Smart Imaging Laboratory @ UConn

At the Smart Imaging Lab, we develop novel imaging and sensing tools to tackle complex measurement challenges in biology, medicine, and metrology. Our research interests include biomedical instrumentation, computational imaging, ptychography, microscopy, endoscopy, and chip-scale imaging solutions. Major techniques under development in the lab include super-resolution ptychographic endoscopy, coded ptychographic microscopy, ptychographic non-line-of-sight imaging, Fourier ptychography, compact and high-throughput whole slide imaging platforms, ptychographic flow cytometry, non-interferometric synthetic aperture imaging, and other novel imaging techniques.

We are hiring; motivated students and researchers are encouraged to contact Prof. Guoan Zheng.

Featured Publications

"Ptycho-endoscopy on a lensless ultrathin fiber bundle tip," Light: Science & Applications, 13, 168, (2024).
"Spatial and Fourier domain ptychography for high-throughput bio-imaging," Nature Protocols, 18, 2051-2083 (2023).
(Cover paper) "Concept, implementations and applications of Fourier ptychography," Nature Reviews Physics, 3, 207-223 (2021).
"Depth-multiplexed ptychographic microscopy for high-throughput imaging of stacked bio-specimens on a chip," Biosensors and Bioelectronics, 224,115049 (2023).
(Cover paper, ACS Editors' choice) "Blood-coated sensor for high-throughput ptychographic cytometry on a Blu-ray disc," ACS Sensors, 7(4), 1058-1067 (2022).
(Cover paper) "Resolution-Enhanced Parallel Coded Ptychography for High-Throughput Optical Imaging," ACS Photonics, 8(11), 3261-3271 (2021).
"Ptychographic sensor for large-scale lensless microbial monitoring with high spatiotemporal resolution," Biosensors and Bioelectronics, 196, 113699 (2022).
(Selected as Spotlight on Optics) "Lensless polarimetric coded ptychography for high-resolution, high-throughput gigapxiel birefringence imaging on a chip," Photonics Research, 11(12), 2242-2255 (2023).
(Editor's pick) "Synthetic aperture ptychography (SAP): coded sensor translation for joint spatial-Fourier bandwidth expansion," Photonics Research, 10(7), 1624-1632 (2022).
(Cover paper) "Optofluidic ptychography on a chip," Lab on a chip, 21, 4549-4556 (2021).
(Cover paper) "Wide-field, high-resolution lensless on-chip microscopy via near-field blind ptychographic modulation", Lab on a Chip, 20, 1058 - 1065 (2020).
"Wide-field, high-resolution Fourier ptychographic microscopy," Nature Photonics, 7, 739–745 (2013). (Featured by Nature).
"The ePetri dish, an on-chip cell imaging platform based on subpixel perspective sweeping microscopy (SPSM)," PNAS, 108, 16889-94 (2011). (Highlighted by Nature Methods).
"Surface-wave-enabled darkfield aperture for background suppression during weak signal detection," PNAS, 107, 9043 (2010).

Featured Research Projects

Ptychographic endoscopy

Synthetic aperture radar (SAR) utilizes an aircraft-carried antenna to emit electromagnetic pulses and detect the returning echoes. Inspired by SAR, we introduce synthetic aperture ptycho-endoscopy (SAPE) for micro-endoscopic imaging beyond the diffraction limit. SAPE operates by hand-holding a lensless fiber bundle tip to record coherent diffraction patterns from specimens. The fiber cores at the distal tip modulate the diffracted wavefield within a confined area, emulating the ‘airborne antenna’ in SAR. The handheld operation introduces positional shifts to the tip, analogous to the aircraft’s movement. These shifts facilitate the acquisition of a ptychogram and synthesize a large virtual aperture extending beyond the bundle’s physical limit. Our tests demonstrate the ability to resolve a 548-nm linewidth on a resolution target. The achieved space-bandwidth product is ~1.1 million effective pixels, a 36-fold increase compared to the original fiber bundle. The aperture synthesizing process surpasses the diffraction limit set by the probe’s maximum collection angle, opening new opportunities for lensless endoscopy in medical diagnostics and industrial inspection.

