We demonstrate a broadband optical parametric oscillation,using a sheet cavity,via cavity phase-matching.A21.2 THz broad comb-like spectrum is achieved,with a uniform line spacing of 133.0 GHz,despite a relatively lar...We demonstrate a broadband optical parametric oscillation,using a sheet cavity,via cavity phase-matching.A21.2 THz broad comb-like spectrum is achieved,with a uniform line spacing of 133.0 GHz,despite a relatively large dispersion of 275.4 fs^(2)/mm around 1064 nm.With 22.6% high slope efficiency,and 14.9 kW peak power handling,this sheet optical parametric oscillator can be further developed for x^((2)) comb.展开更多
Fiber optofluidic laser(FOFL)integrates optical fiber microcavity and microfluidic channel and provides many unique advantages for sensing applications.FOFLs not only inherit the advantages of lasers such as high sens...Fiber optofluidic laser(FOFL)integrates optical fiber microcavity and microfluidic channel and provides many unique advantages for sensing applications.FOFLs not only inherit the advantages of lasers such as high sensitivity,high signal-to-noise ratio,and narrow linewidth,but also hold the unique features of optical fiber,including ease of integration,high repeatability,and low cost.With the development of new fiber structures and fabrication technologies,FOFLs become an important branch of optical fiber sensors,especially for application in biochemical detection.In this paper,the recent progress on FOFL is reviewed.We focuse mainly on the optical fiber resonators,gain medium,and the emerging sen sing applicatio ns.The prospects for FOFL are also discussed.We believe that the FOFL sensor provides a promising technology for biomedical analysis and environmental monitoring.展开更多
The excitation of the surface field and evanescent enhancement in the graphene have shown sensitive to the refractive index of surrounding media and potential applications in high-sensitivity biochemical sensing. In t...The excitation of the surface field and evanescent enhancement in the graphene have shown sensitive to the refractive index of surrounding media and potential applications in high-sensitivity biochemical sensing. In this paper, we investigate the graphene-coated microfiber Bragg gratings （GMFBGs） with different diameters for ammonia gas sensing. The maximum sensitivity with 6pm/ppm was achieved experimentally when the microfiber＇s diameter was about 10 μm. Moreover, by adjusting the diameter of the GMFBG, the sensing performance of the GMFBGs could be optimized. Experimental results indicated that GMFBGs with the diameter of 8μm - 12μm would show the characteristics of the high sensitivity, relative low attenuation, and large dynamic range.展开更多
Optical microcavities offer a promising platform for highly efficient light–matter interactions.Recently,the combination of microresonators and 2D materials in the nanoscale has further enriched the optoelectronics o...Optical microcavities offer a promising platform for highly efficient light–matter interactions.Recently,the combination of microresonators and 2D materials in the nanoscale has further enriched the optoelectronics of microcavity geometries,spurring broad advances including lasers,nonlinear converters,modulators,and sensors.Here,we report the concept of compact dual-laser cogeneration in a graphene-microcavity fiber,which offers a way to cancel the optical common mode noises.Driven by a single 980 nm pump,orthogonally polarized laser lines are generated in a pair of degeneracy breaking modes.The two laser lines produce a heterodyne beat note at 118.96 MHz,with frequency noise down to 200 Hz~2∕Hz at 1 MHz offset,demonstrating a linewidth of 930 Hz in vacuum.This compact device enables on-line and label-free NH_(3) gas detection with high resolution,realizing a detection limit on a single pmol/L level,and a capability to quantitatively trace gas–graphene interactions.Such a combination of graphene optoelectronics and microcavity photonics demonstrates a novel physical paradigm for microlaser control and offers a new scheme for in situ chemical sensing.展开更多
Since the Practical Byzantine Fault Tolerance(PBFT)consensus mechanism can avoid the performance bottleneck of blockchain systems caused by Proof of Work(PoW),it has been widely used in many scenarios.However,in the b...Since the Practical Byzantine Fault Tolerance(PBFT)consensus mechanism can avoid the performance bottleneck of blockchain systems caused by Proof of Work(PoW),it has been widely used in many scenarios.However,in the blockchain system,each node is required to back up all transactions and block data of the system,which will waste a lot of storage resources.It is difficult to apply to scenarios with limited storage resources such as unmanned aerial vehicle networks and smart security protection;thus,it is often used in small-scale networks.In order to deploy PBFT-based