Spatial optical analog differentiation allows ultrahigh-speed and low-power-consumption of image processing, as well as label-free imaging of transparent biological objects. Optical analog differentiation with broadband and incoherent sources is appealing for its multi-channels and multi-task information processing, as well as the high-quality differentiation imaging. Currently, broadband and incoherent optical differentiation is still challenging. Here, a compact and broadband achromatic optical spatial differentiator is demonstrated based on the intrinsic spin–orbit coupling in a natural thin crystal. By inserting a uniaxial crystal just before the camera of a conventional microscope, the spin to orbit conversion will embed an optical vortex to the image field and make a second-order topological spatial differentiation to the field, thus an isotropic differential image will be captured by the camera. The wavelength-independent property of the intrinsic spin–orbit coupling effect allows us to achieve broadband analog computing and achromatic spatial differentiation imaging. With this differentiation imaging method, both amplitude and pure phase objects are detected with high contrast. Transparent living cells and biological tissues are imaged with their edge contours and intracellular details protruded in the edge detection mode and edge enhancement mode, respectively. These findings pave the way for optical analog computing with broadband incoherent light sources and concurrently drive the advancement of high-performance and cost-effective phase contrast imaging.
{"title":"Spin–orbit optical broadband achromatic spatial differentiation imaging","authors":"Hongwei Yang, Weichao Xie, Huifeng Chen, Mengyuan Xie, Jieyuan Tang, Huadan Zheng, Yongchun Zhong, Jianhui Yu, Zhe Chen, Wenguo Zhu","doi":"10.1364/optica.524984","DOIUrl":"https://doi.org/10.1364/optica.524984","url":null,"abstract":"Spatial optical analog differentiation allows ultrahigh-speed and low-power-consumption of image processing, as well as label-free imaging of transparent biological objects. Optical analog differentiation with broadband and incoherent sources is appealing for its multi-channels and multi-task information processing, as well as the high-quality differentiation imaging. Currently, broadband and incoherent optical differentiation is still challenging. Here, a compact and broadband achromatic optical spatial differentiator is demonstrated based on the intrinsic spin–orbit coupling in a natural thin crystal. By inserting a uniaxial crystal just before the camera of a conventional microscope, the spin to orbit conversion will embed an optical vortex to the image field and make a second-order topological spatial differentiation to the field, thus an isotropic differential image will be captured by the camera. The wavelength-independent property of the intrinsic spin–orbit coupling effect allows us to achieve broadband analog computing and achromatic spatial differentiation imaging. With this differentiation imaging method, both amplitude and pure phase objects are detected with high contrast. Transparent living cells and biological tissues are imaged with their edge contours and intracellular details protruded in the edge detection mode and edge enhancement mode, respectively. These findings pave the way for optical analog computing with broadband incoherent light sources and concurrently drive the advancement of high-performance and cost-effective phase contrast imaging.","PeriodicalId":19515,"journal":{"name":"Optica","volume":"355 1","pages":""},"PeriodicalIF":10.4,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mahdi Mazaheri, Kiarash Kasaian, David Albrecht, Jan Renger, Tobias Utikal, Cornelia Holler, Vahid Sandoghdar
Interferometric scattering (iSCAT) microscopy has demonstrated unparalleled performance among label-free optical methods for detecting and imaging isolated nanoparticles and molecules. However, when imaging complex structures such as biological cells, the superposition of the scattering fields from different locations of the sample leads to a speckle-like background, posing a significant challenge in deciphering fine features. Here, we show that by controlling the spatial coherence of the illumination, one can eliminate the spurious speckle without sacrificing sensitivity. We demonstrate this approach by positioning a rotating diffuser coupled with an adjustable lens and an iris in the illumination path. We report on imaging at a high frame rate of 25 kHz and across a large field of view of 100µm×100µm, while maintaining diffraction-limited resolution. We showcase the advantages of these features by three-dimensional (3D) tracking over 1000 vesicles in a single COS-7 cell and by imaging the dynamics of the endoplasmic reticulum (ER) network. Our approach opens the door to the combination of label-free imaging, sensitive detection, and 3D high-speed tracking using wide-field iSCAT microscopy.
