- 标题
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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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Analysis of optical injection on red and blue laser diodes for high bit-rate visible light communication
摘要： In this work, self-injection and external-injection in ～450 nm InGaN/GaN blue and ～650 nm InGaP/AlGaInP red diode lasers are investigated. A distinct locking characteristic is observed in the self-injection case with small 19 cm cavity length, demonstrating enhanced ～2.34 and ～2.07 GHz 3-dB bandwidths, corresponding to a factor of ～1.4 and ～1.1 improvement, and reduced ～60 and ～80 pm spectral linewidths, for the blue and the red lasers, respectively. Moreover, this short external cavity self-injection locked system exhibited superior performance by a factor of 1.1–1.3 compared to the long cavity (26 cm) configuration. Conversely, the external optical injection exhibited weak locking signature with improved linewidths by a factor of ～1.6–2.8 and reaching as small as ～70 and ～87 pm for the blue laser, respectively, while almost doubling in the peak powers. Later, on–off keying modulation technique based data transmission rates of up to 3.5 and 4.5 Gb/s are demonstrated on free-running blue and red laser diodes, respectively, employing an in-house laser diode mount based system. Moreover, owing to the bandwidth limitation of the optically injected systems, successful transmission of up to 2 Gb/s is demonstrated with better performance compared to the respective free-running cases, in particular, the external-optically injected system demonstrated more than double improvement in the bit-error-rate.
关键词： Visible light communication,Semiconductor laser diodes,External optical injection,Self-injection locking
更新于2025-11-28 14:23:57
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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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[IEEE 2019 International Conference on Advances in Computing and Communication Engineering (ICACCE) - Sathyamangalam, Tamil Nadu, India (2019.4.4-2019.4.6)] 2019 International Conference on Advances in Computing and Communication Engineering (ICACCE) - Estimation of maximum range for underwater optical communication using PIN and avalanche photodetectors
摘要： This paper presents an estimate of underwater optical communication (UWOC) range, using PIN and avalanche photodetectors (APDs). In this simulation-based study, the maximum range while transmitting high-quality video at 6Mbps speed is estimated as 520m in Pure Sea water, 65m in Clear Ocean and 44m in Coastal waters, when using a 100mW laser and APD. The channel here is modeled to include the effect of attenuation and noise. This work quantifies the benefits of using an adaptive system where the wavelength (blue, blue-green and green) of transmission and modulation scheme is changed based on water transmission. Wavelength adaptation according to varying water transmission was found to provide 16 to 40dB advantage in SNR, compared to a system with fixed wavelength, in different waters. A recommendation for wavelength adaptable transmitter design is made based on this. This study assumes the current state of the art in commercially available components.
关键词： Laser,photodetector,underwater communication,range,attenuation
更新于2025-11-14 15:24:45
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Photonic generation of high-purity 60?GHz millimeter-wave signal requiring only 10?GHz radio frequency local oscillator
摘要： A novel approach to generate 60 GHz millimeter-wave from a 10 GHz radio frequency signal using an integrated nested DD-MZM without optical filter is proposed and demonstrated. The simulation results show that the generated frequency sextupling optical mm-wave has high purity with an OSSR exceeding 29 dB and a RFSSR of 25 dB, which is consistent with the theoretical analysis. Besides, a RoF link model is established to investigate the transmission performance. The eye diagram keeps clear even when the optical mm-wave is transmitted over 60 km and the power penalty is about 0.4 dB after fiber transmission of 50 km.
关键词： Optical fiber communication,Dual-drive Mach–Zehnder modulator (DD-MZM),Optical millimeter-wave generation
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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Communicating the spatiotemporal transformation of architectural heritage via an in-situ projection mapping installation
摘要： Understanding the spatial transformation of architectural heritage over time is crucial for documentation and conservation purposes, but also for communicating the salient architectural features of the buildings’ evolution to the public at large. With the rapid evolution of physical computing technologies such as electronics, sensors and digital projections, we believe that the technique of projection mapping offers great potential in communicating heritage in-situ because its graphical depiction on the heritage itself can more directly relate to the real context in more experiential ways. Furthermore, digital projections can include various interactive functionalities that together with its architectural size provide an immersive experience that is dynamic and adaptable to the interests of the visitors. Consequently, this paper aims to investigate the deployment of an interactive projection mapping installation in-situ which can be steered by a tangible user interface (TUI). Through an in-the-wild study, we deployed a mixed-method evaluation to investigate how such an interactive projection mapping enhances the communication of the spatiotemporal transformation of a medieval chapel that occurred during the last 850 years. Our findings show how the in-situ projection positively affects visitors’ understanding and memorability of the aesthetic features, and how its combination with a tangible interface enhances the communication of the spatial features of the chapel over time, and allows for more social interaction among them. The paper concludes with several discussion points and recommendations for applying interactive projection mapping and TUIs in the context of architectural heritage.
关键词： Spatiotemporal transformation,Tangible user interface (TUI),Heritage communication,Architectural heritage,Projection mapping,In-situ installation
更新于2025-09-23 15:23:52
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[Lecture Notes in Computer Science] Distributed Computing and Internet Technology Volume 11319 (15th International Conference, ICDCIT 2019, Bhubaneswar, India, January 10–13, 2019, Proceedings) || Improved Visible Light Communication Using Code Shift Keying Modulation
摘要： Visible light communication can provide higher bandwidth and bit rates without causing any interference to the Radio Frequency signals. Red-Green-Blue Light-Emitting Diodes are more suitable than other light sources as they have a smaller switching time, greater lifespan and cost-effective. Designing a communication scheme that avoids dimming and flickering, and that maximize the throughput and coverage area is challenging. Modulation schemes such as Amplitude Shift Keying, Frequency Shift Keying, and Phase Shift Keying exist in the literature for communication with controlled dimming and flickering effect. However, these schemes may not be efficient as they bound the bit rates with more Bit Error Rate. In this paper, a spread spectrum technique, Code Shift Keying along with Manchester (CSK-M) coding, is used to improve bit rates, a reduction in Bit Error Rate with an efficient control of fluctuations and dimming effect. The simulation results show that the presented approach outperforms the existing modulation schemes.
关键词： Visible light communication,Dimming,Bit rate,BER,CSK-M
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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Visible Light Communication based Vehicle-to-Vehicle Tracking using CMOS Camera
摘要： This study presents a visible light-communication-based vehicle-to-vehicle tracking system using a new positioning algorithm and modified version of the Kalman filter. In this system, LED head and tail lamps on the vehicles are used to transmit positioning signals to other vehicles. Two CMOS dashboard cameras on each vehicle are used to receive these signals. From the geometric relationship between two cameras and the images of LEDs captured by these two cameras, the instantaneous position of the target vehicle can be determined given that at least one LED of the target vehicle is in the view frame of the two cameras. The discrete positioning result always contains unavoidable errors, which consist of systematic errors caused by the CMOS rolling shutter artifact and the weak spatial separability of the sensor, and other random errors. The contribution of this paper is twofold. First, a new positioning algorithm with two compensation mechanisms is proposed to eliminate systematic errors. Second, a modified Kalman filter is proposed to filter out random errors to achieve a smooth and accurate tracking result for the vehicle position. The performance of the system is verified through simulations.
关键词： tracking,vehicle,Kalman filter,visible light communication,camera
更新于2025-09-23 15:23:52