Microring resonators(MRRs)are extensively utilized in photonic chips for generating quantum light sources and enabling high-efficiency nonlinear frequency conversion.However,conventional microrings are typically optim...Microring resonators(MRRs)are extensively utilized in photonic chips for generating quantum light sources and enabling high-efficiency nonlinear frequency conversion.However,conventional microrings are typically optimized for a single specific function,limiting their versatility in multifunctional applications.In this work,we propose a reconfigurable microring resonator architecture designed to accommodate diverse application requirements.By integrating a cascaded Mach–Zehnder interferometer(MZI)as the microring coupler,the design enables independent control of the quality factors for pump,signal and idler photons through two tunable phase shifters.This capability allows for dynamic tuning and optimization of critical performance parameters,including photon-pair generation rate(PGR),spectral purity and single photon heralding efficiency(HE).The proposed structure is implemented on a silicon photonic chip,and experimental results exhibit a wide range of tunability for these parameters,with excellent agreement with theoretical predictions.This flexible and multi-functional design offers a promising pathway for high-performance,highly integrated on-chip quantum information processing systems.展开更多
A method based on multiple images captured under different light sources at different incident angles was developed to recognize the coal density range in this study.The innovation is that two new images were construc...A method based on multiple images captured under different light sources at different incident angles was developed to recognize the coal density range in this study.The innovation is that two new images were constructed based on images captured under four single light sources.Reconstruction image 1 was constructed by fusing greyscale versions of the original images into one image,and Reconstruction image2 was constructed based on the differences between the images captured under the different light sources.Subsequently,the four original images and two reconstructed images were input into the convolutional neural network AlexNet to recognize the density range in three cases:-1.5(clean coal) and+1.5 g/cm^(3)(non-clean coal);-1.8(non-gangue) and+1.8 g/cm^(3)(gangue);-1.5(clean coal),1.5-1.8(middlings),and+1.8 g/cm^(3)(gangue).The results show the following:(1) The reconstructed images,especially Reconstruction image 2,can effectively improve the recognition accuracy for the coal density range compared with images captured under single light source.(2) The recognition accuracies for gangue and non-gangue,clean coal and non-clean coal,and clean coal,middlings,and gangue reached88.44%,86.72% and 77.08%,respectively.(3) The recognition accuracy increases as the density moves further away from the boundary density.展开更多
We tested 288 pieces of the polished cabochon jadeite-jade with high quality green and smooth surfaces using the colorimeter Color i5 based on the CIE 1976 L＊a＊b＊ uniform color space. The color changes after altern...We tested 288 pieces of the polished cabochon jadeite-jade with high quality green and smooth surfaces using the colorimeter Color i5 based on the CIE 1976 L＊a＊b＊ uniform color space. The color changes after alternating three CIE standard light sources D65, A and CWF were compared, and the degree of metamerism was evaluated. The results show that the CIE standard light sources D65, A and CWF increase the chroma of green and turn bluish green into vivid green, which are similar or to nearly colorless and transparent glass-like samples with fine textures. When the three light sources were individually alternated, the lightness of the jadeite-jades showed little change, but the tone changed significantly. Metamerism occurred only in 3 pairs among the 16 samples that were selected by cluster analysis for quality, and the metamerism colors were highly consistent of L＊D65∈（43.47, 46.75）, C＊D65∈（65.20, 68.80） and ho＊D65∈（138.10, 140.23）. We can conclude that the jadeite-jade green gradually turns to blue when the color temperature of the light source increases. But when considering both the light sources and the samples, D65 is more suitable to be the light source of jadeite-jade green when compared with the light sources CWF and A. Compared with the CIE standard green and high chroma green, high-quality jadeite-jade green has a slight yellow tone, low lightness and high chroma. The special metamerism index decreased to 1 when the light source alternated among D65, A and CWF. Therefore, the color of jadeite-jade green might be slightly influenced by alternating of the light sources.展开更多
With the epidemic of the coronavirus disease(COVID-19) infection, AlGaN-based ultraviolet-C light emitting diodes(UVC-LEDs) have attracted widespread attention for their sterilization application. However, the sterili...With the epidemic of the coronavirus disease(COVID-19) infection, AlGaN-based ultraviolet-C light emitting diodes(UVC-LEDs) have attracted widespread attention for their sterilization application. However, the sterilization characters of high power integrated light sources(ILSs) haven’t been widely investigated before utilizing in public sanitary security. In this work,by integrating up to 195 UVC-LED chips, high power UVC-LED ILSs with a light output power(LOP) of 1.88 W were demonstrated. The UVC-LED ILSs were verified to have efficient and rapid sterilization capability, which have achieved more than99.9% inactivation rate of several common pathogenic microorganisms within 1 s. In addition, the corresponding air sterilization module based on them was also demonstrated to kill more than 97% of Staphylococcus albus in the air of 20 m3 confined room within 30 min. This work demonstrates excellent sterilization ability of UVC-LED ILSs with high LOP, revealing great potential of UVC-LEDs in sterilization applications in the future.展开更多
Quantum key distribution(QKD)guarantees informationtheoretic security through the fundamental principles of quantum mechanics.As its matures,QKD networks have achieved long-distance deployment,showing significant adva...Quantum key distribution(QKD)guarantees informationtheoretic security through the fundamental principles of quantum mechanics.As its matures,QKD networks have achieved long-distance deployment,showing significant advancements in practical quantum-security communication infrastructure[1].When transitioning to large scale quantum communication networks with complicated topologies,conventional paradigms,which are based on point-to-point QKD links connected by trusted nodes,face technical challenges on achieving scalability and optimizing resource allocation.Quantum entanglements are important resources for quantum networks.展开更多