Coded ptychography

Coded ptychography is an advanced imaging technique that enhances resolution and imaging throughput by employing a coded surface to encode optical information. This technique combines high-resolution ptychographic imaging with a parallel, coded approach to significantly improve the numerical aperture and imaging speed. The coded surface modulates high-frequency object information into detectable intensity variations. The coded ptychographic platform replaces traditional objective lenses with this engineered surface, enabling super-resolution imaging beyond the diffraction limit. By translating the sample across the engineered surface, the technique captures diffraction patterns that are processed to reconstruct high-resolution images. It can achieve an imaging throughput orders of magnitude higher than conventional systems, acquiring gigapixel images in mere seconds. Our demonstrated throughput has been greater than the fastest whole slide scanner in the world: resolving 308-nm linewidth over a 240-mm2 effective field of view in 15 seconds.

Ptychographic non-line-of-sight imaging

Ptychographic Non-Line-of-Sight (pNLOS) imaging is an innovative technique that enables the visualization of objects hidden from direct view, with applications in fields such as surveillance, remote sensing, and light detection and ranging (LiDAR). This method combines the principles of ptychography with non-line-of-sight imaging to achieve depth-resolved visualization of obscured objects. In pNLOS imaging, a laser spot is scanned across a wall to illuminate hidden objects in an obscured region. The reflected wavefields from these objects travel back to the wall and are modulated by the wall’s complex-valued profile. The resulting diffraction patterns are captured by a camera. pNLOS provides a novel approach to overcoming the limitations of traditional imaging methods, offering new possibilities for applications in medical diagnostics, autonomous navigation, and security.

Spatially-coded Fourier ptychography (scFP)

scFP is an innovative imaging technique that synergizes Fourier ptychography with spatial-domain coded detection to achieve true quantitative phase imaging with uniform phase transfer characteristics. In this method, a flexible and detachable coded thin film is integrated into the FP setup by attaching it atop the image sensor. This thin film effectively converts object phase information into intensity variations, ensuring a uniform frequency response across the entire synthetic bandwidth. This approach significantly enhances the quality of ptychographic reconstructions and addresses issues such as refractive index underestimation, which are common in conventional FP and related techniques. The inclusion of the coded thin film introduces additional measurement diversity, allowing for more detailed and accurate phase imaging across various applications.

Optical physiology

Optical physiology leverages advanced optical imaging techniques to investigate physiological processes at the cellular and molecular levels, offering unprecedented insights into the dynamics of living organisms. One notable application in this field involves the use of genetically encoded calcium indicators, such as GCaMP6f, which allow for high-throughput functional characterization of neural activity. We aim to employ high-throughput optical recordings from intact dorsal root ganglia (DRGs) in mice to perform colorectal neural encoding. This approach enabled the precise measurement of calcium transients in response to physiological stimuli, providing detailed insights into neural function and sensory encoding.

Lab News

2024

05/20, Dr. Zheng was appointed the Director of the UConn Center for Biomedical & Bioengineering Innovation (CBBI).
07/03, Our work Ptycho-endoscopy on a lensless ultrathin fiber bundle tip has been published in Light: Science and Applications.
05/08, Our cover paper Snapshot macroscopic Fourier ptychography: far-field synthetic aperture imaging via illumination multiplexing and camera array acquisition has been published in Advanced Imaging.
02/07, Our invited paper Spatially-coded Fourier ptychography flexible and detachable coded thin films for quantitative phase imaging with uniform phase transfer characteristics has been published in Advanced Optical Materials
01/30, Dr. Zheng gave an invited talk at SPIE Photonics West.