blockchain systems in large-scale network scenarios,we propose an ultra-low storage overhead PBFT consensus(ULS-PBFT),which groups nodes hierarchically to limit the storage overhead within the group.In this paper,we first propose an optimal double-layer PBFT consensus from the perspective of minimizing the storage overhead,and prove that this consensus can significantly reduce the storage overhead.In addition,we also investigate the superiority of ULS-PBFT in terms of communication overhead while setting the security threshold in the presence of the possibility of Byzantine nodes.The simulation results demonstrate the advantages of ULS-PBFT.Then,we extend such grouping idea to the blockchain system with X-layer PBFT and analyze its storage and communication overhead.Finally,the node grouping strategy of double-layer PBFT is studied for four application scenarios when the performance of storage overhead,communication overhead,and security are considered comprehensively.展开更多
Biomarker detection is key to identifying health risks.However,designing sensitive and single-use biosensors for early diagnosis remains a major challenge.Here,we report submonolayer lasers on optical fibers as ultras...Biomarker detection is key to identifying health risks.However,designing sensitive and single-use biosensors for early diagnosis remains a major challenge.Here,we report submonolayer lasers on optical fibers as ultrasensitive and disposable biosensors.Telecom optical fibers serve as distributed optical microcavities with high Q-factor,great repeatability,and ultralow cost,which enables whispering-gallery laser emission to detect biomarkers.It is found that the sensing performance strongly depends on the number of gain molecules.The submonolayer lasers obtained a six-order-of-magnitude improvement in the lower limit of detection(LOD)when compared to saturated monolayer lasers.We further achieve an ultrasensitive immunoassay for a Parkinson's disease biomarker,alpha-synuclein(α-syn),with a lower LOD of 0.32 pM in serum,which is three orders of magnitude lower than theα-syn concentration in the serum of Parkinson's disease patients.Our demonstration of submonolayer biolaser offers great potentials in high-throughput clinical diagnosis with ultimate sensitivity.展开更多
Many breakthroughs in technologies are closely associated with the deep understanding and development of new material platforms.As the main material used in microelectronics,Si also plays a leading role in the develop...Many breakthroughs in technologies are closely associated with the deep understanding and development of new material platforms.As the main material used in microelectronics,Si also plays a leading role in the development of integrated photonics.The indirect bandgap,absence ofχ(2)nonlinearity and the parasitic nonlinear absorptions at the telecom band of Si imposed technological bottlenecks for further improving the performances and expanding the functionalities of Si microcavities in which the circulating light intensity is dramatically amplified.The past two decades have witnessed the burgeoning of the novel material platforms that are compatible with the complementary metal-oxide-semiconductor(COMS)process.In particular,the unprecedented optical properties of the emerging materials in the thin film form have resulted in revolutionary progress in microcavity photonics.In this review article,we summarize the recently developed material platforms for integrated photonics with the focus on chip-scale microcavity devices.The material characteristics,fabrication processes and device applications have been thoroughly discussed for the most widely used new material platforms.We also discuss open challenges and opportunities in microcavity photonics,such as heterogeneous integrated devices,and provide an outlook for the future development of integrated microcavities.展开更多
基金Supported by the National Key Research and Development Program of China(Grant Nos.2019YFA0705000 and 2017YFA0303700)the Key R&D Program of Guangdong Province(Grant No.2018B030329001)+1 种基金the Leading-Edge Technology Program of Jiangsu Natural Science Foundation(Grant No.BK20192001)the National Natural Science Foundation of China(Grant Nos.51890861,11690031,11621091,and 11674169)。
文摘We demonstrate a broadband optical parametric oscillation,using a sheet cavity,via cavity phase-matching.A21.2 THz broad comb-like spectrum is achieved,with a uniform line spacing of 133.0 GHz,despite a relatively large dispersion of 275.4 fs^(2)/mm around 1064 nm.With 22.6% high slope efficiency,and 14.9 kW peak power handling,this sheet optical parametric oscillator can be further developed for x^((2)) comb.
基金the financial support from the National Natural Science Foundation of China(Grant No.61875034)the 111 Project(Grant No.B14039)Seeding Project of Scientific and Technical Innovation of Sichuan Province(Grant No.2020107).
