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
We investigate and experimentally demonstrate the gain improvement of single-pump fiber parametric amplifiers by using a suitable length of standard single-mode fiber(SSMF)inserted between two high-nonlinear fibers(HN...We investigate and experimentally demonstrate the gain improvement of single-pump fiber parametric amplifiers by using a suitable length of standard single-mode fiber(SSMF)inserted between two high-nonlinear fibers(HNLFs).The SSMF with different dispersion properties from the HNLF is employed for phase matching of the parametric processes,and the signal gain is improved as compared with the absence of the SSMF with experiment results.Furthermore,the effect of the input pump power and the fiber length of the SSMF on the output signal gain are discussed with experimental investigation.展开更多
Accurately forecasting the high-dimensional chaotic dynamics of semiconductor laser(SL)networks is essential in photonics research.In this study,we propose a spatiotemporal multiplexed photonic reservoir computing(STM...Accurately forecasting the high-dimensional chaotic dynamics of semiconductor laser(SL)networks is essential in photonics research.In this study,we propose a spatiotemporal multiplexed photonic reservoir computing(STM-PRC)architecture,specifically designed for parallel prediction of the high-dimensional chaotic dynamics in complex SL networks.This is accomplished by decomposing the prediction task into multiple simplified reservoirs,leveraging the intrinsic topological characteristics of the network.Additionally,we introduce a dimensionality reduction technique for high-dimensional chaotic datasets,which exploits the symmetrical properties of the network topology and cluster synchronization patterns derived from complex network theory.This approach further simplifies the prediction process and enhances the computational efficiency of the parallel STM-PRC system.The feasibility and effectiveness of the proposed framework are demonstrated through numerical simulations and corroborated by experimental validation.Our results expand the application potential of SL networks in all-optical communication systems and suggest new directions for optical information processing.展开更多
On-chip optical communications are growingly aiming at multimode operation together with mode-division multiplex-ing to further increase the transmission capacity.Optical switches,which are capable of optical signals ...On-chip optical communications are growingly aiming at multimode operation together with mode-division multiplex-ing to further increase the transmission capacity.Optical switches,which are capable of optical signals switching at the nodes,play a key role in optical networks.We demonstrate a 2×2 electro-optic Mach-Zehnder interferometer-based mode-and polar-ization-selective switch fabricated by standard complementary metal-oxide-semiconductor process.An electro optic tuner based on a PN-doped junction in one of the Mach-Zehnder interferometer arms enables dynamic switching in 11 ns.For all the channels,the overall insertion losses and inter-modal crosstalk values are below 9.03 and-15.86 dB at 1550 nm,respect-ively.展开更多
The performance of stimulated Brillouin scattering （SBS）-based slow light using a novel spectrally-sliced broadband incoherent pump source is numerically studied. The profile of the pump-power spectrum is determined...The performance of stimulated Brillouin scattering （SBS）-based slow light using a novel spectrally-sliced broadband incoherent pump source is numerically studied. The profile of the pump-power spectrum is determined by the transmission spectra of the optical filter followed by the polarized broadband incoherent pump source. We also investigate the performance of Gaussian-type and super-Gaussian-type filtering under different spectrally-slicedbandwidths and pump power levels for 2.5Gbit/s return-to-zero pulse （50% duty-cycle）. The pulse broadening is characterized by the full width of half maximum （FWHM） and the rms pulse width, respectively. However,the results obtained by the two kinds of measurement methods deviate from each other with increasing pump power. Compared with the regular Gaussian-type filtering, the pulse broadening can be significantly reduced using super-Gaussian-type filtering at the cost of a small reduction in delay time. Furthermore, the maximum improvement in pulse broadening of ＆#8710; BFWHM =28.4% and ＆#8710; B RMS =10.4% is achieved by using a five-order super-Gaussian-type filter and a pump power of 500mW.展开更多
Quantum randomness amplification protocols have increasingly attracted attention tbr their tantastic ability to ampllI~, weak randomness to almost ideal randomness by utilizing quantum systems. Recently, a realistic n...Quantum randomness amplification protocols have increasingly attracted attention tbr their tantastic ability to ampllI~, weak randomness to almost ideal randomness by utilizing quantum systems. Recently, a realistic noise-tolerant randomness amplification protocol using a finite number of untrusted devices was proposed. The protocol has the composable security against non-signalling eavesdroppers and could produce a single bit of randomness from weak randomness sources, which is certified by the violation of certain Bell inequalities. However, the protocol has a non-ignorable limitation on the min- entropy of independent sources. In this paper, we further develop the randomness amplification method and present a novel quantum randomness amplification protocol based on an explicit non-malleable two independent-source randomness extractor, which could remarkably reduce the above-mentioned specific limitation. Moreover, the composable security of our improved protocol is also proposed. Our results could significantly expand the application range for practical quantum randomness amplification, and provide a new insight on the practical design method for randomness extraction.展开更多
