Personalized health services are of paramount importance for the treatment and prevention of cardiorespiratory diseases,such as hypertension.The assessment of cardiorespiratory function and biometric identification(ID...Personalized health services are of paramount importance for the treatment and prevention of cardiorespiratory diseases,such as hypertension.The assessment of cardiorespiratory function and biometric identification(ID)is crucial for the effectiveness of such personalized health services.To effectively and accurately monitor pulse wave signals,thus achieving the assessment of cardiorespiratory function,a wearable photonic smart wristband based on an all-polymer sensing unit(All-PSU)is proposed.The smart wristband enables the assessment of cardiorespiratory function by continuously monitoring respiratory rate(RR),heart rate(HR),and blood pressure(BP).Furthermore,it can be utilized for biometric ID purposes.Through the analysis of pulse wave signals using power spectral density(PSD),accurate monitoring of RR and HR is achieved.Additionally,utilizing peak detection algorithms for feature extraction from pulse signals and subsequently employing a variety of machine learning methods,accurate BP monitoring and biometric ID have been realized.For biometric ID,the accuracy rate is 98.55%.Aiming to monitor RR,HR,BP,and ID,our solution demonstrates advantages in integration,functionality,and monitoring precision.These enhancements may contribute to the development of personalized health services aimed at the treatment and prevention of cardiorespiratory diseases.展开更多
Symmetry plays a crucial role in explorations of the laws of nature.Parity-time(PT)symmetry phenomena can lead to entirely real spectra in non-Hermitian systems,which attracts considerable attention in the fields of o...Symmetry plays a crucial role in explorations of the laws of nature.Parity-time(PT)symmetry phenomena can lead to entirely real spectra in non-Hermitian systems,which attracts considerable attention in the fields of optics and electronics because these phenomena provide a new tool for the manipulation of oscillation modes and nonreciprocal signal transmission.A potential new field of application is microwave photonics,an interdisciplinary field in which the interaction between microwaves and optical signals is exploited.In this article,we report the experimental use of PT symmetry in an optoelectronic oscillator(OEO),a key microwave photonics system that can generate singlefrequency sinusoidal signals with high spectral purity.PT symmetry is theoretically analyzed and experimentally observed in an OEO with two mutually coupled active oscillation cavities via a precise manipulation of the interplay between gain and loss in the two oscillation cavities.Stable single-frequency microwave oscillation is achieved without using any optical/electrical filters for oscillation mode selection,which is an indispensable requirement in traditional OEOs.This observation opens new avenues for signal generation and processing based on the PT symmetry principle in microwave photonics.展开更多
An optoelectronic oscillator(OEO)is a microwave photonic system that produces microwave signals with ultralow phase noise using a high-quality-factor optical energy storage element.This type of oscillator is desired i...An optoelectronic oscillator(OEO)is a microwave photonic system that produces microwave signals with ultralow phase noise using a high-quality-factor optical energy storage element.This type of oscillator is desired in various practical applications,such as communication links,signal processing,radar,metrology,radio astronomy,and reference clock distribution.Recently,new mode control and selection methods based on Fourier domain mode-locking and parity-time symmetry have been proposed and experimentally demonstrated in OEOs,which overcomes the long-existing mode building time and mode selection problems in a traditional OEO.Due to these mode control and selection methods,continuously chirped microwave waveforms can be generated directly from the OEO cavity and single-mode operation can be achieved without the need of ultranarrowband filters,which are not possible in a traditional OEO.Integrated OEOs with a compact size and low power consumption have also been demonstrated,which are key steps toward a new generation of compact and versatile OEOs for demanding applications.We review recent progress in the field of OEOs,with particular attention to new mode control and selection methods,as well as chip-scale integration of OEOs.展开更多