{"title":"iSCAT microscopy and particle tracking with tailored spatial coherence","authors":"Mahdi Mazaheri, Kiarash Kasaian, David Albrecht, Jan Renger, Tobias Utikal, Cornelia Holler, Vahid Sandoghdar","doi":"10.1364/optica.523788","DOIUrl":"https://doi.org/10.1364/optica.523788","url":null,"abstract":"Interferometric scattering (iSCAT) microscopy has demonstrated unparalleled performance among label-free optical methods for detecting and imaging isolated nanoparticles and molecules. However, when imaging complex structures such as biological cells, the superposition of the scattering fields from different locations of the sample leads to a speckle-like background, posing a significant challenge in deciphering fine features. Here, we show that by controlling the spatial coherence of the illumination, one can eliminate the spurious speckle without sacrificing sensitivity. We demonstrate this approach by positioning a rotating diffuser coupled with an adjustable lens and an iris in the illumination path. We report on imaging at a high frame rate of 25 kHz and across a large field of view of 100µm×100µm, while maintaining diffraction-limited resolution. We showcase the advantages of these features by three-dimensional (3D) tracking over 1000 vesicles in a single COS-7 cell and by imaging the dynamics of the endoplasmic reticulum (ER) network. Our approach opens the door to the combination of label-free imaging, sensitive detection, and 3D high-speed tracking using wide-field iSCAT microscopy.","PeriodicalId":19515,"journal":{"name":"Optica","volume":"1412 1","pages":""},"PeriodicalIF":10.4,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Photonic orbital angular momentum (OAM) carried by phase-structured vortex light is an important and promising resource for the ever-increasing demand towards high-capacity data information due to its intrinsic unlimited dimensionality. Large superpositions of OAM are easy to be produced, but on-demand generation of arbitrary OAM spectra such as an OAM comb similar to a frequency comb is still a challenge; especially, the on-demand OAM comb and arbitrary multi-OAM modes have not yet been realized at the source. Here we report a versatile at-source strategy for developing a flexibly and dynamically switchable on-demand digital OAM comb laser for the first time, to our knowledge, by controlling the phase degree of freedom itself rather than any proxy. For this aim, we present a crucial design idea that a nested ring cavity configuration is composed of a degenerate cavity embedded into a stable ring cavity and a pair of conjugate two-fold symmetric multi-spiral-phase digital holographic mirrors loaded onto reflective phase-only spatial light modulators. In the nested ring cavity, the stable ring cavity and the degenerate cavity meet the requirements of high spatial coherence and supporting any transverse mode, respectively. The paired conjugate holographic mirrors located in mutual object and image planes circumvent the competing issue among different OAM modes and control the number and chirality of modes in OAM combs with ease. Our strategy has also universality as it has the ability of encoding OAM spectra with arbitrary distribution. The realization of a dynamic on-demand multi-OAM-mode laser is an important progress in the infancy of multi-OAM-mode sources. Our idea provides a promising solution for development of emerging high-dimensional technologies; in the future, there will be increasing opportunities in the fundamentals and applications of high-dimensional OAM modes, and beyond. Our strategy not only contributes to the development of new laser technology, but also provides a toolbox for both linear and nonlinear generation of the multiple OAM modes at the source.