The rapid advancement of photonic integrated circuits(PICs)has presented a promising solution to meet future demands for faster data transmission,broader bandwidth,and lower power consumption.However,the indirect band...The rapid advancement of photonic integrated circuits(PICs)has presented a promising solution to meet future demands for faster data transmission,broader bandwidth,and lower power consumption.However,the indirect bandgap of silicon presents challenges in achieving optical gain,necessitating the integration of III-V materials through complex and costly bonding or epitaxial techniques.In this context,colloidal quantum dots(CQDs)have emerged as a viable alternative for on-chip light sources due to their unique properties,including cost-effective synthesis,high photoluminescence quantum yield,precisely tunable emission wavelengths across visible to near-infrared,and excellent solution processability.These distinct advantages position CQDs as promising components for next-generation optoelectronic devices,fueling advancements in fields such as telecommunications,sensing,and display technologies.In this review,we systematically examine the structural evolution of CQDs aiming at luminescent property enhancement and explore their integration with various photonic platforms.Key applications are discussed,focusing on waveguide-coupled CQD light-emitting diodes and lasers,metasurface-integrated CQD lasers,and cavity-coupled CQD single-photon sources.Additionally,this review presents recent efforts in promoting electrically pumped CQD lasers,highlighting the potential of CQD light sources to revolutionize on-chip photonic systems.Finally,we present prospects for further development of CQD-based on-chip light sources,emphasizing their role in the future of integrated photonics.展开更多
The quasi-monochromatic,continuously energy-tunable,and high-brightness gamma rays that are produced by an inverse Compton scattering(ICS)light source provide an ideal probe for gamma-ray imaging.However,owing to the ...The quasi-monochromatic,continuously energy-tunable,and high-brightness gamma rays that are produced by an inverse Compton scattering(ICS)light source provide an ideal probe for gamma-ray imaging.However,owing to the influence of the intrinsic energy-angle correlation spectrum of this type of light source,monochromatic computed tomography(CT),especially in the gamma-ray energy region,can only be realized in a low-efficiency manner,similar to first-generation CT.A dual-energy scan scheme with a large imaging field of view(FOV)was developed in this study to improve the imaging efficiency.The effectiveness of this scheme was demonstrated based on the beam parameters of a typical ICS light source using Monte Carlo simulations.By leveraging the principle of basis material decomposition,the influence of the energyangle correlation spectrum on CT reconstruction was corrected,and a monochromatic CT image of the imaging object was accurately reconstructed.Furthermore,the electron density and effective atomic number of the imaging object could be obtained simultaneously.展开更多
To fully utilize the resources provided by optical fiber networks,a cross-band quantum light source generating photon pairs,where one photon in a pair is at C band and the other is at O band,is proposed in this work.T...To fully utilize the resources provided by optical fiber networks,a cross-band quantum light source generating photon pairs,where one photon in a pair is at C band and the other is at O band,is proposed in this work.This source is based on spontaneous four-wave mixing(SFWM)in a piece of shallow-ridge silicon waveguide.Theoretical analysis shows that the waveguide dispersion could be tailored by adjusting the ridge width,enabling broadband photon pair generation by SFWM across C band and O band.The spontaneous Raman scattering(SpRS)in silicon waveguides is also investigated experimentally.It shows that there are two regions in the spectrum of generated photons from SpRS,which could be used to achieve cross-band photon pair generation.A chip of shallow-ridge silicon waveguide samples with different ridge widths has been fabricated,through which cross-band photon pair generation is demonstrated experimentally.The experimental results show that the source can be achieved using dispersion-optimized shallow-ridge silicon waveguides.This cross-band quantum light source provides a way to develop new fiber-based quantum communication functions utilizing both C band and O band and extends applications of quantum networks.展开更多
Serving as the electrical to optical converter,the on-chip silicon light source is an indispensable component of silicon photonic technologies and has long been pursued.Here,we briefly review the history and recent pr...Serving as the electrical to optical converter,the on-chip silicon light source is an indispensable component of silicon photonic technologies and has long been pursued.Here,we briefly review the history and recent progress of a few promising contenders for on-chip light sources in terms of operating wavelength,pump condition,power consumption,and fabrication process.Additionally,the performance of each contender is also assessed with respect to thermal stability,which is a crucial parameter to consider in complex optoelectronic integrated circuits(OEICs)and optical interconnections.Currently,III-V-based silicon(Si)lasers formed via bonding techniques demonstrate the best performance and display the best opportunity for commercial usage in the near future.However,in the long term,direct hetero-epitaxial growth of III–V materials on Si seems more promising for low-cost,high-yield fabrication.The demonstration of high-performance quantum dot(QD)lasers monolithically grown on Si strongly forecasts its feasibility and enormous potential for on-chip lasers.The superior temperature-insensitive characteristics of the QD laser promote this design in large-scale high-density OEICs.The Germanium(Ge)-on-Si laser is also competitive for large-scale monolithic integration in the future.Compared with a III-V-based Si laser,the biggest potential advantage of a Ge-on-Si laser lies in its material and processing compatibility with Si technology.Additionally,the versatility of Ge facilitates photon emission,modulation,and detection simultaneously with a simple process complexity and low cost.展开更多
A method for generating multi-wavelength light source is theoretically investigated by optical parametric oscillation （OPO） in aperiodic optical superlattice （AOS）. The effects of domain errors caused by the ro om...A method for generating multi-wavelength light source is theoretically investigated by optical parametric oscillation （OPO） in aperiodic optical superlattice （AOS）. The effects of domain errors caused by the ro om-temperature electric poling process are checked. The relationship between the linewidth and the block length is also discussed.展开更多
