Lensless ghost imaging has attracted much interest in recent years due to its profound physics and potential applications. In this paper we report studies of the robust properties of the lensless ghost imaging system ...Lensless ghost imaging has attracted much interest in recent years due to its profound physics and potential applications. In this paper we report studies of the robust properties of the lensless ghost imaging system with a pseudo-thermal light source in a strongly scattering medium. The effects of the positions of the strong medium on the ghost imaging are investigated. In the lensless ghost imaging system, a pseudo-thermal light is split into two correlated beams by a beam splitter. One beam goes to a charge-coupled detector camera, labeled as CCD2. The other beam goes to an object and then is collected in another charge-coupled detector camera, labeled as CCD1, which serves as a bucket detector. When the strong medium, a pane of ground glass disk, is placed between the object and CCD1, the bucket detector, the quality of ghost imaging is barely affected and a good image could still be obtained. The quality of the ghost imaging can also be maintained, even when the ground glass is rotating, which is the strongest scattering medium so far. However, when the strongly scattering medium is present in the optical path from the light source to CCD2 or the object, the lensless ghost imaging system hardly retrieves the image of the object. A theoretical analysis in terms of the second-order correlation function is also provided.展开更多
We propose optical experiments to study the depth of field for a thermal light lensless ghost imaging system. It is proved that the diaphragm is an important factor to influence the depth of field, and the ghost image...We propose optical experiments to study the depth of field for a thermal light lensless ghost imaging system. It is proved that the diaphragm is an important factor to influence the depth of field, and the ghost images of two detected objects with longitudinal distance less than the depth of field can be achieved simultaneously. The longitudinal coherence scale of the thermal light lensless ghost imaging determines the depth of field. Theoretical analysis can well explain the experimental results.展开更多
Snapshot hyperspectral imaging based on a diffractive optical element(DOE)is increasingly featured in recent progress in deep optics.Despite remarkable advances in spatial and spectral resolutions,the limitations of c...Snapshot hyperspectral imaging based on a diffractive optical element(DOE)is increasingly featured in recent progress in deep optics.Despite remarkable advances in spatial and spectral resolutions,the limitations of current photolithography technology have prevented the fabricated DOE from being designed at ideal heights and with high diffraction efficiency,diminishing the effectiveness of coded imaging and reconstruction accuracy in some bands.Here,we propose,to our knowledge,a new lensless efficient snapshot hyperspectral imaging(LESHI)system that utilizes a liquid-crystal-on-silicon spatial light modulator(LCoS-SLM)to replace the traditionally fabricated DOE,resulting in high modulation levels and reconstruction accuracy.Beyond the single-lens imaging model,the system can leverage the switch ability of LCoS-SLM to implement distributed diffractive optics(DDO)imaging and enhance diffraction efficiency across the full visible spectrum.Using the proposed method,we develop a proof-of-concept prototype with an image resolution of 1920×1080 pixels,an effective spatial resolution of 41.74μm,and a spectral resolution of 10 nm,while improving the average diffraction efficiency from 0.75 to0.91 over the visible wavelength range(400-700 nm).Additionally,LESHI allows the focal length to be adjusted from 50 mm to 100 mm without the need for additional optical components,providing a cost-effective and timesaving solution for real-time on-site debugging.LESHI is the first imaging modality,to the best of our knowledge,to use dynamic diffractive optics and snapshot hyperspectral imaging,offering a completely new approach to computational spectral imaging and deep optics.展开更多
Lensless fiber endomicroscopy,an emergent paradigm shift for minimally-invasive microscopic optical imaging and targeted light delivery,holds transformative potential,especially in biomedicine.Leveraging holographic d...Lensless fiber endomicroscopy,an emergent paradigm shift for minimally-invasive microscopic optical imaging and targeted light delivery,holds transformative potential,especially in biomedicine.Leveraging holographic detection and physical or computational wavefront correction,it enables three-dimensional imaging in an unprecedentedly small footprint,which is crucial for various applications such as brain surgery.This perspective reviews the recent breakthroughs,highlighting potential emerging applications,and pinpointing gaps between innovation and real-world applications.As the research in this realm accelerates,the novel breakthroughs and existing frontiers highlighted in this perspective can be used as guidelines for researchers joining this exciting domain.展开更多