{"title":"On-demand orbital angular momentum comb from a digital laser","authors":"Zhi-Cheng Ren, Li Fan, Zi-Mo Cheng, Zhi-Feng Liu, Yan-Chao Lou, Shuang-Yin Huang, Chao Chen, Yongnan Li, Chenghou Tu, Jianping Ding, Xi-Lin Wang, Hui-Tian Wang","doi":"10.1364/optica.529425","DOIUrl":"https://doi.org/10.1364/optica.529425","url":null,"abstract":"Photonic orbital angular momentum (OAM) carried by phase-structured vortex light is an important and promising resource for the ever-increasing demand towards high-capacity data information due to its intrinsic unlimited dimensionality. Large superpositions of OAM are easy to be produced, but on-demand generation of arbitrary OAM spectra such as an OAM comb similar to a frequency comb is still a challenge; especially, the on-demand OAM comb and arbitrary multi-OAM modes have not yet been realized at the source. Here we report a versatile at-source strategy for developing a flexibly and dynamically switchable on-demand digital OAM comb laser for the first time, to our knowledge, by controlling the phase degree of freedom itself rather than any proxy. For this aim, we present a crucial design idea that a nested ring cavity configuration is composed of a degenerate cavity embedded into a stable ring cavity and a pair of conjugate two-fold symmetric multi-spiral-phase digital holographic mirrors loaded onto reflective phase-only spatial light modulators. In the nested ring cavity, the stable ring cavity and the degenerate cavity meet the requirements of high spatial coherence and supporting any transverse mode, respectively. The paired conjugate holographic mirrors located in mutual object and image planes circumvent the competing issue among different OAM modes and control the number and chirality of modes in OAM combs with ease. Our strategy has also universality as it has the ability of encoding OAM spectra with arbitrary distribution. The realization of a dynamic on-demand multi-OAM-mode laser is an important progress in the infancy of multi-OAM-mode sources. Our idea provides a promising solution for development of emerging high-dimensional technologies; in the future, there will be increasing opportunities in the fundamentals and applications of high-dimensional OAM modes, and beyond. Our strategy not only contributes to the development of new laser technology, but also provides a toolbox for both linear and nonlinear generation of the multiple OAM modes at the source.","PeriodicalId":19515,"journal":{"name":"Optica","volume":"11 1","pages":""},"PeriodicalIF":10.4,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alexander J. Littlefield, Jack Huang, Mason L. Holley, Nikita B. Duggar, Jingxing Gao, Dajie Xie, Corey A. Richards, Truman Silberg, Ujaan Purakayastha, Jesse Herr, Christian R. Ocier, Xiangrui Deng, Xiaoli Wang, Paul V. Braun, Lynford L. Goddard
Photonic integrated circuits (PICs) are vital for high-speed data transmission. However, optical routing is limited in PICs composed of only one or a few stacked planes. Further, coupling losses must be low in deployed systems. Previously, we developed the subsurface controllable refractive index via beam exposure (SCRIBE) technique to write accurate 3D gradient refractive index (GRIN) profiles within a mesoporous silica scaffold. Here, we apply SCRIBE to fabricate low loss, broadband, polarization insensitive, fiber-coupled, single-mode volumetric interconnects that include waveguides traversing arbitrary 3D paths. By seamlessly integrating mode-matching subsurface lenses and GRIN waveguide tapers, calibrating for positional writing errors, implementing multipass exposure, automating alignment, and switching to antireflection coated fibers, we reduced the insertion loss for a fiber-PIC-fiber interconnect from 50 to 2.14 dB, or 1.47 dB, excluding the fiber array’s loss. Further, we establish an upper bound of 0.45 dB loss per coupler. We report quality factors of 27,000 and 77,000 and bending losses of 6 and 3 dB/cm for 15 and 30 µm radii microrings, respectively. We also demonstrate Bézier escalators, polarization-rotating and polarization-splitting interconnects, and a seven-channel 25 µm pitch volumetric interconnect. The SCRIBE platform presents a clear path toward realizing 3D PICs with unique functionality.