A scheme of polarization-mode-dispersion(PMD)mitigation in a polarization-division-multiplexing(PDM)system is proposed and demonstrated with 2×10 Gb/s return−to-zero on-off-keying(RZ-OOK)transmission.Simultaneous...A scheme of polarization-mode-dispersion(PMD)mitigation in a polarization-division-multiplexing(PDM)system is proposed and demonstrated with 2×10 Gb/s return−to-zero on-off-keying(RZ-OOK)transmission.Simultaneous mitigation for two polarization tributaries of the PDM signal is achieved based on the self-phase-modulation(SPM)effect and offset filtering in a polarization nonlinear loop configuration.The improvement of eye-diagram-based signal-to-noise ratio(SNR)is 3.5 dB in the presence of a 7.2-ps differential-group delay(DGD)when the pulsewidth of the PDM signal is∼16.6 ps.展开更多
A 32-channel wavelength division multiplexer with 100 GHz spacing is designed and fabricated by interleaving two silicon arrayed waveguide gratings(AWGs).It has a parallel structure consisting of two silicon 16-channe...A 32-channel wavelength division multiplexer with 100 GHz spacing is designed and fabricated by interleaving two silicon arrayed waveguide gratings(AWGs).It has a parallel structure consisting of two silicon 16-channel AWGs with200 GHz spacing and a Mach-Zehnder interferometer(MZI)with 200 GHz free spectral range.The 16 channels of one silicon AWG are interleaved with those of the other AWG in spectrum,but with an identical spacing of 200 GHz.For the composed wavelength division multiplexer,the experiment results reveal 32 wavelength channels in C-band,a wavelength spacing of 100 GHz,and a channel crosstalk lower than-15 dB.展开更多
High-performance ultra-compact polarization splitter-rotators(PSRs)are designed and experimentally demonstrated,using dual etching and a tapered asymmetrical directional coupler.First,two novel PSRs are designed with ...High-performance ultra-compact polarization splitter-rotators(PSRs)are designed and experimentally demonstrated,using dual etching and a tapered asymmetrical directional coupler.First,two novel PSRs are designed with nanowire and subwavelength grating cross-port waveguides and verified in simulations.Then,one of the two PSRs is fabricated.Experiment results reveal that the extinction ratio is higher than 28 dB or 32 dB at 1550 nm for the launched fundamental transverse magnetic or the transverse electric modes,while the corresponding insertion loss and polarization conversion loss are 0.33 dB and 0.18 dB,respectively.展开更多
Pump encoding is an effective approach to enhance the weak signal detection in distributed Brillouin fiber sensors.In this paper,a new encoding matrix that can improve the detection performance is proposed.Furthermore...Pump encoding is an effective approach to enhance the weak signal detection in distributed Brillouin fiber sensors.In this paper,a new encoding matrix that can improve the detection performance is proposed.Furthermore,a distributed fiber sensor for both single and encoding pump operations is numerically analyzed by using Brillouin-scattering coupled amplitudes equations.The results demonstrate that the matrix can reduce the transmission times for pumping light and simplify the coding process.The power of the scattering signal and the coding gain can be improved with the increasing code length.The detected scattering optical power is almost three orders of magnitude higher than that of the single pulse pump,as the coding length is 31,corresponding to 14.4 % improvement for the coding gain compared with the S matrix encoding method.At the same time,the temperature uncertainty can also be decreased.展开更多
We propose and experimentally demonstrate a photonic method for wideband multipath self-interference cancellation using a silicon photonic modulator chip.The chip generates phase-inverted reference signals by leveragi...We propose and experimentally demonstrate a photonic method for wideband multipath self-interference cancellation using a silicon photonic modulator chip.The chip generates phase-inverted reference signals by leveraging the opposite phase between optical sidebands.Effectively managing amplitude and phase imbalances between self-interference and reference signals,the approach rectifies discrepancies through consistent chip manufacturing and packaging processes.Employing photonic multi-dimensional multiplexing,including wavelength and polarization,enables the acquisition of multiple reference signals.Experimental results show multipath cancellation depths of 25.53 dB and 23.81 dB for bandwidths of 500 MHz and 1 GHz,achieved by superimposing 2-path reference signals.展开更多
