Ultra-high-speed non-interferometric quantitative phase and multi-plane imaging

The existing non-interferometric phase imaging methods are unable to retrieve quantitative phase up to microsecond temporal resolution due to the lack of a suitable parallel recording strategy. Therefore, we propose an ultra-high-speed non-interferometric method for phase and multi-plane imaging using partially coherent light sources. The method uses space division multiplexing to record two or more intensity images in parallel. Due to its ability to acquire images at desired distances, high-speed non-interferometric quantitative phase retrieval can be performed. Furthermore, due to its phase retrieval capability, numerical focusing can be achieved, allowing multiple axial plane images to be obtained from parallelly recorded images. The applicability of the proposed method is confirmed by imaging high-speed gas flow, where both the initial stage and the evolution of cavity formation can be visualized, as well as by imaging electric discharge, where the blocking of light by afterglow plasma can be observed. The developed imaging method can be applied to study phenomena with a wide range of speeds, from static to very fast, in various fields such as physics and life sciences, without the need for coherent light illumination.