{"title":"Low loss fiber-coupled volumetric interconnects fabricated via direct laser writing","authors":"Alexander J. Littlefield, Jack Huang, Mason L. Holley, Nikita B. Duggar, Jingxing Gao, Dajie Xie, Corey A. Richards, Truman Silberg, Ujaan Purakayastha, Jesse Herr, Christian R. Ocier, Xiangrui Deng, Xiaoli Wang, Paul V. Braun, Lynford L. Goddard","doi":"10.1364/optica.525444","DOIUrl":"https://doi.org/10.1364/optica.525444","url":null,"abstract":"Photonic integrated circuits (PICs) are vital for high-speed data transmission. However, optical routing is limited in PICs composed of only one or a few stacked planes. Further, coupling losses must be low in deployed systems. Previously, we developed the subsurface controllable refractive index via beam exposure (SCRIBE) technique to write accurate 3D gradient refractive index (GRIN) profiles within a mesoporous silica scaffold. Here, we apply SCRIBE to fabricate low loss, broadband, polarization insensitive, fiber-coupled, single-mode volumetric interconnects that include waveguides traversing arbitrary 3D paths. By seamlessly integrating mode-matching subsurface lenses and GRIN waveguide tapers, calibrating for positional writing errors, implementing multipass exposure, automating alignment, and switching to antireflection coated fibers, we reduced the insertion loss for a fiber-PIC-fiber interconnect from 50 to 2.14 dB, or 1.47 dB, excluding the fiber array’s loss. Further, we establish an upper bound of 0.45 dB loss per coupler. We report quality factors of 27,000 and 77,000 and bending losses of 6 and 3 dB/cm for 15 and 30 µm radii microrings, respectively. We also demonstrate Bézier escalators, polarization-rotating and polarization-splitting interconnects, and a seven-channel 25 µm pitch volumetric interconnect. The SCRIBE platform presents a clear path toward realizing 3D PICs with unique functionality.","PeriodicalId":19515,"journal":{"name":"Optica","volume":"209 1","pages":""},"PeriodicalIF":10.4,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Traditional refrigeration is driven either by external forces or by the information-feedback mechanism. Surprisingly, quantum measurement and collapse, typically viewed as detrimental, can also power a quantum cooling engine without requiring any feedback mechanism. In this work, we perform a proof-of-principle demonstration of quantum measurement cooling (QMC) powered by entangled measurements using a highly controllable linear optical simulator. The simulator can simulate qubits with different energy-level spacings and their thermalizing processes at different temperatures, and also allows for arbitrary projections of two qubits at different energy levels. We show the effect of changes in energy levels and measurement bases on the cooling process and demonstrate the robustness of QMC. These results reveal the special role of entangled measurements in quantum thermodynamics, indicate that quantum measurement is not always detrimental but can be a valuable thermodynamic resource. Our setup also offers a highly controllable simulation platform for multiqubit quantum engines.
{"title":"Optical simulation of a quantum cooling engine powered by entangled measurements","authors":"Ning-Ning Wang, Huan Cao, Chao Zhang, Xiao-Ye Xu, Bi-Heng Liu, Yun-Feng Huang, Chuan-Feng Li, Guang-Can Guo","doi":"10.1364/optica.521222","DOIUrl":"https://doi.org/10.1364/optica.521222","url":null,"abstract":"Traditional refrigeration is driven either by external forces or by the information-feedback mechanism. Surprisingly, quantum measurement and collapse, typically viewed as detrimental, can also power a quantum cooling engine without requiring any feedback mechanism. In this work, we perform a proof-of-principle demonstration of quantum measurement cooling (QMC) powered by entangled measurements using a highly controllable linear optical simulator. The simulator can simulate qubits with different energy-level spacings and their thermalizing processes at different temperatures, and also allows for arbitrary projections of two qubits at different energy levels. We show the effect of changes in energy levels and measurement bases on the cooling process and demonstrate the robustness of QMC. These results reveal the special role of entangled measurements in quantum thermodynamics, indicate that quantum measurement is not always detrimental but can be a valuable thermodynamic resource. Our setup also offers a highly controllable simulation platform for multiqubit quantum engines.","PeriodicalId":19515,"journal":{"name":"Optica","volume":"30 1","pages":""},"PeriodicalIF":10.4,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pound–Drever–Hall (PDH) laser frequency stabilization is a powerful technique widely used for building narrow linewidth lasers. This technique is, however, ineffective in suppressing high-frequency (>100kHz) laser phase noise detrimental for many applications. Here, we introduce an effective method that can greatly enhance its high-frequency performance. The idea is to recycle the residual PDH signal of a laser locked to a cavity by feedforwarding it directly to the laser output field after a delay fiber. Using this straightforward method, we demonstrate a phase noise suppression capability about four orders of magnitude better than just using the usual PDH feedback for noise around a few MHz. We further find that this method exhibits noise suppression performance equivalent to cavity filtering. This method holds great promise for applications demanding highly stable lasers with diminished phase noise up to tens of MHz (e.g., precise and high-speed control of atomic and molecular quantum states).