To quantitatively evaluate the time-delay （TD） signatures of chaotic signals generated by vertical-cavity surface- emitting lasers （VCSELs） with polarization-rotated optical feedback （PROF）, we propose four case...To quantitatively evaluate the time-delay （TD） signatures of chaotic signals generated by vertical-cavity surface- emitting lasers （VCSELs） with polarization-rotated optical feedback （PROF）, we propose four cases of resolution coefficients R based on correlation functions. The resolution coefficient characteristics for the x-polarization （XP） mode, g-polarization （YP） mode and the total output are considered. The dependences of R on the feedback strength and feedback delay are discussed and compared carefully. The two-dimensional maps of R show that the TD signatures for the single polarization mode （i.e., XP or YP mode） are much more difficult to retrieve than those for the total output in the entire parameter space. Thus, by using single polarization mode as a chaotic carrier, the TD signatures are extremely difficult to be identified, which contributes a lot in the security-enhanced VCSELs-based chaotic optical communication systems.展开更多
Chaotic dynamics generated by vertical-cavity surface-emitting lasers(VCSELs)has stimulated a variety of applications in secure communication,random key distribution,and chaotic radar for its desirable characteristics...Chaotic dynamics generated by vertical-cavity surface-emitting lasers(VCSELs)has stimulated a variety of applications in secure communication,random key distribution,and chaotic radar for its desirable characteristics.The application of machine learning has made great progress in the prediction of chaotic dynamics.However,the performance is constrained by the training datasets,tedious hyper-parameter optimization,and processing speed.Herein,we propose a heterogeneous forecasting scheme for chaotic dynamics in VCSELs with knowledge-based photonic reservoir computing.An additional imperfect physical model of a VCSEL is introduced into photonic reservoir computing to mitigate the deficiency of the purely data-based approach,which yields improved processing speed,increased accuracy,simplified parameter optimization,and reduced training data size.It is demonstrated that the performance of our proposed scheme is robust to the deficiency of the physical model.Moreover,we elucidate that the performance of knowledge-based photonic reservoir computing will fluctuate with the complexity of chaotic dynamics.Finally,the generality of our results is validated experimentally in parameter spaces of feedback strength and injection strength of reservoir computing.The proposed approach suggests new insights into the prediction of chaotic dynamics of semiconductor lasers.展开更多
Covert wireless communications are unprecedentedly vital for security and privacy of individuals,government,and military bodies.Besides encryption,hiding signal transmission deeply under noise background highly prolif...Covert wireless communications are unprecedentedly vital for security and privacy of individuals,government,and military bodies.Besides encryption,hiding signal transmission deeply under noise background highly proliferates the covertness in the physical layer.A deep signal hiding leads to a low interception probability at the interceptor but a poor data recovery at the receiver.To ensure both high covertness and high-fidelity recovery,massive and dense optical comb channels are utilized for deep denoising through the analog spectrum convolution.Using an external modulation-based optical frequency comb(OFC)and a single detection branch,the available optical comb channels can sustainably scale up by breaking or greatly mitigating physical bottlenecks on immense hardware and spectrum requirements.Thus,a striking signal-to-noise ratio(SNR)rise can be achieved for deep denoising.Combination of 1024 comb channels(the first parallel comb channel number beyond 1000)and the analog spectrum convolution enable a record SNR enhancement of 29 dB for a microwave signal with a 10.24 GHz bandwidth and a 10 Mbit/s data rate,which is deeply hidden below the in-band noises by 18 dB or even 30 dB in both the frequency and time domains.This method opens a new avenue for covert communications.展开更多
Temperature sensing is essential for human health monitoring.High-sensitivity(>1 nm∕℃)fiber sensors always require long interference paths and temperature-sensitive materials,leading to a long sensor and thus slo...Temperature sensing is essential for human health monitoring.High-sensitivity(>1 nm∕℃)fiber sensors always require long interference paths and temperature-sensitive materials,leading to a long sensor and thus slow response(6–14 s).To date,it is still challenging for a fiber optic temperature sensor to have an ultrafast(~ms)response simultaneously with high sensitivity.Here,a side-polished single-mode/hollow/single-mode fiber(SPSHSF)structure is proposed to meet the challenge by using the length-independent sensitivity of an anti-resonant reflecting optical waveguide mechanism.With a polydimethylsiloxane filled sub-nanoliter volume cavity in the SP-SHSF,the SP-SHSF exhibits a high temperature sensitivity of 4.223 nm/℃ with a compact length of 1.6 mm,allowing an ultrafast response(16 ms)and fast recovery time(176 ms).The