Recent advances in quantum dots （QDs） for classical and non-classical light sources are presented. We have established metal organic chemical vapor deposition （MOCVD） technology for InAs-based QD lasers at 1.3 μm...Recent advances in quantum dots （QDs） for classical and non-classical light sources are presented. We have established metal organic chemical vapor deposition （MOCVD） technology for InAs-based QD lasers at 1.3 μm and achieved ultralow threshold in QD lasers with photonic crystal （PhC） nanocavity. In addition, single photon emitters at 1.55 μm, GaN-based single photon sources operating at 200 K, and high-Q PhC nanocavity have been demonstrated.展开更多
Using a low coherence interferometry （LCI） model, a comparison of broadband single-Gaussian and multi-Gaussian light sources has been undertaken. For single-Gaussian sources, the axial resolution improves with the s...Using a low coherence interferometry （LCI） model, a comparison of broadband single-Gaussian and multi-Gaussian light sources has been undertaken. For single-Gaussian sources, the axial resolution improves with the source bandwidth, confirming the coherence length relation that the resolution for single Gaussian sources improves with increasing spectral bandwidth. However, narrow bandwidth light sources result in interferograms with overlapping strata peaks and the loss of individual strata information. For multiple-Gaussian sources with the same bandwidth, spectral side lobes increase, reducing A-scan reliability to show accurate layer information without eliminating the side lobes. The simulations show the conditions needed for the resolution of strata information for broadband light sources using both single and multiple Gaussian models. The potential to use the model to study optical coherence tomography （OCT） light sources including super luminescent diodes （SLDs）, as reviewed in this paper, as well as optical delay lines and sample structures could better characterize these LCI and OCT elements. Forecasting misinformation in the interferogram may allow preliminary corrections. With improvement to the LCI-OCT model, more applications are envisaged.展开更多
In this letter, two kinds of continuous wavelength-tunable light sources are achieved and investigated experimentally using a self-seeding reflective semiconductor optical amplifier （RSOA）. Over 40 single mode wavel...In this letter, two kinds of continuous wavelength-tunable light sources are achieved and investigated experimentally using a self-seeding reflective semiconductor optical amplifier （RSOA）. Over 40 single mode wavelengths with 100 GHz spacing are generated by setting the parameters of the wavelength selective switch. The peak power of each wavelength reaches over 0.2 dBm with the signal-to-noise ratio （SNR） 〉 35 dB. The proposed schemes are appropriate for multi-wavelength-tunable light sources; the maximum number of wavelengths generated can reach to 4.展开更多
Free-electron light sources feature extraordinary luminosity,directionality,and coherence,which has enabled significant scientific progress in fields including physics,chemistry,and biology.The next generation of ligh...Free-electron light sources feature extraordinary luminosity,directionality,and coherence,which has enabled significant scientific progress in fields including physics,chemistry,and biology.The next generation of light sources has aimed at compact radiation sources driven by free electrons,with the advantages of reduction in both space and cost.With the rapid development of ultra-intense and ultrashort lasers,great effort has been devoted to the quest for compact free-electron lasers(FELs).This review focuses on the current efforts and advancements in the development of compact FELs,with a particular emphasis on two notable paths:the development of compact accelerators and the construction of micro undulators based on innovative materials/structures or optical modulation of electrons.In addition,the physical essence of inverse Compton scattering is discussed,which offers remarkable capability to develop an optical undulator with a spatial period that matches the optical wavelength.Recent scientific developments and future directions for miniaturized and integrated free-electron coherent light sources are also reviewed.In the future,the prospect of generating ultrashort electron pulses will provide fascinating means of producing superradiant radiation,promising high brilliance and coherence even on a micro scale using optical micro undulators.展开更多
Micro light sources are crucial tools for studying the interactions between light and matter at the micro/nanoscale,encompassing diverse applications across multiple disciplines.Despite numerous studies on reducing th...Micro light sources are crucial tools for studying the interactions between light and matter at the micro/nanoscale,encompassing diverse applications across multiple disciplines.Despite numerous studies on reducing the size of micro light sources and enhancing optical resolution,the efficient and simple fabrication of ultra-high-resolution micro light sources remains challenging due to its reliance on precise micro-nano processing technology and advanced processing equipment.In this study,a simple approach for the efficient fabrication of submicron light sources is proposed,namely shadow-assisted sidewall emission(SASE)technology.The SASE utilizes the widely adopted UV photolithography process,employing metal shadow modulation to precisely control the emission of light from polymer sidewalls,thereby obtaining photoluminescent light sources with submicron line widths.The SASE eliminates the need for complex and cumbersome manufacturing procedures.The effects of process parameters,including exposure dose,development time,and metal film thickness,on the linewidth of sources are investigated on detail.It is successfully demonstrated red,green,and blue submicron light sources.Finally,their potential application in the field of optical anti-counterfeiting is also demonstrated.We believe that the SASE proposed in this work provides a novel approach for the preparation and application of micro light sources.展开更多
