We propose a side-core holey fiber （SCHF）-based surface plasmon resonance （SPR） sensor to achieve high refractive index （RI） sensitivity. The SCHF structure can facilitate analyte filling and enhance the overlap...We propose a side-core holey fiber （SCHF）-based surface plasmon resonance （SPR） sensor to achieve high refractive index （RI） sensitivity. The SCHF structure can facilitate analyte filling and enhance the overlapping area of the core mode and surface plasmon polariton （SPP） mode. The coupling properties of the sensor are analyzed by numerical simulation. The maximum sensitivity of 5000 nm/RIU in an RI range of 1.33-1.44, and the average sensitivity of 9295 nm/RIU in an RI range from 1.44 to 1.54 can be obtained.展开更多
The detection of the state of polarization(SOP)of light is essential for many optical applications.However,cost-effective SOP measurement is a challenge due to the complexity of conventional methods and the poor trans...The detection of the state of polarization(SOP)of light is essential for many optical applications.However,cost-effective SOP measurement is a challenge due to the complexity of conventional methods and the poor transferability of new methods.We propose a straightforward,low-cost,and portable SOP measurement system based on the multimode fiber speckle.A convolutional neural network is utilized to establish the mapping relationship between speckle and Stokes parameters.The lowest root-mean-square error of the estimated SOP on the Poincarésphere can be 0.0042.This method is distinguished by its low cost,clear structure,and applicability to different wavelengths with high precision.The proposed method is of great value in polarization-related applications.展开更多
We propose and validate a novel optical semantic transmission scheme using multimode fiber(MMF).By leveraging the frequency sensitivity of intermodal dispersion in MMFs,we achieve high-dimensional semantic encoding an...We propose and validate a novel optical semantic transmission scheme using multimode fiber(MMF).By leveraging the frequency sensitivity of intermodal dispersion in MMFs,we achieve high-dimensional semantic encoding and decoding in the frequency domain.Our system maps symbols to 128 distinct frequencies spaced at 600 kHz intervals,demonstrating a seven-fold increase in capacity compared to conventional communication encoding.We further enhance spectral efficiency by implementing 4-level pulse amplitude modulation(PAM-4),achieving 9.12 bits/s/Hz without decoding errors.Additionally,we explore the application of this system for sentiment analysis using the IMDb movie review dataset.By encoding semantically similar symbols to adjacent frequencies,the system's noise tolerance is effectively improved,facilitating accurate sentiment analysis.This work highlights the potential of MMF-based semantic communication to enhance both capacity and robustness in optical communication systems,offering promising applications in bandwidth-constrained and noisy environments.展开更多
We propose a novel waveguide design of polarization-maintaining few mode fiber(PM-FMF) supporting ≥10non-degenerate modes, utilizing a central circular air hole and a circumjacent elliptical-ring core. The structure ...We propose a novel waveguide design of polarization-maintaining few mode fiber(PM-FMF) supporting ≥10non-degenerate modes, utilizing a central circular air hole and a circumjacent elliptical-ring core. The structure endows a new degree of freedom to adjust the birefringence of all the guided modes, including the fundamental polarization mode. Numerical simulations demonstrate that, by optimizing the air hole and elliptical-ring core,a PM-FMF supporting 10 distinctive polarization modes has been achieved, and the effective index difference Δn_(eff) between the adjacent guided modes could be kept larger than 1.32 × 10^(-4) over the whole C +L band. The proposed fiber structure can flexibly tailored to support an even larger number of modes in PM-FMF(14-mode PM-FMF has been demonstrated as an example), which can be readily applicable to a scalable mode division multiplexing system.展开更多
Speckle patterns generated by the intermodal interference of multimode fibers enable accurate broadband wavelength measurements.However,the measurement speed is limited by the frame rate of the camera that captures th...Speckle patterns generated by the intermodal interference of multimode fibers enable accurate broadband wavelength measurements.However,the measurement speed is limited by the frame rate of the camera that captures the patterns.We propose a compact and cost-effective ultrafast wavemeter based on multimode and multicore fibers,which employs spectral-spatial-temporal mapping.The speckle patterns generated by multimode fibers enable spectral-to-spatial mapping,which is then sampled by a multicore fiber into a pulse sequence to implement spatial-to-temporal mapping.A high-speed single-pixel photodetector is employed to capture the pulse sequence,which is analysed using a multilayer perceptron to estimate the wavelength.The feasibility of the proposed wavelength estimation method is experimentally verified,achieving a measurement rate of 100 MHz with a resolution of 2.7 pm in a 1 nm operation bandwidth.展开更多