figure of merit(FOM),defined as the absolute ratio of sensitivity to response time,is proposed to assess the comprehensive performance of the sensor.The FOM of the proposed sensor reaches up to 263.94(nm/℃)∕s,which is more than two to three orders of magnitude higher than those of other temperature fiber optic sensors reported previously.Additionally,a threemonth cycle test shows that the sensor is highly robust,with excellent reversibility and accuracy,allowing it to be incorporated with a wearable face mask for detecting temperature changes during human breathing.The high FOM and high stability of the proposed sensing fiber structure provide an excellent opportunity to develop both ultrafast and highly sensitive fiber optic sensors for wearable respiratory monitoring and contactless in vitro detection.展开更多
Increasing the system capacity and spectral efficiency(SE)per unit bandwidth is one of the ultimate goals for data network designers,especially when using technologies compatible with current embedded fiber infrastruc...Increasing the system capacity and spectral efficiency(SE)per unit bandwidth is one of the ultimate goals for data network designers,especially when using technologies compatible with current embedded fiber infrastructures.Among these,the polarizationdivision-multiplexing(PDM)scheme,which supports two independent data channels on a single wavelength with orthogonal polarization states,has become a standard one in most state-of-art telecommunication systems.Currently,however,only two polarization states(that is,PDM)can be used,setting a barrier for further SE improvement.Assisted by coherent detection and digital signal processing,we propose and experimentally demonstrate a scheme for pseudo-PDM of four states(PPDM-4)by manipulation of four linearly polarized data channels with the same wavelength.Without any modification of the fiber link,we successfully transmit a 100-Gb s−1 PPDM-4 differential-phase-shift-keying signal over a 150-km single-mode fiber link.Such a method is expected to open new possibilities to fully explore the use of polarization freedom for capacity and SE improvement over existing fiber systems.展开更多
Heterogeneous Ⅲ-Ⅴ silicon(Si) photonic integration is considered one of the key methods for realizing power-and cost-effective optical interconnections, which are highly desired for future high-performance computers...Heterogeneous Ⅲ-Ⅴ silicon(Si) photonic integration is considered one of the key methods for realizing power-and cost-effective optical interconnections, which are highly desired for future high-performance computers and datacenters. We review the recent progress in heterogeneous Ⅲ-Ⅴ/Si photonic integration, including transceiving devices and components. We also describe the progress in the on-wafer characterization of photonic integration circuits, especially on the heterogeneous Ⅲ-Ⅴ/Si platform.展开更多
Signal processing is always the heart of the overall information technology and industry,providing enabling solutions for the processing,understanding,learning,retrieval,mining,and extraction of information from diffe...Signal processing is always the heart of the overall information technology and industry,providing enabling solutions for the processing,understanding,learning,retrieval,mining,and extraction of information from different signals.Regarding the all-optical signal processing,it dates back to the 1980s when the electronic bottleneck展开更多
An approach to generate a flat optical comb with tunable comb spacing and adjustable comb number is proposed.In the proposed approach,a Mach-Zehnder modulator（MZM）,being biased to generate two carrier-suppressed fir...An approach to generate a flat optical comb with tunable comb spacing and adjustable comb number is proposed.In the proposed approach,a Mach-Zehnder modulator（MZM）,being biased to generate two carrier-suppressed first-order sidebands,is cascaded with a phase modulator.The two optical sidebands are then sent to the phase modulator to generate two identical,but frequency-shifted phase-modulated spectra.Thanks to the complementary nature of the two adjacent comb lines in the phase-modulated spectra,the overlapping of the two spectra would lead to the generation of a flat optical comb.Since only the phase modulation index or the microwave power is needed to be adjusted,the system is easy to be implemented with tunable comb spacing and adjustable comb number.Numerical simulations are performed,and the approach is verified by an experiment.展开更多
A novel polarization monitoring scheme for polarization division multiplexed （PDM） systems is proposed. By using a tag light transmitted in different but close wavelength to the data signal as the feedback control, ...A novel polarization monitoring scheme for polarization division multiplexed （PDM） systems is proposed. By using a tag light transmitted in different but close wavelength to the data signal as the feedback control, the scheme can demultiplex automatically two orthogonal polarizations in PDM systems. The effectiveness of the scheme is demonstrated experimentally in a 2×10-Gb/s on-off-keying （OOK） PDM transmission system.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 Grant Nos 60972003 and 61111140390the National Basic Research Program of China under Grant No 2012CB315704.