{"title":"Pound–Drever–Hall feedforward: laser phase noise suppression beyond feedback","authors":"Yu-Xin Chao, Zhen-Xing Hua, Xin-Hui Liang, Zong-Pei Yue, Li You, Meng Khoon Tey","doi":"10.1364/optica.516838","DOIUrl":"https://doi.org/10.1364/optica.516838","url":null,"abstract":"Pound–Drever–Hall (PDH) laser frequency stabilization is a powerful technique widely used for building narrow linewidth lasers. This technique is, however, ineffective in suppressing high-frequency (>100kHz) laser phase noise detrimental for many applications. Here, we introduce an effective method that can greatly enhance its high-frequency performance. The idea is to recycle the residual PDH signal of a laser locked to a cavity by feedforwarding it directly to the laser output field after a delay fiber. Using this straightforward method, we demonstrate a phase noise suppression capability about four orders of magnitude better than just using the usual PDH feedback for noise around a few MHz. We further find that this method exhibits noise suppression performance equivalent to cavity filtering. This method holds great promise for applications demanding highly stable lasers with diminished phase noise up to tens of MHz (e.g., precise and high-speed control of atomic and molecular quantum states).","PeriodicalId":19515,"journal":{"name":"Optica","volume":"147 1","pages":""},"PeriodicalIF":10.4,"publicationDate":"2024-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Maodong Gao, Zhiquan Yuan, Yan Yu, Warren Jin, Qing-Xin Ji, Jinhao Ge, Avi Feshali, Mario Paniccia, John E. Bowers, Kerry J. Vahala
Kelly sidebands are a special type of dispersive wave that appear in mode-locked systems and they have recently been observed by pulsed excitation in integrated microcombs. Here, Kelly sidebands are generated by continuous-wave excitation in a partially coupled racetrack-resonator microcomb. The coupled-racetrack system supports two optical bands so that, in contrast to earlier studies, the soliton and Kelly sideband reside in distinct bands. The resulting interband excitation of the Kelly sidebands relaxes power requirements and continuous-wave sideband excitation is demonstrated. Tuning of sideband spectral position under pulsed excitation is also studied. Numerical simulation and the experiment show that the sidebands rely upon symmetry breaking caused by partial coupling of the two-ring system. More generally, multiband systems provide a new way to engineer Kelly sidebands for spectral broadening of microcombs.
{"title":"Observation of interband Kelly sidebands in coupled-ring soliton microcombs","authors":"Maodong Gao, Zhiquan Yuan, Yan Yu, Warren Jin, Qing-Xin Ji, Jinhao Ge, Avi Feshali, Mario Paniccia, John E. Bowers, Kerry J. Vahala","doi":"10.1364/optica.524074","DOIUrl":"https://doi.org/10.1364/optica.524074","url":null,"abstract":"Kelly sidebands are a special type of dispersive wave that appear in mode-locked systems and they have recently been observed by pulsed excitation in integrated microcombs. Here, Kelly sidebands are generated by continuous-wave excitation in a partially coupled racetrack-resonator microcomb. The coupled-racetrack system supports two optical bands so that, in contrast to earlier studies, the soliton and Kelly sideband reside in distinct bands. The resulting interband excitation of the Kelly sidebands relaxes power requirements and continuous-wave sideband excitation is demonstrated. Tuning of sideband spectral position under pulsed excitation is also studied. Numerical simulation and the experiment show that the sidebands rely upon symmetry breaking caused by partial coupling of the two-ring system. More generally, multiband systems provide a new way to engineer Kelly sidebands for spectral broadening of microcombs.","PeriodicalId":19515,"journal":{"name":"Optica","volume":"50 1","pages":""},"PeriodicalIF":10.4,"publicationDate":"2024-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hao-Tao Zhu, Yizhi Huang, Wen-Xin Pan, Chao-Wu Zhou, Jianjun Tang, Hong He, Ming Cheng, Xiandu Jin, Mi Zou, Shibiao Tang, Xiongfeng Ma, Teng-Yun Chen, Jian-Wei Pan
Quantum key distribution is a cornerstone of quantum technology, offering information-theoretical secure keys for remote parties. With many quantum communication networks established globally, the mode-pairing protocol stands out for its efficacy over inter-city distances using simple setups, emerging as a promising solution. In this study, we employ the mode-pairing scheme into existing inter-city fiber links, conducting field tests across distances ranging from tens to about a hundred kilometers. Our system achieves a key rate of 1.217 kbit/s in a 195.85 km symmetric link and 3.089 kbit/s in a 127.92 km asymmetric link without global phase locking. The results demonstrate that the mode-pairing protocol can achieve key rates comparable to those of a single quantum link between two trusted nodes on the Beijing-Shanghai backbone line, effectively reducing the need for half of the trusted nodes. These field tests confirm the mode-pairing scheme’s adaptability, efficiency, and practicality, positioning it as a highly suitable protocol for quantum networks.