Flat electro-optical frequency combs play an important role in a wide range of applications,such as metrology,spectroscopy,or microwave photonics.As a key technology for the integration of optical circuits,silicon pho...Flat electro-optical frequency combs play an important role in a wide range of applications,such as metrology,spectroscopy,or microwave photonics.As a key technology for the integration of optical circuits,silicon photonics could benefit from on-chip,tunable,flat frequency comb generators.In this article,two different architectures based on silicon modulators are studied for this purpose.They rely on a time to frequency conversion principle to shape the comb envelope.Using a numerical model of the silicon traveling-wave phase modulators,their driving schemes are optimized before their performances are simulated and compared.A total of nine lines could be obtained within a 2 dB flatness,with a line-spacing ranging from 0.1 to 7 GHz.Since this tunability is a major asset of electro-optical frequency combs,the effect of segmenting the phase modulators is finally investigated,showing that the flat lines spacing could be extended up to 39 GHz by this method.展开更多
Incoherent optical processing of microwave signals,where low-coherence broadband light sources are employed instead of costly mode locked lasers,has attracted great interest thanks to its wide applications in microwav...Incoherent optical processing of microwave signals,where low-coherence broadband light sources are employed instead of costly mode locked lasers,has attracted great interest thanks to its wide applications in microwave photonics filtering[1–3],arbitrary generation[4–6]and analog to digital conversion[7]。展开更多
The optoelectronic oscillator(OEO)is a hybrid electrical/photonic device that leverages on the use of a high Q-factor energy storage element,such as a long and low loss fiber delay line to generate single frequency mi...The optoelectronic oscillator(OEO)is a hybrid electrical/photonic device that leverages on the use of a high Q-factor energy storage element,such as a long and low loss fiber delay line to generate single frequency microwave signals with ultra-low phase noise[1–8].However,a long fiber delay line results in a long mode building time associated with the cavity round trip,which makes impossible to generate a展开更多
Microwave photonics is a field that studies the interaction between microwave and optical waves for the generation,processing,control,and distribution of microwave signals by means of photonics.The key advantages of u...Microwave photonics is a field that studies the interaction between microwave and optical waves for the generation,processing,control,and distribution of microwave signals by means of photonics.The key advantages of using photonics for microwave applications include wide bandwidth,low loss,and large tunability.In addition,the distribution of microwave signals over optical fibers can avoid a serious problem,electromagnetic interferences,especially in an electromagnetic-complex environment.The intention of this feature issue is to provide participants in the 2013 Asia Communications and Photonics Conference(ACP2013)with an opportunity to publish an account of their microwave photonics research as a peer-reviewed archival paper.展开更多
基金funded by the National Key R&D Program of China(2022YFE0140400)the National Natural Science Foundation of China(62405027, 62111530238, 62003046)+3 种基金Supporting project of major scientific research projects of Beijing Normal University at Zhuhai (ZHPT2023007)supported by the Tang Scholar of Beijing Normal Universityco-funded by the financial support of the European Union under the REFRESH-Research Excellence For REgion Sustainability and High-tech Industries project number CZ.10.03.01/00/22003/0000048 via the Operational Programme Just Transitionthe scope of the projects CICECO-Aveiro Institute of Materials, UIDB/50011/2020 (DOI 10.54499/UIDB/50011/2020), UIDP/50011/2020 (DOI 10.54499/UIDP/50011/2020) & LA/P/0006/2020 (DOI 10.54499/LA/P/0006/2020) financed by national funds through the FCT/MCTES (PIDDAC)
文摘Personalized health services are of paramount importance for the treatment and prevention of cardiorespiratory diseases,such as hypertension.The assessment of cardiorespiratory function and biometric identification(ID)is crucial for the effectiveness of such personalized health services.To effectively and accurately monitor pulse wave signals,thus achieving the assessment of cardiorespiratory function,a wearable photonic smart wristband based on an all-polymer sensing unit(All-PSU)is proposed.The smart wristband enables the assessment of cardiorespiratory function by continuously monitoring respiratory rate(RR),heart rate(HR),and blood pressure(BP).Furthermore,it can be utilized for biometric ID purposes.Through the analysis of pulse wave signals using power spectral density(PSD),accurate monitoring of RR and HR is achieved.Additionally,utilizing peak detection algorithms for feature extraction from pulse signals and subsequently employing a variety of machine learning methods,accurate BP monitoring and biometric ID have been realized.For biometric ID,the accuracy rate is 98.55%.Aiming to monitor RR,HR,BP,and ID,our solution demonstrates advantages in integration,functionality,and monitoring precision.These enhancements may contribute to the development of personalized health services aimed at the treatment and prevention of cardiorespiratory diseases.
基金supported by the National Natural Science Foundation of China under 61535012 and 61522509supported by the National High-Tech Research and Development Program of China under 2015AA017102supported in part by the Thousand Young Talents Program.