文摘We investigate and experimentally demonstrate the gain improvement of single-pump fiber parametric amplifiers by using a suitable length of standard single-mode fiber(SSMF)inserted between two high-nonlinear fibers(HNLFs).The SSMF with different dispersion properties from the HNLF is employed for phase matching of the parametric processes,and the signal gain is improved as compared with the absence of the SSMF with experiment results.Furthermore,the effect of the input pump power and the fiber length of the SSMF on the output signal gain are discussed with experimental investigation.
基金supported in part by National Natural Science Foundation of China under Grant(Nos.62431024,U22A2089,62375228)Sichuan Science Fund for Distinguished Young Scholars(2023NSFSC1969)Fundamental Research Funds for the Central Universities(2682025ZTPY058)。
文摘Accurately forecasting the high-dimensional chaotic dynamics of semiconductor laser(SL)networks is essential in photonics research.In this study,we propose a spatiotemporal multiplexed photonic reservoir computing(STM-PRC)architecture,specifically designed for parallel prediction of the high-dimensional chaotic dynamics in complex SL networks.This is accomplished by decomposing the prediction task into multiple simplified reservoirs,leveraging the intrinsic topological characteristics of the network.Additionally,we introduce a dimensionality reduction technique for high-dimensional chaotic datasets,which exploits the symmetrical properties of the network topology and cluster synchronization patterns derived from complex network theory.This approach further simplifies the prediction process and enhances the computational efficiency of the parallel STM-PRC system.The feasibility and effectiveness of the proposed framework are demonstrated through numerical simulations and corroborated by experimental validation.Our results expand the application potential of SL networks in all-optical communication systems and suggest new directions for optical information processing.
基金supported in part by the National Key Research and Development Program of China under Grant 2019YFB2203600the National Natural Science Foundation of China(NSFC)under Grant 61975115/61835008/62035016the Science and Technology Commission of Shanghai Municipality under Grant 2017SHZDZX03。
文摘On-chip optical communications are growingly aiming at multimode operation together with mode-division multiplex-ing to further increase the transmission capacity.Optical switches,which are capable of optical signals switching at the nodes,play a key role in optical networks.We demonstrate a 2×2 electro-optic Mach-Zehnder interferometer-based mode-and polar-ization-selective switch fabricated by standard complementary metal-oxide-semiconductor process.An electro optic tuner based on a PN-doped junction in one of the Mach-Zehnder interferometer arms enables dynamic switching in 11 ns.For all the channels,the overall insertion losses and inter-modal crosstalk values are below 9.03 and-15.86 dB at 1550 nm,respect-ively.
文摘The performance of stimulated Brillouin scattering （SBS）-based slow light using a novel spectrally-sliced broadband incoherent pump source is numerically studied. The profile of the pump-power spectrum is determined by the transmission spectra of the optical filter followed by the polarized broadband incoherent pump source. We also investigate the performance of Gaussian-type and super-Gaussian-type filtering under different spectrally-slicedbandwidths and pump power levels for 2.5Gbit/s return-to-zero pulse （50% duty-cycle）. The pulse broadening is characterized by the full width of half maximum （FWHM） and the rms pulse width, respectively. However,the results obtained by the two kinds of measurement methods deviate from each other with increasing pump power. Compared with the regular Gaussian-type filtering, the pulse broadening can be significantly reduced using super-Gaussian-type filtering at the cost of a small reduction in delay time. Furthermore, the maximum improvement in pulse broadening of ＆#8710; BFWHM =28.4% and ＆#8710; B RMS =10.4% is achieved by using a five-order super-Gaussian-type filter and a pump power of 500mW.
基金Project supported by the National Natural Science Foundation of China(Grant No.61775185)
文摘Quantum randomness amplification protocols have increasingly attracted attention tbr their tantastic ability to ampllI~, weak randomness to almost ideal randomness by utilizing quantum systems. Recently, a realistic noise-tolerant randomness amplification protocol using a finite number of untrusted devices was proposed. The protocol has the composable security against non-signalling eavesdroppers and could produce a single bit of randomness from weak randomness sources, which is certified by the violation of certain Bell inequalities. However, the protocol has a non-ignorable limitation on the min- entropy of independent sources. In this paper, we further develop the randomness amplification method and present a novel quantum randomness amplification protocol based on an explicit non-malleable two independent-source randomness extractor, which could remarkably reduce the above-mentioned specific limitation. Moreover, the composable security of our improved protocol is also proposed. Our results could significantly expand the application range for practical quantum randomness amplification, and provide a new insight on the practical design method for randomness extraction.