{"title":"Field test of mode-pairing quantum key distribution","authors":"Hao-Tao Zhu, Yizhi Huang, Wen-Xin Pan, Chao-Wu Zhou, Jianjun Tang, Hong He, Ming Cheng, Xiandu Jin, Mi Zou, Shibiao Tang, Xiongfeng Ma, Teng-Yun Chen, Jian-Wei Pan","doi":"10.1364/optica.520697","DOIUrl":"https://doi.org/10.1364/optica.520697","url":null,"abstract":"Quantum key distribution is a cornerstone of quantum technology, offering information-theoretical secure keys for remote parties. With many quantum communication networks established globally, the mode-pairing protocol stands out for its efficacy over inter-city distances using simple setups, emerging as a promising solution. In this study, we employ the mode-pairing scheme into existing inter-city fiber links, conducting field tests across distances ranging from tens to about a hundred kilometers. Our system achieves a key rate of 1.217 kbit/s in a 195.85 km symmetric link and 3.089 kbit/s in a 127.92 km asymmetric link without global phase locking. The results demonstrate that the mode-pairing protocol can achieve key rates comparable to those of a single quantum link between two trusted nodes on the Beijing-Shanghai backbone line, effectively reducing the need for half of the trusted nodes. These field tests confirm the mode-pairing scheme’s adaptability, efficiency, and practicality, positioning it as a highly suitable protocol for quantum networks.","PeriodicalId":19515,"journal":{"name":"Optica","volume":"295 1","pages":""},"PeriodicalIF":10.4,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yangyang Liu, Shima Gholam-Mirzaei, Dipendra Khatri, Tran-Chau Truong, Troie D. Journigan, Christian Cabello, Christopher Lantigua, André Staudte, Paul B. Corkum, Michael Chini
Accompanied by the rapid development of ultrafast laser platforms in recent decades, the spatiotemporal manipulation of ultrashort laser pulses has attracted much attention due to the potential for cutting-edge applications of structured light, including optical tweezers, optical communications, super-resolution imaging, time-resolved spectroscopy in molecules and quantum materials, and strong-field physics. Today, techniques capable of characterizing the full spatial, temporal, and polarization state properties of structured light are strongly desired. Here, we demonstrate a technique, termed 3D TIPTOE, for characterizing structured mid-infrared waveforms, which uses only a two-dimensional silicon-based image sensor as both the detector and the nonlinear medium. By combining the advantages of the sub-cycle time resolution afforded by nonlinear excitation and the spatial resolution inherent to the two-dimensional sensor, the 3D TIPTOE technique allows full characterization of structured electric fields, significantly reducing the complexity of detection compared to other techniques. The validity of the technique is established by measuring both few-cycle Bessel–Gaussian pulses and radially polarized femtosecond vector beams.