Lensless imaging is an approach to microscopy in which a high-resolution image of an object is reconstructed from one or more measured diffraction patterns,providing a solution in situations where the use of imaging o...Lensless imaging is an approach to microscopy in which a high-resolution image of an object is reconstructed from one or more measured diffraction patterns,providing a solution in situations where the use of imaging optics is not possible.However,current lensless imaging methods are typically limited by the need for a light source with a narrow,stable and accurately known spectrum.We have developed a general approach to lensless imaging without spectral bandwidth limitations or sample requirements.We use two time-delayed coherent light pulses and show that scanning the pulse-to-pulse time delay allows the reconstruction of diffraction-limited images for all the spectral components in the pulse.In addition,we introduce an iterative phase retrieval algorithm that uses these spectrally resolved Fresnel diffraction patterns to obtain high-resolution images of complex extended objects.We demonstrate this two-pulse imaging method with octave-spanning visible light sources,in both transmission and reflection geometries,and with broadband extreme-ultraviolet radiation from a high-harmonic generation source.Our approach enables effective use of low-flux ultra-broadband sources,such as table-top high-harmonic generation systems,for high-resolution imaging.展开更多
In this paper,an irregular displacement-based lensless wide-field microscopy imaging platform is presented by combining digital in-line holography and computational pixel super-resolution using multi-frame processing....In this paper,an irregular displacement-based lensless wide-field microscopy imaging platform is presented by combining digital in-line holography and computational pixel super-resolution using multi-frame processing.The samples are illuminated by a nearly coherent illumination system,where the hologram shadows are projected into a complementary metal-oxide semiconductor-based imaging sensor.To increase the resolution,a multi-frame pixel resolution approach is employed to produce a single holographic image from multiple frame observations of the scene,with small planar displacements.Displacements are resolved by a hybrid approach:(i)alignment of the LR images by a fast feature-based registration method,and(ii)fine adjustment of the sub-pixel information using a continuous optimization approach designed to find the global optimum solution.Numerical method for phase-retrieval is applied to decode the signal and reconstruct the morphological details of the analyzed sample.The presented approach was evaluated with various biological samples including sperm and platelets,whose dimensions are in the order of a few microns.The obtained results demonstrate a spatial resolution of 1.55 μm on a field-of-view of<30 mm^(2).展开更多
红外波段位于可见光波段与微波波段之间,相比较可见光具有热效应、不可见以及穿透性强等特点。随着以红外激光作为相干光源的红外全息技术迅速发展,红外全息技术在无损检测和无透镜成像领域已经表现出可见光全息技术无可比拟的优势。本...红外波段位于可见光波段与微波波段之间,相比较可见光具有热效应、不可见以及穿透性强等特点。随着以红外激光作为相干光源的红外全息技术迅速发展,红外全息技术在无损检测和无透镜成像领域已经表现出可见光全息技术无可比拟的优势。本文回顾了红外全息技术的发展历程,介绍了红外数字全息(Infrared Digital Holography,IRDH)技术、扫描红外数字全息(Scanning Infrared Digital Holography,SIRDH)技术、红外数字全息显微(Infrared Digital Holographic Microscopy,IRDHM)技术的研究状况,归纳总结了红外全息技术的检测优势和典型应用情况,最后展望了红外全息技术的未来发展趋势。展开更多
A lensless Vanderlugt optical correlator using two phase-only spatial light modulators （SLMs） is proposed. The SLMs are used for displaying input and filter patterns respectively. The SLMs are also used as programma...A lensless Vanderlugt optical correlator using two phase-only spatial light modulators （SLMs） is proposed. The SLMs are used for displaying input and filter patterns respectively. The SLMs are also used as programmable lenses in order to realize the lensless construction. This lensless system is simple and its alignment adjustment is easy. The performance of the SLMs as programmable lenses is also described.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11175094 and 91221205)the National Basic Research Program of China(Grant No.2015CB921002)partially supported by the Basic Research Fund of Beijing Institute of Technology(Grant No.20141842005)
文摘Lensless ghost imaging has attracted much interest in recent years due to its profound physics and potential applications. In this paper we report studies of the robust properties of the lensless ghost imaging system with a pseudo-thermal light source in a strongly scattering medium. The effects of the positions of the strong medium on the ghost imaging are investigated. In the lensless ghost imaging system, a pseudo-thermal light is split into two correlated beams by a beam splitter. One beam goes to a charge-coupled detector camera, labeled as CCD2. The other beam goes to an object and then is collected in another charge-coupled detector camera, labeled as CCD1, which serves as a bucket detector. When the strong medium, a pane of ground glass disk, is placed between the object and CCD1, the bucket detector, the quality of ghost imaging is barely affected and a good image could still be obtained. The quality of the ghost imaging can also be maintained, even when the ground glass is rotating, which is the strongest scattering medium so far. However, when the strongly scattering medium is present in the optical path from the light source to CCD2 or the object, the lensless ghost imaging system hardly retrieves the image of the object. A theoretical analysis in terms of the second-order correlation function is also provided.