基金by the National Basic Research Program of China under Grant No 2012CB315704the Program for New Century Excellent Talents in Universities of the Ministry of Education of China(NCET-08-0821)+1 种基金the Research Project in Sichuan Province(2010HH0009)the State Key Laboratory of Advanced Optical Communication Systems and Networks,China.
文摘A scheme of polarization-mode-dispersion(PMD)mitigation in a polarization-division-multiplexing(PDM)system is proposed and demonstrated with 2×10 Gb/s return−to-zero on-off-keying(RZ-OOK)transmission.Simultaneous mitigation for two polarization tributaries of the PDM signal is achieved based on the self-phase-modulation(SPM)effect and offset filtering in a polarization nonlinear loop configuration.The improvement of eye-diagram-based signal-to-noise ratio(SNR)is 3.5 dB in the presence of a 7.2-ps differential-group delay(DGD)when the pulsewidth of the PDM signal is∼16.6 ps.
基金Project supported by the National Key Research and Development Program of China(Grant No.2019YFB2203600)。
文摘A 32-channel wavelength division multiplexer with 100 GHz spacing is designed and fabricated by interleaving two silicon arrayed waveguide gratings(AWGs).It has a parallel structure consisting of two silicon 16-channel AWGs with200 GHz spacing and a Mach-Zehnder interferometer(MZI)with 200 GHz free spectral range.The 16 channels of one silicon AWG are interleaved with those of the other AWG in spectrum,but with an identical spacing of 200 GHz.For the composed wavelength division multiplexer,the experiment results reveal 32 wavelength channels in C-band,a wavelength spacing of 100 GHz,and a channel crosstalk lower than-15 dB.
基金supported by the National Key Research and Development Program of China(No.2019YFB2203600)。
文摘High-performance ultra-compact polarization splitter-rotators(PSRs)are designed and experimentally demonstrated,using dual etching and a tapered asymmetrical directional coupler.First,two novel PSRs are designed with nanowire and subwavelength grating cross-port waveguides and verified in simulations.Then,one of the two PSRs is fabricated.Experiment results reveal that the extinction ratio is higher than 28 dB or 32 dB at 1550 nm for the launched fundamental transverse magnetic or the transverse electric modes,while the corresponding insertion loss and polarization conversion loss are 0.33 dB and 0.18 dB,respectively.
基金supported by the Program for New Century Excellent Talents in University of China (No. 08-0821)and the Fund of State Key Laboratory of Advanced Optical Communication Systems and Networks,China
文摘Pump encoding is an effective approach to enhance the weak signal detection in distributed Brillouin fiber sensors.In this paper,a new encoding matrix that can improve the detection performance is proposed.Furthermore,a distributed fiber sensor for both single and encoding pump operations is numerically analyzed by using Brillouin-scattering coupled amplitudes equations.The results demonstrate that the matrix can reduce the transmission times for pumping light and simplify the coding process.The power of the scattering signal and the coding gain can be improved with the increasing code length.The detected scattering optical power is almost three orders of magnitude higher than that of the single pulse pump,as the coding length is 31,corresponding to 14.4 % improvement for the coding gain compared with the S matrix encoding method.At the same time,the temperature uncertainty can also be decreased.
基金supported by the National Key Research and Development Program of China(No.2022YFB2802701)the National Natural Science Foundation of China(Nos.U23A20376,62075185,and 62271422)the Sichuan Science Fund for Distinguished Young Scholars(No.24NSFJQ0195).
文摘We propose and experimentally demonstrate a photonic method for wideband multipath self-interference cancellation using a silicon photonic modulator chip.The chip generates phase-inverted reference signals by leveraging the opposite phase between optical sidebands.Effectively managing amplitude and phase imbalances between self-interference and reference signals,the approach rectifies discrepancies through consistent chip manufacturing and packaging processes.Employing photonic multi-dimensional multiplexing,including wavelength and polarization,enables the acquisition of multiple reference signals.Experimental results show multipath cancellation depths of 25.53 dB and 23.81 dB for bandwidths of 500 MHz and 1 GHz,achieved by superimposing 2-path reference signals.
基金Supported by the National Natural Science Foundation of China under Grant No 60976039, the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No 20070613058, the Fundamental Research Funds for the Central Universities （No 2010XS18）, and the Funds for the Excellent PhD Dissertation of Southwest Jiaotong University （2010）.
