New paper in Optics Letters, Vol. 39, No. 8, 2262-2265, 2014:

Pinhas Girshovitz and Natan T. Shaked

Abstract: We present a new approach for obtaining significant speedup in the digital processing of extracting unwrapped phase profiles from off-axis digital holograms. The new technique digitally multiplexes two orthogonal off-axis holograms, where the digital reconstruction, including spatial filtering and two-dimensional phase unwrapping on decreased number of pixels, can be performed on both holograms together, without redundant operations. Using this technique, we were able to reconstruct, for the first time to our knowledge, off-axis holograms with 1 megapixel in more than 30 frames per second using a standard single-core personal computer on a Matlab platform, without using a graphic processing-unit programming or parallel computing. This new technique is important for real-time quantitative visualization and measurements of highly dynamic samples, and is applicable for a wide range of applications, including rapid biological cell imaging and real-time nondestructive testing. After comparing the speedups obtained by the new technique for holograms of various sizes, we present experimental results of real-time quantitative phase visualization of cells flowing rapidly through a micro-channel.

Quantitative imaging of fast flow of blood cells through a micro-channel, processed in video-rate using the new hologram-multiplexing algorithm. Selected for image of the week of the Optical Society of America, April 14, 2014.