文摘Symmetry plays a crucial role in explorations of the laws of nature.Parity-time(PT)symmetry phenomena can lead to entirely real spectra in non-Hermitian systems,which attracts considerable attention in the fields of optics and electronics because these phenomena provide a new tool for the manipulation of oscillation modes and nonreciprocal signal transmission.A potential new field of application is microwave photonics,an interdisciplinary field in which the interaction between microwaves and optical signals is exploited.In this article,we report the experimental use of PT symmetry in an optoelectronic oscillator(OEO),a key microwave photonics system that can generate singlefrequency sinusoidal signals with high spectral purity.PT symmetry is theoretically analyzed and experimentally observed in an OEO with two mutually coupled active oscillation cavities via a precise manipulation of the interplay between gain and loss in the two oscillation cavities.Stable single-frequency microwave oscillation is achieved without using any optical/electrical filters for oscillation mode selection,which is an indispensable requirement in traditional OEOs.This observation opens new avenues for signal generation and processing based on the PT symmetry principle in microwave photonics.
基金supported by the National Key Research and Development Program of China(2018YFB2201902,2018YFB2201901,2018YFB2201903)the National Natural Science Foundation of China(61925505,61535012,61705217)
文摘An optoelectronic oscillator(OEO)is a microwave photonic system that produces microwave signals with ultralow phase noise using a high-quality-factor optical energy storage element.This type of oscillator is desired in various practical applications,such as communication links,signal processing,radar,metrology,radio astronomy,and reference clock distribution.Recently,new mode control and selection methods based on Fourier domain mode-locking and parity-time symmetry have been proposed and experimentally demonstrated in OEOs,which overcomes the long-existing mode building time and mode selection problems in a traditional OEO.Due to these mode control and selection methods,continuously chirped microwave waveforms can be generated directly from the OEO cavity and single-mode operation can be achieved without the need of ultranarrowband filters,which are not possible in a traditional OEO.Integrated OEOs with a compact size and low power consumption have also been demonstrated,which are key steps toward a new generation of compact and versatile OEOs for demanding applications.We review recent progress in the field of OEOs,with particular attention to new mode control and selection methods,as well as chip-scale integration of OEOs.
基金Ministerio de Ciencia,Innovacion y UniversidadesMinistere de TEconomie,des Finances et de FlndustrieAgence Nationale de la Recherche(ANR-18-CE39-0009).
文摘Flat electro-optical frequency combs play an important role in a wide range of applications,such as metrology,spectroscopy,or microwave photonics.As a key technology for the integration of optical circuits,silicon photonics could benefit from on-chip,tunable,flat frequency comb generators.In this article,two different architectures based on silicon modulators are studied for this purpose.They rely on a time to frequency conversion principle to shape the comb envelope.Using a numerical model of the silicon traveling-wave phase modulators,their driving schemes are optimized before their performances are simulated and compared.A total of nine lines could be obtained within a 2 dB flatness,with a line-spacing ranging from 0.1 to 7 GHz.Since this tunability is a major asset of electro-optical frequency combs,the effect of segmenting the phase modulators is finally investigated,showing that the flat lines spacing could be extended up to 39 GHz by this method.
文摘Incoherent optical processing of microwave signals,where low-coherence broadband light sources are employed instead of costly mode locked lasers,has attracted great interest thanks to its wide applications in microwave photonics filtering[1–3],arbitrary generation[4–6]and analog to digital conversion[7]。
文摘The optoelectronic oscillator(OEO)is a hybrid electrical/photonic device that leverages on the use of a high Q-factor energy storage element,such as a long and low loss fiber delay line to generate single frequency microwave signals with ultra-low phase noise[1–8].However,a long fiber delay line results in a long mode building time associated with the cavity round trip,which makes impossible to generate a
文摘Microwave photonics is a field that studies the interaction between microwave and optical waves for the generation,processing,control,and distribution of microwave signals by means of photonics.The key advantages of using photonics for microwave applications include wide bandwidth,low loss,and large tunability.In addition,the distribution of microwave signals over optical fibers can avoid a serious problem,electromagnetic interferences,especially in an electromagnetic-complex environment.The intention of this feature issue is to provide participants in the 2013 Asia Communications and Photonics Conference(ACP2013)with an opportunity to publish an account of their microwave photonics research as a peer-reviewed archival paper.