文摘Fiber optofluidic laser(FOFL)integrates optical fiber microcavity and microfluidic channel and provides many unique advantages for sensing applications.FOFLs not only inherit the advantages of lasers such as high sensitivity,high signal-to-noise ratio,and narrow linewidth,but also hold the unique features of optical fiber,including ease of integration,high repeatability,and low cost.With the development of new fiber structures and fabrication technologies,FOFLs become an important branch of optical fiber sensors,especially for application in biochemical detection.In this paper,the recent progress on FOFL is reviewed.We focuse mainly on the optical fiber resonators,gain medium,and the emerging sen sing applicatio ns.The prospects for FOFL are also discussed.We believe that the FOFL sensor provides a promising technology for biomedical analysis and environmental monitoring.
基金This work is supported by the National Natural Science Foundation of China （61107073, 61107072 and 61290312）, Fundamental Research Funds for the Central Universities （ZYGX2011J002）, Research Fund for the Doctoral Program of Higher Education of China （20110185120020）, Program for Changjiang Scholars and Innovative Research Team in University （PCSIRT, IRT1218）, and the 111 Project （B 14039）. Open Access This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author（s） and source are credited.
基金The authors greatly thank Dr. Zegao Wang and Prof. Yuanfu Chen of the State Key Lab of Electronic Thin Films and Integrated Devices, University of Electronic Science ＆ Technology of China, for their help on the preparation and test of the graphene used in the study and useful discussions. This work was supported by the National Natural Science Foundation of China under Grant 61290312, 61107072, and 61107073. It was also supported by Program for Changjiang Scholars and Innovative Research Team in Universities of China （PCSIRT） and the ＂111 Project＂ of China Education Ministry.
文摘The excitation of the surface field and evanescent enhancement in the graphene have shown sensitive to the refractive index of surrounding media and potential applications in high-sensitivity biochemical sensing. In this paper, we investigate the graphene-coated microfiber Bragg gratings （GMFBGs） with different diameters for ammonia gas sensing. The maximum sensitivity with 6pm/ppm was achieved experimentally when the microfiber＇s diameter was about 10 μm. Moreover, by adjusting the diameter of the GMFBG, the sensing performance of the GMFBGs could be optimized. Experimental results indicated that GMFBGs with the diameter of 8μm - 12μm would show the characteristics of the high sensitivity, relative low attenuation, and large dynamic range.
基金This work is supported by National Natural Science Foundation of China （61107073, 61107072 and 61290312）, Fundamental Research Funds for the Central Universities （ZYGX2011J002）, Research Fund for the Doctoral Program of Higher Education of China （20110185120020）, Program for Changjiang Scholars and Innovative Research Team in University （PCSIRT, IRT1218）, and the 111 Project （B 14039）.
基金National Key Research and Development Program of China(2021YFB2800602)National Natural Science Foundation of China(61975025,U2130106)State Key Laboratory Open Program(2022GZKF002)。
文摘Optical microcavities offer a promising platform for highly efficient light–matter interactions.Recently,the combination of microresonators and 2D materials in the nanoscale has further enriched the optoelectronics of microcavity geometries,spurring broad advances including lasers,nonlinear converters,modulators,and sensors.Here,we report the concept of compact dual-laser cogeneration in a graphene-microcavity fiber,which offers a way to cancel the optical common mode noises.Driven by a single 980 nm pump,orthogonally polarized laser lines are generated in a pair of degeneracy breaking modes.The two laser lines produce a heterodyne beat note at 118.96 MHz,with frequency noise down to 200 Hz~2∕Hz at 1 MHz offset,demonstrating a linewidth of 930 Hz in vacuum.This compact device enables on-line and label-free NH_(3) gas detection with high resolution,realizing a detection limit on a single pmol/L level,and a capability to quantitatively trace gas–graphene interactions.Such a combination of graphene optoelectronics and microcavity photonics demonstrates a novel physical paradigm for microlaser control and offers a new scheme for in situ chemical sensing.
基金This work is supported by the National Natural Science Foundation of China （61107073, 61107072, and 61290312）, Fundamental Research Funds for the Central Universities （ZYGX2011J002）, Research Fund for the Doctoral Program of Higher Education of China （20110185120020）, Program for Changjiang Scholars and Innovative Research Team in University （PCSIRT, IRT1218）, and the 111 Project （B 14039）.