文摘To quantitatively evaluate the time-delay （TD） signatures of chaotic signals generated by vertical-cavity surface- emitting lasers （VCSELs） with polarization-rotated optical feedback （PROF）, we propose four cases of resolution coefficients R based on correlation functions. The resolution coefficient characteristics for the x-polarization （XP） mode, g-polarization （YP） mode and the total output are considered. The dependences of R on the feedback strength and feedback delay are discussed and compared carefully. The two-dimensional maps of R show that the TD signatures for the single polarization mode （i.e., XP or YP mode） are much more difficult to retrieve than those for the total output in the entire parameter space. Thus, by using single polarization mode as a chaotic carrier, the TD signatures are extremely difficult to be identified, which contributes a lot in the security-enhanced VCSELs-based chaotic optical communication systems.
基金National Key Research and Development Program of China(2021YFB2801900)National Natural Science Foundation of China(U22A2089,62104203,62375228,62431024)+1 种基金Sichuan Science Fund for Distinguished Young Scholars(2023NSFSC1969)Fundamental Research Funds for the Central Universities(2682022CX024,2682023CG003)。
文摘Chaotic dynamics generated by vertical-cavity surface-emitting lasers(VCSELs)has stimulated a variety of applications in secure communication,random key distribution,and chaotic radar for its desirable characteristics.The application of machine learning has made great progress in the prediction of chaotic dynamics.However,the performance is constrained by the training datasets,tedious hyper-parameter optimization,and processing speed.Herein,we propose a heterogeneous forecasting scheme for chaotic dynamics in VCSELs with knowledge-based photonic reservoir computing.An additional imperfect physical model of a VCSEL is introduced into photonic reservoir computing to mitigate the deficiency of the purely data-based approach,which yields improved processing speed,increased accuracy,simplified parameter optimization,and reduced training data size.It is demonstrated that the performance of our proposed scheme is robust to the deficiency of the physical model.Moreover,we elucidate that the performance of knowledge-based photonic reservoir computing will fluctuate with the complexity of chaotic dynamics.Finally,the generality of our results is validated experimentally in parameter spaces of feedback strength and injection strength of reservoir computing.The proposed approach suggests new insights into the prediction of chaotic dynamics of semiconductor lasers.
基金National Key Research and Development Program of China(2019YFB2203200)National Natural Science Foundation of China(61922069,61775185).
文摘Covert wireless communications are unprecedentedly vital for security and privacy of individuals,government,and military bodies.Besides encryption,hiding signal transmission deeply under noise background highly proliferates the covertness in the physical layer.A deep signal hiding leads to a low interception probability at the interceptor but a poor data recovery at the receiver.To ensure both high covertness and high-fidelity recovery,massive and dense optical comb channels are utilized for deep denoising through the analog spectrum convolution.Using an external modulation-based optical frequency comb(OFC)and a single detection branch,the available optical comb channels can sustainably scale up by breaking or greatly mitigating physical bottlenecks on immense hardware and spectrum requirements.Thus,a striking signal-to-noise ratio(SNR)rise can be achieved for deep denoising.Combination of 1024 comb channels(the first parallel comb channel number beyond 1000)and the analog spectrum convolution enable a record SNR enhancement of 29 dB for a microwave signal with a 10.24 GHz bandwidth and a 10 Mbit/s data rate,which is deeply hidden below the in-band noises by 18 dB or even 30 dB in both the frequency and time domains.This method opens a new avenue for covert communications.
基金National Key Research and Development Program of China(2021YFB2800801)National Natural Science Foundation of China(12174155,12174156,61675092,62105125)+4 种基金Natural Science Foundation of Guangdong Province for Distinguished Young Scholars(2020B1515020024)Key-Area Research and Development Program of Guangdong Province(2019B010138004)Aeronautical Science Foundation of China(201708W4001,201808W4001)Special Project in Key Fields of the Higher Education Institutions of Guangdong Province(2020ZDZX3022)Project of STRPAT of EC Laboratory(ZHD201902)。
文摘Temperature sensing is essential for human health monitoring.High-sensitivity(>1 nm∕℃)fiber sensors always require long interference paths and temperature-sensitive materials,leading to a long sensor and thus slow response(6–14 s).To date,it is still challenging for a fiber optic temperature sensor to have an ultrafast(~ms)response simultaneously with high sensitivity.Here,a side-polished single-mode/hollow/single-mode fiber(SPSHSF)structure is proposed to meet the challenge by using the length-independent sensitivity of an anti-resonant reflecting optical waveguide mechanism.With a polydimethylsiloxane filled sub-nanoliter volume cavity in the SP-SHSF,the SP-SHSF exhibits a high temperature sensitivity of 4.223 nm/℃ with a compact length of 1.6 mm,allowing an ultrafast response(16 ms)and fast recovery time(176 ms).The figure of merit(FOM),defined as the absolute ratio of sensitivity to response time,is proposed to assess the comprehensive performance of the sensor.The FOM of the proposed sensor reaches up to 263.94(nm/℃)∕s,which is more than two to three orders of magnitude higher than those of other temperature fiber optic sensors reported previously.Additionally,a threemonth cycle test shows that the sensor is highly robust,with excellent reversibility and accuracy,allowing it to be incorporated with a wearable face mask for detecting temperature changes during human breathing.The high FOM and high stability of the proposed sensing fiber structure provide an excellent opportunity to develop both ultrafast and highly sensitive fiber optic sensors for wearable respiratory monitoring and contactless in vitro detection.