2023

10/25, Dr. Zheng gave an invited talk at 'Ptychography at all wavelengths'.
09/16, Our paper Lensless polarimetric coded ptychography for high-resolution, high-throughput gigapxiel birefringence imaging on a chip has been published in Photonics Research, and selected as 'Spotlight on Optics'.
08/25, Qianhao Zhao from Tsinghua University has joined the research group. Welcome!
08/01, Pengming Song defended his thesis. Congratulations, Dr. Song!
06/16, Dr. Zheng gave an invited talk at Photonics North.
06/12, Our paper Spatial and Fourier domain ptychography for high-throughput bio-imaging has been published in Nature Protocols.
05/03, Our work Depth-multiplexed ptychographic microscopy for high-throughput imaging of stacked bio-specimens on a chip has been published in Biosensors and Bioelectronics
04/08, Our invited paper Freeform Illuminator for computational microscopy has been published in Intelligent Computing.
02/07, Our invited paper Optical ptychography for biomedical imaging: recent progress and future directions [Invited], has been published in Biomedical Optics Express.
01/26, our work Remote referencing strategy for high-resolution coded ptychographic imaging has been published in Optics Letters.

Lab News Before 2022

2022

07/05/2022, Our work on synthetic aperture ptychography has been selected as Editor's pick in Photonics Research.
05/31/2022, Our work on blood-coated sensor has been highlighted in Physics Today
05/16/2022, Our paper, Synthetic aperture ptychography: coded sensor translation for joint spatial-Fourier bandwidth expansion has been published in Photonics Research.
05/12/2022, Our paper, High-throughput digital pathology via a handheld, multiplexed, and AI-powered ptychographic whole slide scanner has been selected as Lab on a Chip Hot Articles 2022.
05/12/2022, Our paper, High-throughput digital pathology via a handheld, multiplexed, and AI-powered ptychographic whole slide scanner has been published in Lab on a Chip.
05/03/2022, Our work has been highlighted in Microscope alternation on path to enhancing bioimaging by Laser Focus World.
04/08/2022, Our paper Blood-coated sensor for high-throughput ptychographic cytometry on a Blu-ray disc has been selected by ACS editors' choice for free access.
04/07/2022, Our cover paper, Blood-coated sensor for high-throughput ptychographic cytometry on a Blu-ray disc has been published in ACS Sensors.

2021

11/30/2021, Shaowei Jiang has successfully defended his Ph.D. thesis. Congratulations, Dr. Jiang!
11/12/2021, Our paper, Deep learning-enabled whole slide imaging (DeepWSI): oil-immersion quality using dry objectives, longer depth of field, higher system throughput, and better functionality has been published in Optics Express.
10/29/2021, Our paper, Quantitative multi-height phase retrieval via a coded image sensor has been published in Biomedical Optics Express.
10/20/2021, Our cover paper, Optofluidic ptychography on a chip has been published in Lab on a Chip.
10/14/2021, Our cover paper, Resolution-Enhanced Parallel Coded Ptychography for High-Throughput Optical Imaging, has been published in ACS Photonics.
10/10/2021, Our paper, High-throughput lensless whole slide imaging via continuous height-varying modulation of a tilted sensor, has been highlighted by Editor's pick in Optics Letters.
10/08/2021, Our paper, Ptychographic sensor for large-scale lensless microbial monitoring with high spatiotemporal resolution, has been published in Biosensors and Bioelectronics.
09/28/2021, Our invited news and views paper, Effective color transfer enables rapid computational microscopy for digital pathology, has been published in Science China Physics, Mechanics & Astronomy.
08/16/2021, Zichao Bian has successfully defended his Ph.D. thesis. Congratulations, Dr. Bian!
03/11/2021, Our paper, High-throughput functional characterization of visceral afferents by optical recordings from thoracolumbar and lumbosacral dorsal root ganglia, has been published in Frontiers in Neuroscience.
02/10/2021, Our cover paper Concept, implementations and applications of Fourier ptychography has been published in Nature Reviews Physics.

2020

09/20/2020, Our review paper on autofocusing technologies has been published in Journal of Biophotonics.
09/01/2020, Our group has received a new grant from NSF.
07/01/2020, Our invited paper, Diffuser modulation enables quantitative lensless microscopy, has been published in Biophotonics.
06/25/2020, Our paper, Virtual brightfield and fluorescence staining for Fourier ptychography via unsupervised deep learning, has been published in Optics Letters.
05/22/2020, Our paper on Multispectral lensless microscopy has been published in Optics Letters.