Red and blue light illumination has been reported to significantly affect plantlet growth.Potato is an important food and feed crop in the world and potato plantlet cultured in vitro plays an important role in potato ...Red and blue light illumination has been reported to significantly affect plantlet growth.Potato is an important food and feed crop in the world and potato plantlet cultured in vitro plays an important role in potato production.However,few studies have documented the effects of red and blue light on the growth of potato plantlets revealed at the transcriptome level.The objective of this study was to determine the growth and physiological responses of potato plantlets cultured in vitro under monochromatic red(RR),monochromatic blue(BB)as well as combined red and blue(RB)LEDs using the RNA-Seq technique.In total,3150 and 814 differentially expressed genes(DEGs)were detected in potato plantlets under RR and BB,respectively,compared to RB(used as control).Compared to the control,the DEGs enriched in"photosynthesis"and"photosynthesis-antenna proteins"metabolic pathways were up-regulated and down-regulated by BB and RR,respectively,which might be responsible for the increases and decreases of maximum quantum yield(F_(v)/F_(m)),photochemical quantum yield(φ_(PSII)),photochemical quenching(q_(P))and electron transfer rate(ETR)in BB and RR,respectively.Potato plantlets exhibited dwarfed stems and extended leaves under BB,whereas elongated stems and small leaves were induced under RR.These dramatically altered plantlet phenotypes were associated with variable levels of endogenous plant hormones gibberellin(GAs),indoleacetic acid(IAA)and cytokinins(CKs),as assessed in stems and leaves of potato plantlets.In addition,monochromatic red and blue LEDs trigged the opposite expression profiles of DEGs identified in the"plant hormone signal transduction"metabolic pathway,which were closely related to the endogenous plant hormone levels in potato plantlets.Our results provide insights into the responses of potato plantlets cultured in vitro to red and blue LEDs at the transcriptomic level and may contribute to improvements in the micro-propagation of potato plantlets cultured in vitro from the light spectrum aspect.展开更多
Determination of light absorption distribution in the prostate tissue irradiated by diffusing light source is important for the treatment planning.In this paper,a three-dimensional(3D)optical model of human prostate i...Determination of light absorption distribution in the prostate tissue irradiated by diffusing light source is important for the treatment planning.In this paper,a three-dimensional(3D)optical model of human prostate is developed,and the light absorption distribution in the prostate tissue is estimated by Monte Carlo simulation method.Light distribution patterns including 3D distributions in the tissue model irradiated by two diffusing light sources are obtained and compared.Also,the impacts of length and energy of cylinder diffusing light source on the irradiance volume are demonstrated.Those results will be significant for the nondestructive qualitative assessments of photodosimetry in biomedical phototherapy.展开更多
When a structure material is damaged by impact events, the reliability and lifetime of the material will be severely af- fected. So impact location is considered as the prime approach for structural health and damage ...When a structure material is damaged by impact events, the reliability and lifetime of the material will be severely af- fected. So impact location is considered as the prime approach for structural health and damage monitoring. In this study, a novel fiber Bragg grating （FBG） impact location system based on broadband light source is designed, aiming at the shortcoming of existing location systems based on FBG. An improved localization algorithm based on the time difference of arrival （TDoA） is proposed for impact location. According to this algorithm, the impact position can be accurately predicted without wave velocity. Impact planar location experiments are carried out for verification of the FBG impact location system and algorithm on a 400 mmx400 mmx3 mm aluminum alloy plate. The resulted locating error shows high precision and good stability of the proposed system.展开更多
On the one hand,existing measurement device independent quantum key distribution(MDI-QKD)protocols have usually adopted single photon source(SPS)and weak coherent photon(WCP),however,these protocols have suffered from...On the one hand,existing measurement device independent quantum key distribution(MDI-QKD)protocols have usually adopted single photon source(SPS)and weak coherent photon(WCP),however,these protocols have suffered from multi-photon problem brought from photon splitter number attacks.On the other hand,the orbital angular momentum(OAM)-MDI-QKD protocol does not need to compare and adjust the reference frame,solving the dependency of the base in the MDI-QKD protocol.Given that,we propose the OAM-MDI-QKD protocol based on the parametric light sources which mainly include single-photon-added-coherent(SPACS)and heralded single-photon sources(HSPS).Due to the stability of OAM and the participation of parametric light sources,the performance of MDI-QKD protocol gradually approaches the ideal situation.Numerical simulation shows that compared with WCP scheme,HSPS and SPACS schemes have increased the maximum secure transmission distance by 30 km and 40 km respectively.展开更多
Non-uniformity of light sources is one of the inevitable error factors causing poor shape recoveryaccuracy of photometric stereo methods under close-range lighting with quasi point lights. Semi-calibrated photometrics...Non-uniformity of light sources is one of the inevitable error factors causing poor shape recoveryaccuracy of photometric stereo methods under close-range lighting with quasi point lights. Semi-calibrated photometricstereo methods are required to avoid repeated, tedious and impractical photometric calibration. In thispaper, two simple, concise but effective mesh-based semi-calibrated photometric stereo methods are proposed.The proposed methods extend the traditional mesh-based photometric stereo methods and further allow joint andaccurate estimation of normals and non-uniform light intensities by alternatively updating normals, depth mapsand intensities. Extensive experiments are conducted to validate the effectiveness and robustness of the proposedalgorithms. Even under extremely severe non-uniform lighting, the proposed methods can still suppress the errorand improve the shape recovery accuracy by up to 65.6% in real-world experiments.展开更多
基金Project supported by the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301500)the National Natural Science Foundation of China(Grant No.62105366)。
文摘Microring resonators(MRRs)are extensively utilized in photonic chips for generating quantum light sources and enabling high-efficiency nonlinear frequency conversion.However,conventional microrings are typically optimized for a single specific function,limiting their versatility in multifunctional applications.In this work,we propose a reconfigurable microring resonator architecture designed to accommodate diverse application requirements.By integrating a cascaded Mach–Zehnder interferometer(MZI)as the microring coupler,the design enables independent control of the quality factors for pump,signal and idler photons through two tunable phase shifters.This capability allows for dynamic tuning and optimization of critical performance parameters,including photon-pair generation rate(PGR),spectral purity and single photon heralding efficiency(HE).The proposed structure is implemented on a silicon photonic chip,and experimental results exhibit a wide range of tunability for these parameters,with excellent agreement with theoretical predictions.This flexible and multi-functional design offers a promising pathway for high-performance,highly integrated on-chip quantum information processing systems.