基金Supported by the Beijing Natural Science Foundation under Grant No 4133086the Fundamental Research Funds for th Central Universities under Grant No 2-9-2014-022
文摘We propose optical experiments to study the depth of field for a thermal light lensless ghost imaging system. It is proved that the diaphragm is an important factor to influence the depth of field, and the ghost images of two detected objects with longitudinal distance less than the depth of field can be achieved simultaneously. The longitudinal coherence scale of the thermal light lensless ghost imaging determines the depth of field. Theoretical analysis can well explain the experimental results.
基金National Key Research and Development Program of China(2023YFB3611500)National Natural Science Foundation of China(62131003,62332003)A*STAR RIE2020 AME Programmatic Funding(A18A7b0058)。
文摘Snapshot hyperspectral imaging based on a diffractive optical element(DOE)is increasingly featured in recent progress in deep optics.Despite remarkable advances in spatial and spectral resolutions,the limitations of current photolithography technology have prevented the fabricated DOE from being designed at ideal heights and with high diffraction efficiency,diminishing the effectiveness of coded imaging and reconstruction accuracy in some bands.Here,we propose,to our knowledge,a new lensless efficient snapshot hyperspectral imaging(LESHI)system that utilizes a liquid-crystal-on-silicon spatial light modulator(LCoS-SLM)to replace the traditionally fabricated DOE,resulting in high modulation levels and reconstruction accuracy.Beyond the single-lens imaging model,the system can leverage the switch ability of LCoS-SLM to implement distributed diffractive optics(DDO)imaging and enhance diffraction efficiency across the full visible spectrum.Using the proposed method,we develop a proof-of-concept prototype with an image resolution of 1920×1080 pixels,an effective spatial resolution of 41.74μm,and a spectral resolution of 10 nm,while improving the average diffraction efficiency from 0.75 to0.91 over the visible wavelength range(400-700 nm).Additionally,LESHI allows the focal length to be adjusted from 50 mm to 100 mm without the need for additional optical components,providing a cost-effective and timesaving solution for real-time on-site debugging.LESHI is the first imaging modality,to the best of our knowledge,to use dynamic diffractive optics and snapshot hyperspectral imaging,offering a completely new approach to computational spectral imaging and deep optics.
基金organized by Projekt DEAL.German Research Foundation(DFG)grant CZ55/40,CZ55/47European Research Council(ERC)Horizon 2020 research and innovation program(grant no.101002406)+1 种基金Shanghai Artificial Intelligence Laboratory,National Key R&D Program of China(2022ZD0160100)Else Kroner Fresenius Center for digital Heath(EKFZ)and Competence Center for Biomedical Computational Laser Systems(BIOLAS).