02/10/2020, Our cover paper, Wide-field, high-resolution lensless on-chip microscopy via near-field blind ptychographic modulation, has been published in Lab on a Chip.
01/01/2019, Our OpenWSI: a low-cost, high-throughput whole slide imaging system paper has been highlighted by Editor's pick in Optics Letters.

2019

11/22/2019, Our OpenWSI: a low-cost, high-throughput whole slide imaging system paper has been published in Optics Letters.
09/15/2019, Our $5 ptychographic modulation engine invited paper has been published in Journal of Physics D: Applied Physics.
07/15/2019, Our super-resolution microscopy via ptychographic structured modulation paper has been published in Optics Letters.
05/28/2019, Our color multiplexed single-shot autofocusing invited paper has been published in Quantitative Imaging in Medicine and Surgery.
05/13/2019, Our full-field Fourier ptychography invited paper has been published in APL Photonics.
04/12/2019, Our lensless imaging via translated speckle illumination paper has been highlighted by Editor's pick in Optics Letters.
04/01/2019, Our lensless imaging via translated speckle illumination paper has been published in Optics Letters.
02/20/2019, Our near-field Fourier ptychography paper has been published in Optics Express.
01/06/2019, Our macroscale confocal imaging paper has been published in Optics Letters.

2018

11/30/2018, Jun Liao has successfully defended his Ph.D. thesis!
08/02/2018, Our terapixel hyperspectral imaging paper has been published in the Journal of Biomedical Optics.
07/15/2018, Dr. Hoshino and Dr. Zheng received an NSF grant to develop a measurement system for micro/mesoscale elastography.
06/16/2018, Our mask-modulated lensless imaging paper has been published in APL Photonics.
05/06/2018, Our neural network model for solving phase retrieval paper has been published in Biomedical Optics Express.
04/18/2018, Kaikai Guo has successfully defended his Ph.D. thesis! Congrats!
03/08/2018, Our Transform-/multi-domain deep learning for whole slide imaging paper has been published in Biomedical Optics Express.

2017

12/18/2017, Our fluorescence imaging through turbid layer paper has been published in Biomedical Optics Express.
10/01/2017, Prof. Feng Pan from Beihang University has joined our group as a visiting scholar.
07/31/2017, Our two-LED-based focus survey paper has been published in Optics Letters.
06/10/2017, Dr. Zheng received an NSF grant to develop the whole slide imaging platform.
05/02/2017, the Fourier ptychography method has been written in Prof. Joseph Goodman's famous textbook Introduction to Fourier Optics (4th Edition).
03/01/2017, Our multichannel microscopy paper is published in the Journal of Biophotonics.

2016

12/12/2016, Our fluorescence whole slide imaging paper is listed as the top downloaded paper in Biomedical Optics Express.
11/30/2016, Our Angular light modulator paper has been published in Optics Express.
10/27/2016, Our fluorescence whole slide imaging paper has been published in Biomedical Optics Express.
07/12/2016, Kaikai Guo received the FEI fellowship to develop the Fourier ptychography approach.
07/12/2016, Our lensless multilayer single-pixel fluorescence imaging paper is listed as the top downloaded paper in Biomedical Optics Express.
06/01/2016, Our lensless multilayer single-pixel fluorescence imaging paper has been published in Biomedical Optics Express.
05/18/2016, Our book on Fourier ptychography has been published by IOP Press: Fourier Ptychographic Imaging: a MATLAB Tutorial.
04/19/2016, We got a Biopipeline grant from Connecticut Innovation Venture Capital to study and validate the digital pathology system.
04/18/2016, Charmi Patel received an Idea Grant (innovative project for undergrad) to develop the robotic arm for the digital pathology system.
02/10/2016, Dr. Zheng received an NSF grant to develop the InstantScope platform.