{"title":"Field-resolved space–time characterization of few-cycle structured light pulses","authors":"Yangyang Liu, Shima Gholam-Mirzaei, Dipendra Khatri, Tran-Chau Truong, Troie D. Journigan, Christian Cabello, Christopher Lantigua, André Staudte, Paul B. Corkum, Michael Chini","doi":"10.1364/optica.521764","DOIUrl":"https://doi.org/10.1364/optica.521764","url":null,"abstract":"Accompanied by the rapid development of ultrafast laser platforms in recent decades, the spatiotemporal manipulation of ultrashort laser pulses has attracted much attention due to the potential for cutting-edge applications of structured light, including optical tweezers, optical communications, super-resolution imaging, time-resolved spectroscopy in molecules and quantum materials, and strong-field physics. Today, techniques capable of characterizing the full spatial, temporal, and polarization state properties of structured light are strongly desired. Here, we demonstrate a technique, termed 3D TIPTOE, for characterizing structured mid-infrared waveforms, which uses only a two-dimensional silicon-based image sensor as both the detector and the nonlinear medium. By combining the advantages of the sub-cycle time resolution afforded by nonlinear excitation and the spatial resolution inherent to the two-dimensional sensor, the 3D TIPTOE technique allows full characterization of structured electric fields, significantly reducing the complexity of detection compared to other techniques. The validity of the technique is established by measuring both few-cycle Bessel–Gaussian pulses and radially polarized femtosecond vector beams.","PeriodicalId":19515,"journal":{"name":"Optica","volume":"74 1","pages":""},"PeriodicalIF":10.4,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Traditional fluorescence microscopy is constrained by inherent trade-offs among resolution, field of view, and system complexity. To navigate these challenges, we introduce a simple and low-cost computational multi-aperture miniature microscope, utilizing a microlens array for single-shot wide-field, high-resolution imaging. Addressing the challenges posed by extensive view multiplexing and non-local, shift-variant aberrations in this device, we present SV-FourierNet, a multi-channel Fourier neural network. SV-FourierNet facilitates high-resolution image reconstruction across the entire imaging field through its learned global receptive field. We establish a close relationship between the physical spatially varying point-spread functions and the network’s learned effective receptive field. This ensures that SV-FourierNet has effectively encapsulated the spatially varying aberrations in our system and learned a physically meaningful function for image reconstruction. Training of SV-FourierNet is conducted entirely on a physics-based simulator. We showcase wide-field, high-resolution video reconstructions on colonies of freely moving C. elegans and imaging of a mouse brain section. Our computational multi-aperture miniature microscope, augmented with SV-FourierNet, represents a major advancement in computational microscopy and may find broad applications in biomedical research and other fields requiring compact microscopy solutions.
{"title":"Wide-field, high-resolution reconstruction in computational multi-aperture miniscope using a Fourier neural network","authors":"Qianwan Yang, Ruipeng Guo, Guorong Hu, Yujia Xue, Yunzhe Li, Lei Tian","doi":"10.1364/optica.523636","DOIUrl":"https://doi.org/10.1364/optica.523636","url":null,"abstract":"Traditional fluorescence microscopy is constrained by inherent trade-offs among resolution, field of view, and system complexity. To navigate these challenges, we introduce a simple and low-cost computational multi-aperture miniature microscope, utilizing a microlens array for single-shot wide-field, high-resolution imaging. Addressing the challenges posed by extensive view multiplexing and non-local, shift-variant aberrations in this device, we present SV-FourierNet, a multi-channel Fourier neural network. SV-FourierNet facilitates high-resolution image reconstruction across the entire imaging field through its learned global receptive field. We establish a close relationship between the physical spatially varying point-spread functions and the network’s learned effective receptive field. This ensures that SV-FourierNet has effectively encapsulated the spatially varying aberrations in our system and learned a physically meaningful function for image reconstruction. Training of SV-FourierNet is conducted entirely on a physics-based simulator. We showcase wide-field, high-resolution video reconstructions on colonies of freely moving <jats:italic toggle=\"yes\">C. elegans</jats:italic> and imaging of a mouse brain section. Our computational multi-aperture miniature microscope, augmented with SV-FourierNet, represents a major advancement in computational microscopy and may find broad applications in biomedical research and other fields requiring compact microscopy solutions.","PeriodicalId":19515,"journal":{"name":"Optica","volume":"51 1","pages":""},"PeriodicalIF":10.4,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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