基金the Natural Science Foundation of Sichuan Province under Grant 2022NSFSC0913and in part by the PCL Future Greater-Bay Area Network Facilities for Large-scale Experiments and Applications under Grant PCL2018KP001.
文摘Since the Practical Byzantine Fault Tolerance(PBFT)consensus mechanism can avoid the performance bottleneck of blockchain systems caused by Proof of Work(PoW),it has been widely used in many scenarios.However,in the blockchain system,each node is required to back up all transactions and block data of the system,which will waste a lot of storage resources.It is difficult to apply to scenarios with limited storage resources such as unmanned aerial vehicle networks and smart security protection;thus,it is often used in small-scale networks.In order to deploy PBFT-based blockchain systems in large-scale network scenarios,we propose an ultra-low storage overhead PBFT consensus(ULS-PBFT),which groups nodes hierarchically to limit the storage overhead within the group.In this paper,we first propose an optimal double-layer PBFT consensus from the perspective of minimizing the storage overhead,and prove that this consensus can significantly reduce the storage overhead.In addition,we also investigate the superiority of ULS-PBFT in terms of communication overhead while setting the security threshold in the presence of the possibility of Byzantine nodes.The simulation results demonstrate the advantages of ULS-PBFT.Then,we extend such grouping idea to the blockchain system with X-layer PBFT and analyze its storage and communication overhead.Finally,the node grouping strategy of double-layer PBFT is studied for four application scenarios when the performance of storage overhead,communication overhead,and security are considered comprehensively.
基金This work is supported by the National Natural Science Foundation of China(Grant Nos.62275043,61875034,62205007,11825402,and 62105006)the 111 Project(B14039)+4 种基金the Sichuan Science and Technology Program(2021YJ0101)the Fundamental Research Funds for the Central Universities(ZYGX2021YGCX007)the China Postdoctoral Science Foundation(Grant Nos.2021T1400232020M680187,and 2021M700208)the Young Elite Scientists Sponsorship Program by CAST(2022QNRC001)。
文摘Biomarker detection is key to identifying health risks.However,designing sensitive and single-use biosensors for early diagnosis remains a major challenge.Here,we report submonolayer lasers on optical fibers as ultrasensitive and disposable biosensors.Telecom optical fibers serve as distributed optical microcavities with high Q-factor,great repeatability,and ultralow cost,which enables whispering-gallery laser emission to detect biomarkers.It is found that the sensing performance strongly depends on the number of gain molecules.The submonolayer lasers obtained a six-order-of-magnitude improvement in the lower limit of detection(LOD)when compared to saturated monolayer lasers.We further achieve an ultrasensitive immunoassay for a Parkinson's disease biomarker,alpha-synuclein(α-syn),with a lower LOD of 0.32 pM in serum,which is three orders of magnitude lower than theα-syn concentration in the serum of Parkinson's disease patients.Our demonstration of submonolayer biolaser offers great potentials in high-throughput clinical diagnosis with ultimate sensitivity.
基金supported by the National Natural Science Foundation of China(Grant Nos.61234003,61434004,and 61504141)National Key Research and Development Program of ChinaCAS Interdisciplinary Project(Grant No.KJZD-EW-L11-04)。
文摘Many breakthroughs in technologies are closely associated with the deep understanding and development of new material platforms.As the main material used in microelectronics,Si also plays a leading role in the development of integrated photonics.The indirect bandgap,absence ofχ(2)nonlinearity and the parasitic nonlinear absorptions at the telecom band of Si imposed technological bottlenecks for further improving the performances and expanding the functionalities of Si microcavities in which the circulating light intensity is dramatically amplified.The past two decades have witnessed the burgeoning of the novel material platforms that are compatible with the complementary metal-oxide-semiconductor(COMS)process.In particular,the unprecedented optical properties of the emerging materials in the thin film form have resulted in revolutionary progress in microcavity photonics.In this review article,we summarize the recently developed material platforms for integrated photonics with the focus on chip-scale microcavity devices.The material characteristics,fabrication processes and device applications have been thoroughly discussed for the most widely used new material platforms.We also discuss open challenges and opportunities in microcavity photonics,such as heterogeneous integrated devices,and provide an outlook for the future development of integrated microcavities.
