New paper accepted to Optics Express

New paper accepted to Optics Express, 2015:

Fast phase processing in off-axis holography using multiplexing with complex encoding and live-cell fluctuation map calculation in real-time

Pinhas Girshovitz and Natan T. Shaked

Abstract: We present efficient algorithms for rapid reconstruction of quantitative phase maps from off-axis digital holograms. The new algorithms are aimed at speeding up the conventional Fourier-based algorithm. By implementing the new algorithms on a standard personal computer, while using only a single-core processing unit, we were able to reconstruct the unwrapped phase maps from one megapixel off-axis holograms at frame rates of up to 45 frames per second (fps). When phase unwrapping is not required, the same algorithms allow frame rates of up to 150 fps for one megapixel off-axis holograms. In addition to obtaining realtime quantitative visualization of the sample, the increased frame rate allows integrating additional calculations as a part of the reconstruction process, providing sample-related information that was not available in real time until now. We use these new capabilities to extract, for the first time to our knowledge, the dynamic fluctuation maps of red blood cells at frame rate of 31 fps for one megapixel holograms.

[PDF, Media 1, Media 2] [Link]

Fast off-axis holographic processing of the dynamic quantitative physical thickness maps of red blood cells. The initial hologram contained 1024×2048 pixels. At the same time of the phase map calculation, we have calculated the dynamic membrane fluctuation map in a window of 1024×256 pixels, shifted across the field of view, as obtained by a FIFO stack of 24 points in time per each pixel. All calculations were performed on a single-core processing unit of a conventional personal computer. White scale bar represents 10 µm upon the sample.