文摘A method based on multiple images captured under different light sources at different incident angles was developed to recognize the coal density range in this study.The innovation is that two new images were constructed based on images captured under four single light sources.Reconstruction image 1 was constructed by fusing greyscale versions of the original images into one image,and Reconstruction image2 was constructed based on the differences between the images captured under the different light sources.Subsequently,the four original images and two reconstructed images were input into the convolutional neural network AlexNet to recognize the density range in three cases:-1.5(clean coal) and+1.5 g/cm^(3)(non-clean coal);-1.8(non-gangue) and+1.8 g/cm^(3)(gangue);-1.5(clean coal),1.5-1.8(middlings),and+1.8 g/cm^(3)(gangue).The results show the following:(1) The reconstructed images,especially Reconstruction image 2,can effectively improve the recognition accuracy for the coal density range compared with images captured under single light source.(2) The recognition accuracies for gangue and non-gangue,clean coal and non-clean coal,and clean coal,middlings,and gangue reached88.44%,86.72% and 77.08%,respectively.(3) The recognition accuracy increases as the density moves further away from the boundary density.
基金financial support by "the Fundamental Research Funds for the Central Universities"
文摘We tested 288 pieces of the polished cabochon jadeite-jade with high quality green and smooth surfaces using the colorimeter Color i5 based on the CIE 1976 L＊a＊b＊ uniform color space. The color changes after alternating three CIE standard light sources D65, A and CWF were compared, and the degree of metamerism was evaluated. The results show that the CIE standard light sources D65, A and CWF increase the chroma of green and turn bluish green into vivid green, which are similar or to nearly colorless and transparent glass-like samples with fine textures. When the three light sources were individually alternated, the lightness of the jadeite-jades showed little change, but the tone changed significantly. Metamerism occurred only in 3 pairs among the 16 samples that were selected by cluster analysis for quality, and the metamerism colors were highly consistent of L＊D65∈（43.47, 46.75）, C＊D65∈（65.20, 68.80） and ho＊D65∈（138.10, 140.23）. We can conclude that the jadeite-jade green gradually turns to blue when the color temperature of the light source increases. But when considering both the light sources and the samples, D65 is more suitable to be the light source of jadeite-jade green when compared with the light sources CWF and A. Compared with the CIE standard green and high chroma green, high-quality jadeite-jade green has a slight yellow tone, low lightness and high chroma. The special metamerism index decreased to 1 when the light source alternated among D65, A and CWF. Therefore, the color of jadeite-jade green might be slightly influenced by alternating of the light sources.
基金supported by the Guangdong Basic and Application Basic Research Foundation of Guangdong Province (Nos. 2021A1515111149, 2021B1515120022, 2020B 010174003)。
文摘With the epidemic of the coronavirus disease(COVID-19) infection, AlGaN-based ultraviolet-C light emitting diodes(UVC-LEDs) have attracted widespread attention for their sterilization application. However, the sterilization characters of high power integrated light sources(ILSs) haven’t been widely investigated before utilizing in public sanitary security. In this work,by integrating up to 195 UVC-LED chips, high power UVC-LED ILSs with a light output power(LOP) of 1.88 W were demonstrated. The UVC-LED ILSs were verified to have efficient and rapid sterilization capability, which have achieved more than99.9% inactivation rate of several common pathogenic microorganisms within 1 s. In addition, the corresponding air sterilization module based on them was also demonstrated to kill more than 97% of Staphylococcus albus in the air of 20 m3 confined room within 30 min. This work demonstrates excellent sterilization ability of UVC-LED ILSs with high LOP, revealing great potential of UVC-LEDs in sterilization applications in the future.
文摘Quantum key distribution(QKD)guarantees informationtheoretic security through the fundamental principles of quantum mechanics.As its matures,QKD networks have achieved long-distance deployment,showing significant advancements in practical quantum-security communication infrastructure[1].When transitioning to large scale quantum communication networks with complicated topologies,conventional paradigms,which are based on point-to-point QKD links connected by trusted nodes,face technical challenges on achieving scalability and optimizing resource allocation.Quantum entanglements are important resources for quantum networks.