文摘Lensless fiber endomicroscopy,an emergent paradigm shift for minimally-invasive microscopic optical imaging and targeted light delivery,holds transformative potential,especially in biomedicine.Leveraging holographic detection and physical or computational wavefront correction,it enables three-dimensional imaging in an unprecedentedly small footprint,which is crucial for various applications such as brain surgery.This perspective reviews the recent breakthroughs,highlighting potential emerging applications,and pinpointing gaps between innovation and real-world applications.As the research in this realm accelerates,the novel breakthroughs and existing frontiers highlighted in this perspective can be used as guidelines for researchers joining this exciting domain.
基金This work is financed in part by an NWO-groot investment grant of the Netherlands Organisation for Scientific Research(NWO)and Laserlab Europe(JRA Bioptichal)SW acknowledges support from NWO Veni grant 680-47-402.
文摘Lensless imaging is an approach to microscopy in which a high-resolution image of an object is reconstructed from one or more measured diffraction patterns,providing a solution in situations where the use of imaging optics is not possible.However,current lensless imaging methods are typically limited by the need for a light source with a narrow,stable and accurately known spectrum.We have developed a general approach to lensless imaging without spectral bandwidth limitations or sample requirements.We use two time-delayed coherent light pulses and show that scanning the pulse-to-pulse time delay allows the reconstruction of diffraction-limited images for all the spectral components in the pulse.In addition,we introduce an iterative phase retrieval algorithm that uses these spectrally resolved Fresnel diffraction patterns to obtain high-resolution images of complex extended objects.We demonstrate this two-pulse imaging method with octave-spanning visible light sources,in both transmission and reflection geometries,and with broadband extreme-ultraviolet radiation from a high-harmonic generation source.Our approach enables effective use of low-flux ultra-broadband sources,such as table-top high-harmonic generation systems,for high-resolution imaging.
基金We would like to acknowledge National Institute of Health(NIH)NIH R01AI093282,NIH R01AI081534,NIH U54EB15408,NIH R21AI087107,and Brigham and Women’s Hospital-BRI Translatable Technologies and Care Innovation GrantWe would also like to acknowledge the support provided by the Brazilian National Council for Scientific and Technological Development(process 551967/2011-0)
文摘In this paper,an irregular displacement-based lensless wide-field microscopy imaging platform is presented by combining digital in-line holography and computational pixel super-resolution using multi-frame processing.The samples are illuminated by a nearly coherent illumination system,where the hologram shadows are projected into a complementary metal-oxide semiconductor-based imaging sensor.To increase the resolution,a multi-frame pixel resolution approach is employed to produce a single holographic image from multiple frame observations of the scene,with small planar displacements.Displacements are resolved by a hybrid approach:(i)alignment of the LR images by a fast feature-based registration method,and(ii)fine adjustment of the sub-pixel information using a continuous optimization approach designed to find the global optimum solution.Numerical method for phase-retrieval is applied to decode the signal and reconstruct the morphological details of the analyzed sample.The presented approach was evaluated with various biological samples including sperm and platelets,whose dimensions are in the order of a few microns.The obtained results demonstrate a spatial resolution of 1.55 μm on a field-of-view of<30 mm^(2).
文摘红外波段位于可见光波段与微波波段之间,相比较可见光具有热效应、不可见以及穿透性强等特点。随着以红外激光作为相干光源的红外全息技术迅速发展,红外全息技术在无损检测和无透镜成像领域已经表现出可见光全息技术无可比拟的优势。本文回顾了红外全息技术的发展历程,介绍了红外数字全息(Infrared Digital Holography,IRDH)技术、扫描红外数字全息(Scanning Infrared Digital Holography,SIRDH)技术、红外数字全息显微(Infrared Digital Holographic Microscopy,IRDHM)技术的研究状况,归纳总结了红外全息技术的检测优势和典型应用情况,最后展望了红外全息技术的未来发展趋势。
文摘A lensless Vanderlugt optical correlator using two phase-only spatial light modulators （SLMs） is proposed. The SLMs are used for displaying input and filter patterns respectively. The SLMs are also used as programmable lenses in order to realize the lensless construction. This lensless system is simple and its alignment adjustment is easy. The performance of the SLMs as programmable lenses is also described.
