- 标题
- 摘要
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- 实验方案
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A single-longitudinal-mode narrow-linewidth dual-wavelength fiber laser using a microfiber knot resonator
摘要： A stable narrow-linewidth dual-wavelength single-longitudinal-mode (SLM) erbium-doped fiber laser is demonstrated using a microfiber knot resonator (MKR). A MKR made by the microfiber knotting method exhibits the characteristics of flexibility, high quality factor and broad free spectral range and can be used as a comb-like ultra-narrow band pass filter. SLM operation of the fiber laser can be generated as a function of the Vernier effect by cascading a 650 μm diameter MKR in the ring cavity. In combination with a common fiber Bragg grating, narrow linewidths (0.016 nm and 0.019 nm) of dual wavelength are generated. Finally, a SLM ring laser with narrow linewidth and low-frequency noise is achieved. Simultaneous generation of first- and second-order optical vortex beams in the dual-wavelength fiber laser using different mode-selective couplers is demonstrated.
关键词： fiber lasers,fiber optics,optical communication
更新于2025-11-28 14:24:03
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[IEEE 2018 International Applied Computational Electromagnetics Society Symposium - China (ACES) - Beijing, China (2018.7.29-2018.8.1)] 2018 International Applied Computational Electromagnetics Society Symposium - China (ACES) - Dual-polarization ultra-thin tunable AMC surface for P/L bands applications
摘要： A dual-wavelength laser diode (DWLD) with a novel structure for optoelectronic applications is presented. The device operates at 1550 nm and 1310 nm wavelengths, achieving high output power and stable performance. Experimental results demonstrate its potential for use in optical communication systems.
关键词： 1310 nm,optical communication,1550 nm,dual-wavelength laser diode,optoelectronics
更新于2025-11-28 14:23:57
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An 82-m 9 Gb/s PAM4 FSO-POF-UWOC Convergent System
摘要： With the increasing demands in free-space/underwater environmental monitoring, disaster precaution, and manufacturing industry applications, free-space optical (FSO)-plastic optical fiber (POF)-underwater wireless optical communication (UWOC) convergence is designed to be a promising framework for providing long-haul free-space with underwater links. An 82-m 9 Gb/s four-level pulse amplitude modulation (PAM4) system employing a 405-nm blue-light injection-locked laser diode (LD) is thereby offered and practically demonstrated. Results reveal that a 1.8-GHz 405-nm blue-light injection-locked LD can be effectively applied for a 9 Gb/s PAM4 signal transmission over 50 m FSO link, 30 m graded-index (GI)-POF transportation, and 2 m clear ocean underwater channel. To the authors’ understanding, this study is the first to practically build an 82-m 9 Gb/s PAM4 FSO-POF-UWOC convergent system that effectively constructs a long-haul optical wireless-wired-wireless link using doublet lenses, GI-POF, and optical beam reducer. The performances of the proposed convergent systems are analyzed by bit error rate and non-return-to-zero eye diagram in real-time over an 82-m transport. This framework is the leading one to establish a long-haul FSO-POF-UWOC convergent system with qualified transmission performances. It guides a promising way to facilitate wide applications in the convergence of FSO, POF and UWOC.
关键词： Graded-index plastic optical fiber,Underwater wireless optical communication,Four-level pulse amplitude modulation,Free-space optical
更新于2025-09-23 15:23:52
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Datasets on extinction coefficients for free space optical link survey and optimization
摘要： Based on visibilities data recorded from 2004 to 2013, the minimum, maximum and mean values of extinction coefficients were determined and analyzed in a monthly basis, a yearly basis and also for the whole period of observation. The extinction coefficients data are obtained for the 1330 and 1550 nm optical wavelengths and may be used inter alia for range and availability analyses of optical link for different weather conditions. The data are collected in the region of Dakar, but approach and model of investigation can be reproduced for other regions in Sahel, and in the World, for optical metrology and allied fields of study.
关键词： Optical signal metrology in atmosphere,Free Optical communication
更新于2025-09-23 15:23:52
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Temperature dependence simulation and characterization for InP/InGaAs avalanche photodiodes
摘要： Based on the newly proposed temperature dependent dead space model, the breakdown voltage and bandwidth of InP/InGaAs avalanche photodiode (APD) have been investigated in the temperature range from -50°C to 100°C. It was demonstrated that our proposed model is consistent with the experimental results. Our work may provide a guidance to the design of APDs with controllably low temperature coefficient.
