. Then, a complex-valued image is computationally constructed from the set of measured diffraction patterns. Ptychography is based on scanning, hence it results with a long overall acquisition time, in the order of a second or more. Also, the scanning limited resolution, vibration stability, drift, and dynamic range weaken the performances of ptychographic microscopes. We propose and analyze single-shot ptychography, where tens or hundreds of quasi-localized, partially overlapping beams illuminate the object simultaneously. Various schemes for single-shot ptychography, in both the transmission and reflection modes, with coherent and partially coherent illumination and for single-shot Fourier ptychography are proposed. Experimentally, we demonstrate single-shot ptychography with a 180 ms exposure time (limited by the CCD minimal acquisition time) using a sub-milliwatt diode laser that simultaneously illuminates the object with 49 partially overlapping beams. Single-shot ptychography, which combines the celebrated power of ptychography with (ultra)fast imaging, will surely open up new opportunities in microscopy.