Lensless Three-Dimensional Quantitative Phase Imaging Using Phase Retrieval Algorithm

Abstract

Quantitative phase imaging (QPI) techniques are widely used for the label-free examining of transparent biological samples. QPI techniques can be broadly classified into interference-based and interferenceless methods. The interferometric methods which record the complex amplitude are usually bulky with many optical components and use coherent illumination. The interferenceless approaches which need only the intensity distribution and works using phase retrieval algorithms have gained attention as they require lesser resources, cost, space and can work with incoherent illumination. With rapid developments in computational optical techniques and deep learning, QPI has reached new levels of applications. In this tutorial, we discuss one of the basic optical configurations of a lensless QPI technique based on the phase-retrieval algorithm. Simulative studies on QPI of thin, thick, and greyscale phase objects with assistive pseudo-codes and computational codes in Octave is provided. Binary phase samples with positive and negative resist profiles were fabricated using lithography, and a single plane and two plane phase objects were constructed. Light diffracted from a point object is modulated by phase samples and the corresponding intensity patterns are recorded. The phase retrieval approach is applied for 2D and 3D phase reconstructions. Commented codes in Octave for image acquisition and automation using a web camera in an open source operating system are provided.

Spatio‐Spectral‐Temporal Imaging of Fast Transient Phenomena Using a Random Array of Pinholes

“…The aforementioned developments improved the advantages of PSH‐based imaging methods over coherent diffraction imaging methods based on phase retrieval algorithms. [ 24,39 ] In general, coded aperture is an umbrella term encompassing all types of coded apertures including chaotic optical waves, but for 3D imaging chaotic optical waves with a certain degree of chaos are essential. [ 40 ] To reinstate this difference, the imaging system has been identified with chaotic optical waves instead of coded aperture.…”

Roadmap on Digital Holography-Based Quantitative Phase Imaging

“…Conventional interferometry has been widely used for quantifying the above events, which we believe are limited by the information bandwidth and are bulky and difficult to implement. In the coming years, we believe that the current methods will be replaced by single shot, elegant, computational optical methods with higher information bandwidth [88,89].…”

“…New imaging techniques based on multidimensional characterization of events changing in 3D volume, time, and spectrum are emerging and can solve previously encountered obstacles of characterization of micro-volumes via pump-probe interferometric techniques [82,86]. With the recent developments in imaging technologies to observe fast transient events in five dimensions [88] and rapidly converging (<5 iterations) phase retrieval approaches [89] using a single camera shot, we believe that it will be possible to obtain additional information about the rapid events occurring in a small volume in space, without the use of bulky time resolved interferometry.…”

Computing 3D Phase-Type Holograms Based on Deep Learning Method

“…Moreover, the reconstruction results by using the phase-only liquid crystal-based SLMs could have no interference of conjugate image. The iterative methods have significant advantages in phase retrieval [4][5][6]. However, for CGH generation, there is an unavoidable problem with the iterative methods because they require a trade-off between computation time and image quality caused by the iterative process [7][8][9].…”