关键词： separate absorption, grading, charge, and multiplication avalanche photodiode (SAGCM APD),optical communication,temperature coefficient,dead space effect
更新于2025-09-23 15:23:52
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[IEEE 2018 International Conference on Current Trends towards Converging Technologies (ICCTCT) - Coimbatore, India (2018.3.1-2018.3.3)] 2018 International Conference on Current Trends towards Converging Technologies (ICCTCT) - Impact of Modulation Techniques for Hybrid-WDM Based FSO
摘要： Free space optical communication (FSO) provides high data rate by allowing light passed through the atmosphere. It is very effective and efficient technology for wireless communication. This emerging field basically uses invisible beams of light such as ultraviolet, infrared, etc. This work exclusively deals with the designing of hybrid WDM based FSO system using the simulation software Opti-System 7.0 with Minimum-Shift Keying and Differential-phase-shift keying. Further their study has been made as to which modulation techniques provides better means of communication. The normal rain weakening from rain power information which are gathered for a period for six months. The concert of the future system is evaluated in terms of Bit Error Rate, Q-factor, and Receiver Sensitivity are examined with respect to link distance for using rain attenuation 20.5dBm. The transmission wavelength and data rate is 1550nm and 2.5Gbps considered for investigation.
关键词： Receiver Sensitivity,Hybrid WDM,BER,Free space optical communication,DPSK,MSK
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE 3rd Optoelectronics Global Conference (OGC) - Shenzhen (2018.9.4-2018.9.7)] 2018 IEEE 3rd Optoelectronics Global Conference (OGC) - Signal Quality Improvement in Optical PPM-CDMA Systems Based SIC Scheme
摘要： Optical pulse position modulation-code division multiple access (PPM-CDMA) system with an interference theoretically analyzed. Successive interference cancellation (SIC) scheme has the ability to suppress the overlapping between the users by subtracting the strongest one from the original received signals one by one until all users detected. Different optical codes have been used for the comparison purpose; results show that the system with SIC scheme using modified quadratic congruence codes has better performance than the system using modified prime code as signature codes. In addition, the system with SIC scheme significantly superior to the one without SIC scheme.
关键词： code division multiple access,optical communication,interference cancellation,pulse position modulation
更新于2025-09-23 15:22:29
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Modeling of Short-Range Ultraviolet Communication Channel Based on Spherical Coordinate System
摘要： The study on short-range ultraviolet (UV) communication (UVC) channel modeling is often based on prolate-spheroidal coordinate system in previous studies. In this letter, we propose a single scattering coplanar model based on spherical coordinate system, where the transmitter beam and receiver field of view (FOV) can point arbitrarily under the limitation that the sum of transceiver elevation angles and half of their own FOV is less than 180°, and the transmitter beam and receiver FOV are above ground. We utilize the number of intersections between a special ray on the transmitter cone and the receiver conical surface to distinguish the UVC scenarios, which makes the analysis of UVC channel modeling comprehensible. Meanwhile, we validate the proposed model in comparison with the single scattering model and the Monte Carlo simulation model through numerical calculations. The results show that the proposed model agrees well with the both models. This work presents a new method to estimate the path loss of short-range UVC and provides guidelines for the experimental system design.
关键词： ultraviolet communications,Atmospheric propagation,free-space optical communication
更新于2025-09-23 15:22:29
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A Pilot Symbols Aided Adaptive Kalman Filter for Joint Carrier Phase and Polarization Tracking in Coherent Optical System
摘要： A joint compensation scheme based on pilot symbols aiding adaptive Kalman filter (AKF) for phase noise and polarization cross-talk is proposed and investigated via numerical simulation and experimental demonstration. In the proposed scheme, the optimizing parameter Q is adaptively adjusted according to signal parameters or channel conditions. This improvement avoids the drawback of conventional extended Kalman filter (EKF), and its performance is strongly dependent on Q. Another improvement is that the convergence speed of AKF is improved. Pilot quadrature phase shift keyin (QPSK) symbols are inserted into 16 quadrature amplitude modulation (QAM) signals periodically. Besides accelerating convergence speed, the employment of pilot symbols also improves the tracking capability of AKF. The format ratio between pilot symbols and payload symbols is suggested under different system environments, for instance, optical signal-to-noise rate, polarization rotation frequency drift rate, and laser linewidth. With the proposed scheme, it has excellent tolerance to initial parameter Q and dramatically improves the performances in convergence speed, polarization rotation frequency drift rate tracking, and carrier phase recovery. Both the numerical simulation and experimental demonstration achieve convergence improvement for around 40 times than the original AKF. Additionally, the improvements in tracking ability are also demonstrated.
关键词： dynamic polarization rotation,pilot aided adaptive Kalman filter,phase noise,coherent optical communication
更新于2025-09-23 15:22:29
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Performance Analysis of Kramers-Kronig Receiver in the Presence of IQ Imbalance
摘要： We investigate the impact of IQ imbalance of the transmitter on the performance of the direct-detection system utilizing the Kramers-Kronig receiver. We show through theoretical analysis that the amplitude imbalance, timing misalignment, and IQ phase mismatch create double-sideband distortions, which, in turn, serve to violate the minimum phase condition and also lead to the dispersion-induced RF power fading after transmission. The theoretical analysis is verified by using numerical simulations. The results show that the amplitude imbalance and timing misalignment should be less than 2 dB and 2 ps, respectively, when the receiver sensitivity penalty is smaller than 1 dB for the transmission of 112-Gb/s 16-QAM OFDM signal.
关键词： direct detection,optical communication,optical modulation
更新于2025-09-23 15:21:21