2015

12/05/2015, Our invited paper Fourier Ptychography for Brightfield, Phase, Darkfield, Reflective, Multi-slice, and Fluorescence Imaging has been published in IEEE Journal of Selected Topics in Quantum Electronics.
11/12/2015, Our paper Recovering higher dimensional image data using multiplexed structured illumination has been published in Optics Express.
09/03/2015, Our paper InstantScope: a low-cost whole slide imaging system with instant focal plane detection is listed as the top downloaded paper in Biomedical Optics Express.
08/16/2015, Our paper Resolution doubling with a reduced number of image acquisitions is listed as the top downloaded paper in Biomedical Optics Express.
08/04/2015, Our paper InstantScope: a low-cost whole slide imaging system with instant focal plane detection has been published in Biomedical Optics Express. The operation of this platform can be seen in this video.
07/29/2015, Our paper Incoherent Fourier ptychographic photography using structured light is listed as the top downloaded paper in Photonics Research.
07/17/2015, Our paper Resolution doubling with a reduced number of image acquisitions has been published in Biomedical Optics Express.
05/20/2015, Dr. Zheng and Kaikai Guo received a grant from Connecticut Innovation Venture Capital to optimize the gigapixel microscope platform.
05/20/2015, Dr. Zheng received an NSF grant to further develop the Fourier ptychography approach for biomedical applications.
05/18/2015, Digital eyeglass was featured at Spotlight on Optics.
04/27/2015, We have developed a digital eyeglass for improving visual contrast and reducing vision glare LCD-based digital eyeglass for modulating spatial-angular information (Optics Express).
02/27/2015, Our paper Optimization of sampling pattern and the design of Fourier ptychographic illuminator has been published in Optics Express.
02/05/2015, Our paper Microscopy illumination engineering using a low-cost liquid crystal display is listed as the monthly most downloaded paper in Biomedical Optics Express.
01/15/2015, Our paper Microscopy illumination engineering using a low-cost liquid crystal display has been published in Biomedical Optics Express.
01/07/2015, News cover from Laser Focus World on our FPscope.
01/05/2015, Our paper Incoherent Fourier ptychographic photography using structured light has been published in Photonics Research.

2014

11/26/2014, The gigapixel Fourier ptychographic microscopy is listed as one of the three finalists of the prestigious Prism Award.
10/11/2014, Our paper FPscope: a field-portable high-resolution microscope using a cellphone lens is listed as the top downloaded paper in Biomedical Optics Express.
10/03/2014, Our pattern-illuminated Fourier ptychography work is listed as the top downloaded paper in Optics Express.
08/29/2014, Our paper FPscope: a field-portable high-resolution microscope using a cellphone lens has been published in Biomedical Optics Express.
08/22/2014, We have extended the Fourier ptychography approach for fluorescence microscopy High-resolution fluorescence imaging via pattern-illuminated Fourier ptychography in Optics Express.
05/29/2014, We have extended the Fourier ptychography approach for 3D imaging and macroscopic imaging beyond the diffraction limit, Aperture-scanning Fourier ptychography for 3D refocusing and super-resolution macroscopic imaging in Optics Express.
05/06/2014, Pariksheet Nanda from Andor Technology will join our group, welcome!
05/06/2014, Our paper Spectral multiplexing and coherent-state decomposition in Fourier ptychographic imaging has been published in Biomedical Optics Express.
03/29/2014, Our invited paper Breakthroughs in Photonics 2013: Fourier ptychographic imaging has been published in IEEE Photonics Journal (the special issue of Breakthrough in Phonics 2013).
03/29/2014, Our Fourier ptychography approach is featured by Optics and Photonics News as the cover paper.
02/28/2014, Our paper Sparsely sampled Fourier ptychography has been published in Optics Express.
01/13/2014, Our paper 0.5 gigapixel microscopy using a flatbed scanner is listed as a top-downloaded paper in Biomedical Optics Express.

2013

12/23/2013, Dr. Zheng will give an invited featured presentation, Pushing the resolution limit with a simple LED array, at the Second Annual Digital Pathology Conference (Feb 10-12, 2014, San Francisco, CA).
12/02/2013, Our first paper Adaptive system correction for robust Fourier ptychographic imaging, has been published in Optics Express.
11/01/2013, Our Fourier ptychography work has been featured in Nature!

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