Characteristics of optical switching in a twin-core fibre coupler are numerically analysed under short pulse input by using supermode theory. The dynamic nonlinear coupled superlnode equations are derived, The numeric...Characteristics of optical switching in a twin-core fibre coupler are numerically analysed under short pulse input by using supermode theory. The dynamic nonlinear coupled superlnode equations are derived, The numerical results show that the input pulse width determines the power transfer and the pulse temporal profile in the output ports. The optimal switching characteristics can be obtained by selecting an appropriate initial pulse width. In addition, the switching characteristic curves are insensitive to the input pulse shape for either fundamental soliton pulse or Gaussian pulse input, but sensitive to pulse sharpness. A reduced switching power and a sharper switching transition can be obtained by using the sharp super-Gaussian pulse.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
Suppressing mode degradation is the key issue for high-power laser delivery;however,diagnosing mode degradation in its entirety,ranging from the contents and origins to locations,has always been a major obstacle.Here,...Suppressing mode degradation is the key issue for high-power laser delivery;however,diagnosing mode degradation in its entirety,ranging from the contents and origins to locations,has always been a major obstacle.Here,a versatile approach for tracing the origins of mode coupling is demonstrated through addressing the differential intermodal dispersions of fiber modes.Full recognition for modal contents and the origins of mode degradation are experimentally completed in a two-mode fiber laser delivery system,which assists a significant improvement of beam quality M^(2)from1.35 to 1.15 at the highest power of over 300 W.This method yields a quantitative characterization for manipulating the individual mode of dual-mode coupling origins or their combinations.This work points toward a promising strategy for the online tracing of mode coupling in cascade fiber links,thus enabling further pursuit of seeking extreme beam quality in high-power fiber laser systems.展开更多
基金Supported by the Natural Science Foundation of Guangdong Province （04010397）, and the Excellent Teacher Foundation of Guangdong Province （Q02084）.
文摘Characteristics of optical switching in a twin-core fibre coupler are numerically analysed under short pulse input by using supermode theory. The dynamic nonlinear coupled superlnode equations are derived, The numerical results show that the input pulse width determines the power transfer and the pulse temporal profile in the output ports. The optimal switching characteristics can be obtained by selecting an appropriate initial pulse width. In addition, the switching characteristic curves are insensitive to the input pulse shape for either fundamental soliton pulse or Gaussian pulse input, but sensitive to pulse sharpness. A reduced switching power and a sharper switching transition can be obtained by using the sharp super-Gaussian pulse.
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supported by the National Key Research and Development Program of China(No.2022YFB3606000)the National Natural Science Foundation of China(Nos.12174445 and 62061136013)the State Key Laboratory of Pulsed Power Laser Technology(No.SKL2021ZR06)。
文摘Suppressing mode degradation is the key issue for high-power laser delivery;however,diagnosing mode degradation in its entirety,ranging from the contents and origins to locations,has always been a major obstacle.Here,a versatile approach for tracing the origins of mode coupling is demonstrated through addressing the differential intermodal dispersions of fiber modes.Full recognition for modal contents and the origins of mode degradation are experimentally completed in a two-mode fiber laser delivery system,which assists a significant improvement of beam quality M^(2)from1.35 to 1.15 at the highest power of over 300 W.This method yields a quantitative characterization for manipulating the individual mode of dual-mode coupling origins or their combinations.This work points toward a promising strategy for the online tracing of mode coupling in cascade fiber links,thus enabling further pursuit of seeking extreme beam quality in high-power fiber laser systems.
