Device and method for iterative phase recovery based on pixel super-resolved on-chip holography

A method for lens-free imaging of a pathology sample or objects within the sample comprising:

• a) illuminating a sample located a distance z1 away from a light source;
• b) obtaining a first plurality of images of the sample with an image sensor disposed a distance z2 away from the sample, wherein z1>>z2, wherein the plurality of images are obtained by changing the relative position of the light source, image sensor, or sample in lateral shifts;
• c) adjusting the distance z2;
• d) obtaining an additional plurality of images of the sample at the adjusted distance z2, wherein the additional plurality of images at the adjusted distance z2 are obtained by changing the relative position of the light source, image sensor, or sample in lateral shifts;
• e) repeating operations c) and d) a plurality of times;
• f) generating a high-resolution pixel super-resolved hologram at each distance z2 from the first plurality of images and the additional plurality of images at the adjusted distance z2;
• g) recovering lost phase information of the high-resolution pixel super-resolved hologram at a given z2 distance comprising:
• 1) analytically computing an initial phase estimate at the given distance z2 based on first and second measurements of the high-resolution pixel super-resolved hologram(s);
• 2) updating the phase estimate from (1) using propagation of an estimate of a complex optical wave at the given distance z2 to a modified or adjusted z2 distance, which generates new amplitude and phase information for the propagated complex wave;
• 3) applying 3D transformation matrices to the propagated complex wave to correct for relative tilt in the z direction between the sample and the image sensor, wherein the application of the 3D transformation matrices generates a tilted guess, the tilted guess being registered to a measured hologram and averaging the tilted guess amplitude with a measured amplitude to generate updated amplitude followed by rotation back to a plane parallel to the image sensor;
• 4) wherein at the modified or adjusted z2 distance, the updated amplitude of the super-resolved hologram replaces the currently computed amplitude information of the propagated complex wave from (2) and the new phase information is retained for next iterations;
• 5) propagating the complex estimated wave to reach a further modified or adjusted z2 distance;
• 6) repeating steps 3) through 5) among all or a sub-set of measured planes corresponding to different z2 distances as a loop until convergence is achieved;
• and
• h) outputting a phase-recovered complex field at an object plane based on the recovered lost phase information obtained in g) for one or more z2 planes.