On the use of deep learning for phase recovery

Phase recovery (PR) refers to calculating the phase of the light field from its intensity measurements. As exemplified from quantitative phase imaging and coherent diffraction imaging to adaptive optics, PR is essential for reconstructing the refractive index distribution or topography of an object and correcting the aberration of an imaging system. In recent years, deep learning (DL), often implemented through deep neural networks, has provided unprecedented support for computational imaging, leading to more efficient solutions for various PR problems. In this review, we first briefly introduce conventional methods for PR. Then, we review how DL provides support for PR from the following three stages, namely, pre-processing, in-processing, and post-processing. We also review how DL is used in phase image processing. Finally, we summarize the work in DL for PR and outlook on how to better use DL to improve the reliability and efficiency in PR. Furthermore, we present a live-updating resource (https://github.com/kqwang/phase-recovery) for readers to learn more about PR.Comment: 82 pages, 32 figure

Real-time phase measurement of optical vortex via digital holography

Real-time phase measurement is of great value to study the evolution of optical vortex. However, it cannot be recorded in real time due to the limitation of the exposure time of the recording device in the experiment. Therefore, based on the temporal and spatial evolution correlation of the optical phase, a real-time phase measurement method of optical vortex generated by an acoustically induced fiber grating is proposed based on digital holographic reconstruction algorithm. First, a series of holograms are continuously recorded using a low frame rate CCD. Then, the evolution of optical vortex over time is translated into changes in transmission distance. Furthermore, the unrecorded vortex phase distributions are calculated using diffraction theory. By serializing these phase maps over time, the propagation and evolution of spiral phase structure of the vortex beam can be demonstrated in real time

Supplementary document for Label-free and dynamic monitoring of cell evolutions using wavelength-multiplexing surface plasmon resonance holographic microscopy - 6373783.pdf

Supplemental documen

Supplementary document for Label-free and dynamic monitoring of cell evolutions using wavelength-multiplexing surface plasmon resonance holographic microscopy - 6346919.pdf

Supplemental Documen

Quantification of SIF.

<p>(<b>A</b>).The UV-visible spectrum of soy isoflavone. (<b>B</b>).The standard curve between the absorbance and SIF concentration. Three different batches microspheres were calculated as the formula described in methods. Data are expressed as the mean ± SD. </p

Determination <i>of</i><i>In</i><i>Vitro</i> Release (R %).

<p>Six samples of different groups of SIF/CHI microspheres were released in different simulation liquids, at 1h, 2h, 4h, 8h, 12h, and 24h to observe the collapse state in each group. </p

Morphology Characterization of SIF/CHI Microspheres.

<p>(<b>A</b>-<b>C</b>). The surface morphology of microspheres prepared from optimized (A) or unoptimized (B) formulation was investigated by stereo-microscope and by fluoroscopy (C) using FITC-labeled chi-tosan. (<b>D</b>). The diameter distribution curve of SIF/CHI microspheres. </p

Morris Water Maze Test.

<p>All mice (n=8 per group) were trained in a circular pool (100 cm in diameter) located in a lit room with visual cues. An escape platform (9 cm in diameter) was submerged 2.0 cm below the surface of the pool water, which was maintained at 23 ± 2°C, and mixed with milk powder to obscure the platform. The location of the platform remained in the center of northwest quadrant throughout the 4-day training period. Then the mice were released into the water facing the wall of the pool, in turn of north, south, east and west for each trial. (<b>A</b>). Latencies to escape from the water maze (finding the submerged escape platform) were collected in the place navigation test. (<b>B</b>).The spatial probe trial was made by removing the platform and allowing each mouse to swim freely for 60s inside the pool. (<b>C</b>).The time of swimming for each mouse spent in the target quadrant (where the platform was removed) and the number of times for each mouse crossed over the target quadrant were recorded with a computerized video system. All values are denoted as the mean ±SD from at least three independent experiments. Bars with different letters differ significantly from each other (P< 0.05). Vehicle: The vehicle control group mice were given daily subcutaneous injection of saline (0.9% NaCl) and 1ml saline (0.9% NaCl) without isoflavone orally for 30 days. Model: The model group mice were received daily subcutaneous injection of D-gal for 30 days and were given 1ml saline (0.9% NaCl) without SIF orally for 30 days. NSR: The NSR group mice were received the same mass of D-gal and daily SIF commercial capsules containing 75 mg/kg isoflavone in saline (0.9% NaCl) by oral gavage for 30 days. SR: The SR group mice were given the same mass of SIF/CHI microspheres packaged in empty capsules as the NSR group. </p

Determination <i>of In Vitro</i> Release (R %) of SIF/CHI Microspheres containing different chitosan concentration.

<p>Determination <i>of In Vitro</i> Release (R %) of SIF/CHI Microspheres containing different chitosan concentration.</p