With the benefits of low latency,wide transmission bandwidth,and large mode field area,hollow-core antiresonant fiber(HC-ARF)has been a research hotspot in the past decade.In this paper,a hollow core step-index antire...With the benefits of low latency,wide transmission bandwidth,and large mode field area,hollow-core antiresonant fiber(HC-ARF)has been a research hotspot in the past decade.In this paper,a hollow core step-index antiresonant fiber(HC-SARF),with stepped refractive indices cladding,is proposed and numerically demonstrated with the benefits of loss reduction and bending improvement.Glass-based capil-laries with both high(n=1.45)and low(as low as n=1.36)refractive indices layers are introduced and formatted in the cladding air holes.Using the finite element method to perform numerical analysis of the designed fiber,results show that at the laser wavelengths of 980 and 1064 nm,the confinement loss is favorably reduced by about 6 dB/km compared with the conventional uniform cladding HC-ARF.The bending loss,around 15 cm bending radius of this fiber,is also reduced by 2 dB/km.The cladding air hole radius in this fiber is further investigated to optimize the confinement loss and the mode field diameter with single-mode transmission behavior.This proposed HC-SARF has great potential in optical fiber transmission and high energy delivery.展开更多
The time delay （TD） signature is a critical parameter in optical chaos-based applications. The feasi- bility of extracting the TD has been a crucial issue that significantly influences the performance of these appli...The time delay （TD） signature is a critical parameter in optical chaos-based applications. The feasi- bility of extracting the TD has been a crucial issue that significantly influences the performance of these applica- tions. In this paper, statistical analyses have been conducted to extract the TD signatures from different types of coupled optical chaos systems. More specifically, a mutually coupled semiconductor laser chaotic system, an intensity-coupled electro-optic chaotic system, and a phase-coupled electro-optic chaotic system are studied in detail. These systems are proposed to resist the attack strategies against the TD signature. They are proved to be effective under statistical analyzes, such as the self- correlation fimction （SF） and mutual information （MI）. However, only a single output has been considered for the attack process in the existing research. We demonstrated that the TD signature can still be extracted by analyzing the mutual statistical relationship between the different output signals which are generated simultaneously by the coupled system. Furthermore, we find that the extraction strategy is effective for a wide parameter range in these schemes.展开更多
基金Project supported by the Major Projects of the National Natural Science Foundation of China(Grant No.61290315)the National Natural Science Foundation of China(Grant No.61340057)the Special Program of the National Modern Service Industrial Development Foundation of China(Grant No.[2012]14)
文摘We propose a side-core holey fiber （SCHF）-based surface plasmon resonance （SPR） sensor to achieve high refractive index （RI） sensitivity. The SCHF structure can facilitate analyte filling and enhance the overlapping area of the core mode and surface plasmon polariton （SPP） mode. The coupling properties of the sensor are analyzed by numerical simulation. The maximum sensitivity of 5000 nm/RIU in an RI range of 1.33-1.44, and the average sensitivity of 9295 nm/RIU in an RI range from 1.44 to 1.54 can be obtained.
基金supported by the National Key Research and Development Program of China(Grant No.2021YFB2800902)the National Natural Science Foundation of China(Grant No.62225110)+1 种基金the Key Research and Development Program of Hubei Province(No.2022BAA001)the Innovation Fund of WNLO.
文摘The detection of the state of polarization(SOP)of light is essential for many optical applications.However,cost-effective SOP measurement is a challenge due to the complexity of conventional methods and the poor transferability of new methods.We propose a straightforward,low-cost,and portable SOP measurement system based on the multimode fiber speckle.A convolutional neural network is utilized to establish the mapping relationship between speckle and Stokes parameters.The lowest root-mean-square error of the estimated SOP on the Poincarésphere can be 0.0042.This method is distinguished by its low cost,clear structure,and applicability to different wavelengths with high precision.The proposed method is of great value in polarization-related applications.
基金supported by the National Key Research and Development Program of China(2023YFB2906300)National Natural Science Foundation of China(61931010,62225110)JD project of Hubei province(2023BAA013).