基金supported by the National Key Research and Development Program of China(No.2022YFB3606504)National Natural Science Foundation of China(No.62122034,No.62475171)+2 种基金Shenzhen Key Laborlatory for Advanced Quantum Dot Displays and Lighting(No.ZDSYS201707281632549)Shenzhen Stable Support Research Foundation(No.20220717215521001)High Level of Special Funds(No.G030230001,G03034K002)from Southern University of Science and Technology。
文摘The rapid advancement of photonic integrated circuits(PICs)has presented a promising solution to meet future demands for faster data transmission,broader bandwidth,and lower power consumption.However,the indirect bandgap of silicon presents challenges in achieving optical gain,necessitating the integration of III-V materials through complex and costly bonding or epitaxial techniques.In this context,colloidal quantum dots(CQDs)have emerged as a viable alternative for on-chip light sources due to their unique properties,including cost-effective synthesis,high photoluminescence quantum yield,precisely tunable emission wavelengths across visible to near-infrared,and excellent solution processability.These distinct advantages position CQDs as promising components for next-generation optoelectronic devices,fueling advancements in fields such as telecommunications,sensing,and display technologies.In this review,we systematically examine the structural evolution of CQDs aiming at luminescent property enhancement and explore their integration with various photonic platforms.Key applications are discussed,focusing on waveguide-coupled CQD light-emitting diodes and lasers,metasurface-integrated CQD lasers,and cavity-coupled CQD single-photon sources.Additionally,this review presents recent efforts in promoting electrically pumped CQD lasers,highlighting the potential of CQD light sources to revolutionize on-chip photonic systems.Finally,we present prospects for further development of CQD-based on-chip light sources,emphasizing their role in the future of integrated photonics.
基金supported by the National Natural Science Foundation of China(Nos.12375157,12027902,and 11905011)。
文摘The quasi-monochromatic,continuously energy-tunable,and high-brightness gamma rays that are produced by an inverse Compton scattering(ICS)light source provide an ideal probe for gamma-ray imaging.However,owing to the influence of the intrinsic energy-angle correlation spectrum of this type of light source,monochromatic computed tomography(CT),especially in the gamma-ray energy region,can only be realized in a low-efficiency manner,similar to first-generation CT.A dual-energy scan scheme with a large imaging field of view(FOV)was developed in this study to improve the imaging efficiency.The effectiveness of this scheme was demonstrated based on the beam parameters of a typical ICS light source using Monte Carlo simulations.By leveraging the principle of basis material decomposition,the influence of the energyangle correlation spectrum on CT reconstruction was corrected,and a monochromatic CT image of the imaging object was accurately reconstructed.Furthermore,the electron density and effective atomic number of the imaging object could be obtained simultaneously.
基金supported by the Quantum Science and Technology-National Science and Technology Major Project (Grant No.2024ZD0302502 for WZ)the National Natural Science Foundation of China(Grant No.92365210 for WZ)+1 种基金Tsinghua Initiative Scientific Research Program (for WZ)the project of Tsinghua University-Zhuhai Huafa Industrial Share Company Joint Institute for Architecture Optoelectronic Technologies (JIAOT,for YH)。
文摘To fully utilize the resources provided by optical fiber networks,a cross-band quantum light source generating photon pairs,where one photon in a pair is at C band and the other is at O band,is proposed in this work.This source is based on spontaneous four-wave mixing(SFWM)in a piece of shallow-ridge silicon waveguide.Theoretical analysis shows that the waveguide dispersion could be tailored by adjusting the ridge width,enabling broadband photon pair generation by SFWM across C band and O band.The spontaneous Raman scattering(SpRS)in silicon waveguides is also investigated experimentally.It shows that there are two regions in the spectrum of generated photons from SpRS,which could be used to achieve cross-band photon pair generation.A chip of shallow-ridge silicon waveguide samples with different ridge widths has been fabricated,through which cross-band photon pair generation is demonstrated experimentally.The experimental results show that the source can be achieved using dispersion-optimized shallow-ridge silicon waveguides.This cross-band quantum light source provides a way to develop new fiber-based quantum communication functions utilizing both C band and O band and extends applications of quantum networks.
基金This work was partially supported by the Major International Cooperation and Exchange Program of the National Natural Science Foundation of China under Grant 61120106012the Peking University 985 Startup Fund.
文摘Serving as the electrical to optical converter,the on-chip silicon light source is an indispensable component of silicon photonic technologies and has long been pursued.Here,we briefly review the history and recent progress of a few promising contenders for on-chip light sources in terms of operating wavelength,pump condition,power consumption,and fabrication process.Additionally,the performance of each contender is also assessed with respect to thermal stability,which is a crucial parameter to consider in complex optoelectronic integrated circuits(OEICs)and optical interconnections.Currently,III-V-based silicon(Si)lasers formed via bonding techniques demonstrate the best performance and display the best opportunity for commercial usage in the near future.However,in the long term,direct hetero-epitaxial growth of III–V materials on Si seems more promising for low-cost,high-yield fabrication.The demonstration of high-performance quantum dot(QD)lasers monolithically grown on Si strongly forecasts its feasibility and enormous potential for on-chip lasers.The superior temperature-insensitive characteristics of the QD laser promote this design in large-scale high-density OEICs.The Germanium(Ge)-on-Si laser is also competitive for large-scale monolithic integration in the future.Compared with a III-V-based Si laser,the biggest potential advantage of a Ge-on-Si laser lies in its material and processing compatibility with Si technology.Additionally,the versatility of Ge facilitates photon emission,modulation,and detection simultaneously with a simple process complexity and low cost.
基金This work was supported by the National Natural Science Foundation of China (No. 60477016) the Foundation for Development of Science and Technology of Shanghai (No. 04DZ14001)"Shu Guang" Project by Shanghai Municipal Education Commission.