基金supported by the Natural Science Foundation of China(Nos.61335005,61325023,61275068 and 61401378)the National Basic Research Program of China(2012CB315704)。
文摘Increasing the system capacity and spectral efficiency(SE)per unit bandwidth is one of the ultimate goals for data network designers,especially when using technologies compatible with current embedded fiber infrastructures.Among these,the polarizationdivision-multiplexing(PDM)scheme,which supports two independent data channels on a single wavelength with orthogonal polarization states,has become a standard one in most state-of-art telecommunication systems.Currently,however,only two polarization states(that is,PDM)can be used,setting a barrier for further SE improvement.Assisted by coherent detection and digital signal processing,we propose and experimentally demonstrate a scheme for pseudo-PDM of four states(PPDM-4)by manipulation of four linearly polarized data channels with the same wavelength.Without any modification of the fiber link,we successfully transmit a 100-Gb s−1 PPDM-4 differential-phase-shift-keying signal over a 150-km single-mode fiber link.Such a method is expected to open new possibilities to fully explore the use of polarization freedom for capacity and SE improvement over existing fiber systems.
基金Project supported by the National Natural Science Foundation of China(Nos.61875240,61421002,and 61435010)the Science Foundation for Youths of Sichuan Province,China(No.2016JQ0014)
文摘Heterogeneous Ⅲ-Ⅴ silicon(Si) photonic integration is considered one of the key methods for realizing power-and cost-effective optical interconnections, which are highly desired for future high-performance computers and datacenters. We review the recent progress in heterogeneous Ⅲ-Ⅴ/Si photonic integration, including transceiving devices and components. We also describe the progress in the on-wafer characterization of photonic integration circuits, especially on the heterogeneous Ⅲ-Ⅴ/Si platform.
文摘Signal processing is always the heart of the overall information technology and industry,providing enabling solutions for the processing,understanding,learning,retrieval,mining,and extraction of information from different signals.Regarding the all-optical signal processing,it dates back to the 1980s when the electronic bottleneck
基金supported by the Natural Sciences and Engineering Research Council of Canada(NSERC)X. Zou was supported by the China Scholarship Councilthe National Natural Science Foundation of China(No. 60976039).
文摘An approach to generate a flat optical comb with tunable comb spacing and adjustable comb number is proposed.In the proposed approach,a Mach-Zehnder modulator（MZM）,being biased to generate two carrier-suppressed first-order sidebands,is cascaded with a phase modulator.The two optical sidebands are then sent to the phase modulator to generate two identical,but frequency-shifted phase-modulated spectra.Thanks to the complementary nature of the two adjacent comb lines in the phase-modulated spectra,the overlapping of the two spectra would lead to the generation of a flat optical comb.Since only the phase modulation index or the microwave power is needed to be adjusted,the system is easy to be implemented with tunable comb spacing and adjustable comb number.Numerical simulations are performed,and the approach is verified by an experiment.
基金supported by the Program for New Century Excellent Talents in the University (NCET-08-0821)Ministry of Education, China, the Research Project in Sichuan Province of China (No. 2010HH0009)the Scientific Research Foundation for the Returned Overseas Chinese Scholars, Ministry of Education of China, and the State Key Laboratory of Advanced Op-tical Communication Systems and Networks of China.
文摘A novel polarization monitoring scheme for polarization division multiplexed （PDM） systems is proposed. By using a tag light transmitted in different but close wavelength to the data signal as the feedback control, the scheme can demultiplex automatically two orthogonal polarizations in PDM systems. The effectiveness of the scheme is demonstrated experimentally in a 2×10-Gb/s on-off-keying （OOK） PDM transmission system.