文摘We propose and validate a novel optical semantic transmission scheme using multimode fiber(MMF).By leveraging the frequency sensitivity of intermodal dispersion in MMFs,we achieve high-dimensional semantic encoding and decoding in the frequency domain.Our system maps symbols to 128 distinct frequencies spaced at 600 kHz intervals,demonstrating a seven-fold increase in capacity compared to conventional communication encoding.We further enhance spectral efficiency by implementing 4-level pulse amplitude modulation(PAM-4),achieving 9.12 bits/s/Hz without decoding errors.Additionally,we explore the application of this system for sentiment analysis using the IMDb movie review dataset.By encoding semantically similar symbols to adjacent frequencies,the system's noise tolerance is effectively improved,facilitating accurate sentiment analysis.This work highlights the potential of MMF-based semantic communication to enhance both capacity and robustness in optical communication systems,offering promising applications in bandwidth-constrained and noisy environments.
基金National Natural Science Foundation of China(NSFC)(61331010,61205063)863 High Technology plan(2015AA016904)Program for New Century Excellent Talents in University(NCET)(NCET-13-0235)
文摘We propose a novel waveguide design of polarization-maintaining few mode fiber(PM-FMF) supporting ≥10non-degenerate modes, utilizing a central circular air hole and a circumjacent elliptical-ring core. The structure endows a new degree of freedom to adjust the birefringence of all the guided modes, including the fundamental polarization mode. Numerical simulations demonstrate that, by optimizing the air hole and elliptical-ring core,a PM-FMF supporting 10 distinctive polarization modes has been achieved, and the effective index difference Δn_(eff) between the adjacent guided modes could be kept larger than 1.32 × 10^(-4) over the whole C +L band. The proposed fiber structure can flexibly tailored to support an even larger number of modes in PM-FMF(14-mode PM-FMF has been demonstrated as an example), which can be readily applicable to a scalable mode division multiplexing system.
基金supported by the National Key Research and Development Program of China(2021YFB2800902)National Natural Science Foundation of China(61931010,62225110)Hubei Province Key Research and Development Program(2020BAA006).
文摘Speckle patterns generated by the intermodal interference of multimode fibers enable accurate broadband wavelength measurements.However,the measurement speed is limited by the frame rate of the camera that captures the patterns.We propose a compact and cost-effective ultrafast wavemeter based on multimode and multicore fibers,which employs spectral-spatial-temporal mapping.The speckle patterns generated by multimode fibers enable spectral-to-spatial mapping,which is then sampled by a multicore fiber into a pulse sequence to implement spatial-to-temporal mapping.A high-speed single-pixel photodetector is employed to capture the pulse sequence,which is analysed using a multilayer perceptron to estimate the wavelength.The feasibility of the proposed wavelength estimation method is experimentally verified,achieving a measurement rate of 100 MHz with a resolution of 2.7 pm in a 1 nm operation bandwidth.
基金the National Natural Science Foundation of China(Grant No.62075074)the National Key R&D Program of China(Nos.2018YFF01011800 and 2018YFB2201901).
文摘With the benefits of low latency,wide transmission bandwidth,and large mode field area,hollow-core antiresonant fiber(HC-ARF)has been a research hotspot in the past decade.In this paper,a hollow core step-index antiresonant fiber(HC-SARF),with stepped refractive indices cladding,is proposed and numerically demonstrated with the benefits of loss reduction and bending improvement.Glass-based capil-laries with both high(n=1.45)and low(as low as n=1.36)refractive indices layers are introduced and formatted in the cladding air holes.Using the finite element method to perform numerical analysis of the designed fiber,results show that at the laser wavelengths of 980 and 1064 nm,the confinement loss is favorably reduced by about 6 dB/km compared with the conventional uniform cladding HC-ARF.The bending loss,around 15 cm bending radius of this fiber,is also reduced by 2 dB/km.The cladding air hole radius in this fiber is further investigated to optimize the confinement loss and the mode field diameter with single-mode transmission behavior.This proposed HC-SARF has great potential in optical fiber transmission and high energy delivery.
文摘The time delay （TD） signature is a critical parameter in optical chaos-based applications. The feasi- bility of extracting the TD has been a crucial issue that significantly influences the performance of these applica- tions. In this paper, statistical analyses have been conducted to extract the TD signatures from different types of coupled optical chaos systems. More specifically, a mutually coupled semiconductor laser chaotic system, an intensity-coupled electro-optic chaotic system, and a phase-coupled electro-optic chaotic system are studied in detail. These systems are proposed to resist the attack strategies against the TD signature. They are proved to be effective under statistical analyzes, such as the self- correlation fimction （SF） and mutual information （MI）. However, only a single output has been considered for the attack process in the existing research. We demonstrated that the TD signature can still be extracted by analyzing the mutual statistical relationship between the different output signals which are generated simultaneously by the coupled system. Furthermore, we find that the extraction strategy is effective for a wide parameter range in these schemes.