文摘A method for generating multi-wavelength light source is theoretically investigated by optical parametric oscillation （OPO） in aperiodic optical superlattice （AOS）. The effects of domain errors caused by the ro om-temperature electric poling process are checked. The relationship between the linewidth and the block length is also discussed.
基金Special Coordination Funds for Promoting Science and Technology
文摘Recent advances in quantum dots （QDs） for classical and non-classical light sources are presented. We have established metal organic chemical vapor deposition （MOCVD） technology for InAs-based QD lasers at 1.3 μm and achieved ultralow threshold in QD lasers with photonic crystal （PhC） nanocavity. In addition, single photon emitters at 1.55 μm, GaN-based single photon sources operating at 200 K, and high-Q PhC nanocavity have been demonstrated.
文摘Using a low coherence interferometry （LCI） model, a comparison of broadband single-Gaussian and multi-Gaussian light sources has been undertaken. For single-Gaussian sources, the axial resolution improves with the source bandwidth, confirming the coherence length relation that the resolution for single Gaussian sources improves with increasing spectral bandwidth. However, narrow bandwidth light sources result in interferograms with overlapping strata peaks and the loss of individual strata information. For multiple-Gaussian sources with the same bandwidth, spectral side lobes increase, reducing A-scan reliability to show accurate layer information without eliminating the side lobes. The simulations show the conditions needed for the resolution of strata information for broadband light sources using both single and multiple Gaussian models. The potential to use the model to study optical coherence tomography （OCT） light sources including super luminescent diodes （SLDs）, as reviewed in this paper, as well as optical delay lines and sample structures could better characterize these LCI and OCT elements. Forecasting misinformation in the interferogram may allow preliminary corrections. With improvement to the LCI-OCT model, more applications are envisaged.
基金supported by the National Natural Science Foundation of China (Nos.61271216,61221001,61090393,and 60972032)the National "973" Project of China(Nos.2010CB328205,2010CB328204,and 2012CB315602)the National "863" Hi-tech Project of China
文摘In this letter, two kinds of continuous wavelength-tunable light sources are achieved and investigated experimentally using a self-seeding reflective semiconductor optical amplifier （RSOA）. Over 40 single mode wavelengths with 100 GHz spacing are generated by setting the parameters of the wavelength selective switch. The peak power of each wavelength reaches over 0.2 dBm with the signal-to-noise ratio （SNR） 〉 35 dB. The proposed schemes are appropriate for multi-wavelength-tunable light sources; the maximum number of wavelengths generated can reach to 4.
基金supported by the Shanghai Pilot Program for Basic Research-Chinese Academy of Sciences,ShanghaiBranchNational Natural Science Foundation of China(Nos.12104471,U226720057,and 62105346)+3 种基金Key Research Program of Frontier Sciences,Chinese Academy of SciencesYouth Innovation Promotion Association of Chinese Academy of SciencesCAS Project for Young Scientists in Basic Research(No.YSBRO60)Shanghai Sailing Program(No.21YF1453900).
文摘Free-electron light sources feature extraordinary luminosity,directionality,and coherence,which has enabled significant scientific progress in fields including physics,chemistry,and biology.The next generation of light sources has aimed at compact radiation sources driven by free electrons,with the advantages of reduction in both space and cost.With the rapid development of ultra-intense and ultrashort lasers,great effort has been devoted to the quest for compact free-electron lasers(FELs).This review focuses on the current efforts and advancements in the development of compact FELs,with a particular emphasis on two notable paths:the development of compact accelerators and the construction of micro undulators based on innovative materials/structures or optical modulation of electrons.In addition,the physical essence of inverse Compton scattering is discussed,which offers remarkable capability to develop an optical undulator with a spatial period that matches the optical wavelength.Recent scientific developments and future directions for miniaturized and integrated free-electron coherent light sources are also reviewed.In the future,the prospect of generating ultrashort electron pulses will provide fascinating means of producing superradiant radiation,promising high brilliance and coherence even on a micro scale using optical micro undulators.
基金supported by Natural Science Foundation of the Fujian Province,China(2024J010016)the National Key R&D Program of China(2021YFB3600400)Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Project(2020ZZ113,2021ZZ130)。
文摘Micro light sources are crucial tools for studying the interactions between light and matter at the micro/nanoscale,encompassing diverse applications across multiple disciplines.Despite numerous studies on reducing the size of micro light sources and enhancing optical resolution,the efficient and simple fabrication of ultra-high-resolution micro light sources remains challenging due to its reliance on precise micro-nano processing technology and advanced processing equipment.In this study,a simple approach for the efficient fabrication of submicron light sources is proposed,namely shadow-assisted sidewall emission(SASE)technology.The SASE utilizes the widely adopted UV photolithography process,employing metal shadow modulation to precisely control the emission of light from polymer sidewalls,thereby obtaining photoluminescent light sources with submicron line widths.The SASE eliminates the need for complex and cumbersome manufacturing procedures.The effects of process parameters,including exposure dose,development time,and metal film thickness,on the linewidth of sources are investigated on detail.It is successfully demonstrated red,green,and blue submicron light sources.Finally,their potential application in the field of optical anti-counterfeiting is also demonstrated.We believe that the SASE proposed in this work provides a novel approach for the preparation and application of micro light sources.
基金funded by the Scientific Research Fund of College of Science&Technology,Ningbo University for the Introduction of High-level Talents,China(RC190006)。
文摘Red and blue light illumination has been reported to significantly affect plantlet growth.Potato is an important food and feed crop in the world and potato plantlet cultured in vitro plays an important role in potato production.However,few studies have documented the effects of red and blue light on the growth of potato plantlets revealed at the transcriptome level.The objective of this study was to determine the growth and physiological responses of potato plantlets cultured in vitro under monochromatic red(RR),monochromatic blue(BB)as well as combined red and blue(RB)LEDs using the RNA-Seq technique.In total,3150 and 814 differentially expressed genes(DEGs)were detected in potato plantlets under RR and BB,respectively,compared to RB(used as control).Compared to the control,the DEGs enriched in"photosynthesis"and"photosynthesis-antenna proteins"metabolic pathways were up-regulated and down-regulated by BB and RR,respectively,which might be responsible for the increases and decreases of maximum quantum yield(F_(v)/F_(m)),photochemical quantum yield(φ_(PSII)),photochemical quenching(q_(P))and electron transfer rate(ETR)in BB and RR,respectively.Potato plantlets exhibited dwarfed stems and extended leaves under BB,whereas elongated stems and small leaves were induced under RR.These dramatically altered plantlet phenotypes were associated with variable levels of endogenous plant hormones gibberellin(GAs),indoleacetic acid(IAA)and cytokinins(CKs),as assessed in stems and leaves of potato plantlets.In addition,monochromatic red and blue LEDs trigged the opposite expression profiles of DEGs identified in the"plant hormone signal transduction"metabolic pathway,which were closely related to the endogenous plant hormone levels in potato plantlets.Our results provide insights into the responses of potato plantlets cultured in vitro to red and blue LEDs at the transcriptomic level and may contribute to improvements in the micro-propagation of potato plantlets cultured in vitro from the light spectrum aspect.
基金supported by the National Natural Science Foundation of China(Nos.61178089 and 81201124)the Fujian Provincial Key Program of Science and Technology(No.2011Y0019)+1 种基金the Fujian Provincial Education Science Research Project of Young Teachers(No.JA14189)the Huang Huizhen Foundation for Discipline Construction in Jimei University(No.ZB2013068)
文摘Determination of light absorption distribution in the prostate tissue irradiated by diffusing light source is important for the treatment planning.In this paper,a three-dimensional(3D)optical model of human prostate is developed,and the light absorption distribution in the prostate tissue is estimated by Monte Carlo simulation method.Light distribution patterns including 3D distributions in the tissue model irradiated by two diffusing light sources are obtained and compared.Also,the impacts of length and energy of cylinder diffusing light source on the irradiance volume are demonstrated.Those results will be significant for the nondestructive qualitative assessments of photodosimetry in biomedical phototherapy.
基金supported by the National Natural Science Foundation of China(Nos.61503218,61403233,61573226 and 61473176)the Excellent Young and Middle-Aged Scientist Award Grant of Shandong Province of China(No.BS2013DX018)the Natural Science Foundation of Shandong Province for Outstanding Young Talents(No.ZR2015JL021)
文摘When a structure material is damaged by impact events, the reliability and lifetime of the material will be severely af- fected. So impact location is considered as the prime approach for structural health and damage monitoring. In this study, a novel fiber Bragg grating （FBG） impact location system based on broadband light source is designed, aiming at the shortcoming of existing location systems based on FBG. An improved localization algorithm based on the time difference of arrival （TDoA） is proposed for impact location. According to this algorithm, the impact position can be accurately predicted without wave velocity. Impact planar location experiments are carried out for verification of the FBG impact location system and algorithm on a 400 mmx400 mmx3 mm aluminum alloy plate. The resulted locating error shows high precision and good stability of the proposed system.
基金Hong Lai has been supported by the National Natural Science Foundation of China(No.61702427)the Chongqing innovation project(No.cx2018076)+1 种基金the Fundamental Research Funds for the Central Universities(XDJK2018C048)the financial support in part by the 1000-Plan of Chongqing by Southwest University(No.SWU116007)。
文摘On the one hand,existing measurement device independent quantum key distribution(MDI-QKD)protocols have usually adopted single photon source(SPS)and weak coherent photon(WCP),however,these protocols have suffered from multi-photon problem brought from photon splitter number attacks.On the other hand,the orbital angular momentum(OAM)-MDI-QKD protocol does not need to compare and adjust the reference frame,solving the dependency of the base in the MDI-QKD protocol.Given that,we propose the OAM-MDI-QKD protocol based on the parametric light sources which mainly include single-photon-added-coherent(SPACS)and heralded single-photon sources(HSPS).Due to the stability of OAM and the participation of parametric light sources,the performance of MDI-QKD protocol gradually approaches the ideal situation.Numerical simulation shows that compared with WCP scheme,HSPS and SPACS schemes have increased the maximum secure transmission distance by 30 km and 40 km respectively.
基金the National Natural Science Foundation of China(No.61927822)。
文摘Non-uniformity of light sources is one of the inevitable error factors causing poor shape recoveryaccuracy of photometric stereo methods under close-range lighting with quasi point lights. Semi-calibrated photometricstereo methods are required to avoid repeated, tedious and impractical photometric calibration. In thispaper, two simple, concise but effective mesh-based semi-calibrated photometric stereo methods are proposed.The proposed methods extend the traditional mesh-based photometric stereo methods and further allow joint andaccurate estimation of normals and non-uniform light intensities by alternatively updating normals, depth mapsand intensities. Extensive experiments are conducted to validate the effectiveness and robustness of the proposedalgorithms. Even under extremely severe non-uniform lighting, the proposed methods can still suppress the errorand improve the shape recovery accuracy by up to 65.6% in real-world experiments.
