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- 摘要
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[IEEE 2018 European Conference on Optical Communication (ECOC) - Rome, Italy (2018.9.23-2018.9.27)] 2018 European Conference on Optical Communication (ECOC) - Ultra-Short Wavelength Operation of Thulium-Doped Fibre Amplifier in the 1628–1655nm Waveband
摘要： We present a silica-based thulium-doped fibre amplifier in the 1628-1655nm waveband based on Tm/Ge co-doped fibre. Up to 19dB external small signal gain and a noise figure of 4.4dB are achieved at 1655nm.
关键词： silica-based,Tm/Ge co-doped fibre,ultra-short wavelength operation,optical communications,thulium-doped fibre amplifier
更新于2025-11-28 14:24:03
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Stable injection locking with slotted Fabry–Perot lasers at 2 <i>μ</i> m
摘要： Injection locking has many applications in telecommunications systems, such as narrowing linewidths, increasing bandwidth and improving filtering. Beyond telecommunications, injection locking is widely used in remote sensing. This is of particular interest for applications in the 2 μm region, where gases such as carbon dioxide, water vapour and methane have identifiable absorption features. In this paper, we demonstrate stable injection locking with slotted Fabry–Perot lasers in the 2 μm wavelength region. Injection locking was observed in both the optical domain and power spectrum; with key features recorded such as injection ‘pulling’, side-mode suppression and the characteristic quiet region in the electrical domain denoting single-frequency emission and stable locking. The effect of varying the injection ratio was investigated, with a decreased injection ratio corresponding to a reduction in the locking bandwidth. Finally, the lasers were shown to remain injection locked, with no thermal drift, for over 24 h, indicating their suitability for implementation in a real-world telecommunications system.
关键词： injection-locked lasers,semiconductor lasers,optical communications,optical sensing and sensors
更新于2025-11-28 14:23:57
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Approaching Terabits per Carrier Metro-Regional Transmission Using Beyond-100GBd Coherent Optics with Propabilistically Shaped DP-64QAM Modulation
摘要： This research work proposed and experimentally demonstrated beyond-100GBd probabilistically-shaped coherent optics that support transmission of ~1.2 Tbps coded line rate and ~0.9 Tbps net bit rate per optical carrier over metro-regional distances. Pursuing next-generation transmission systems having both high capacity approaching Terabits per wavelength and high spectral efficiency requires engineering efforts from different aspects, which may includes the enhancement of analog-to-digital or digital-to-analog (AD/DA) interfaces, the improvement of channel characteristics, and also the realization of better receiver sensitivities, preferably through DSP techniques such as probabilistic shaping (PS). By doing so, this work achieved single-channel and 112.5GHz-WDM transmission of 900G wavelengths over 800 km and 400 km, respectively, which employed PS DP-64QAM modulation format at 105 GBd, yielding a net spectral efficiency of 8.05 bits/s/Hz. Such a high symbol rate was demonstrated using a commercially available DAC unit without band-interleaving. The enhanced optical channel consists of ITU-T G.654 compliant Terawave SLA+ fiber spans with backward-pumped Raman amplifiers. In addition, with the same PS DP-64QAM modulation format and the same enhanced channel, this research work also demonstrated that 400G wavelengths can be delivered over 2,800 km supporting long-haul applications.
关键词： quadrature amplitude modulation,probabilistic shaping,optical fibers,Coherent optical communications
更新于2025-09-23 15:23:52
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Performance of Bandwidth Extension Techniques for High-Speed Short-Range IM/DD Links
摘要： In recent years, advanced modulation formats for short-range high-speed communications have been increasingly discussed to achieve the transmission rates needed to satisfy the future demand of broadband services. A key parameter in such applications is the use of low-cost optical components, which mainly means the use of intensity modulation (IM) and direct detection (DD) schemes. In order to exploit the available bandwidth offered by the latest optical components, high-speed data converters (DAC and ADC) are required. However, the available bandwidth of DACs and ADCs is generally smaller, than that of their optical counterparts, resulting in a capacity bottleneck. This issue can be addressed by bandwidth extension techniques, which enable the full use of the optical components. In this paper, two high-speed systems are presented and experimentally analyzed for an optical link based on IM/DD, utilizing a bandwidth extension technique based on electrical up/down-conversion and passive signal combining. The experiment for the first system uses two independent sub-signals, with a total bandwidth beyond 40 GHz and enables transmission rates up to 180 Gb/s. Different aspects of the system are highlighted including general performance, transmission distance, use of different modulation formats and the influence of important components. For the second system, the experiment consists of the generation of a spectrally continuous pulse amplitude modulation (PAM) signal with the help of two sub-signals and its transmission over an optical IM/DD link. The challenges and requirements for hardware and software are discussed and the impact of power and phase mismatches between both sub-signals are investigated as well.
关键词： Fiber optics and optical communications,Fiber optics links and subsystems
更新于2025-09-23 15:23:52
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Dispersion flattened extremely high-birefringent kagome lattice elliptic core photonic crystal fiber in THz regime
摘要： A highly birefringent elliptic porous-core photonic crystal fiber with kagome lattice cladding has been presented for terahertz (THz) wave transmission. The slotted airholes inside the elliptic core effectively disrupt the symmetry of the porous-core which offers extremely high modal birefringence whereas the kagome cladding structure results in significantly low effective material loss (EML). The birefringence of the proposed structure is 9.73 × 10?2 for y-polarized mode at an operating frequency of 1 THz. The suggested structure also provides very flat dispersion over a bandwidth of 300 GHz. It is highly expected that this elliptic core waveguide would be remarkably useful in numerous polarization maintaining THz applications.
关键词： Photonic crystal fibers,Microstructured fibers,Fibres, polarization-maintaining,Optical communications,Fiber design and fabrication
更新于2025-09-23 15:23:52
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Self-synchronized Encryption for Physical Layer in 10Gbps Optical Links
摘要： in this work a new self-synchronized encryption method for 10 Gigabit optical links is proposed and developed. Necessary modifications to introduce this kind of encryption in physical layers based on 64b/66b encoding, such as 10GBase-R, have been considered. The proposed scheme encrypts directly the 64b/66b blocks by using a symmetric stream cipher based on an FPE (Format Preserving Encryption) block cipher operating in PSCFB (Pipelined Statistical Cipher Feedback) mode. One of the main novelties in this paper is the security analysis done for this mode. For the first time, an expression for the IND-CPA (Indistinguishability under Chosen-Plaintext Attack) advantage of any adversary over this scheme has been derived. Moreover, it has been concluded that this mode can be considered secure in the same way of traditional modes are. In addition, the overall system has been simulated and implemented in an FPGA (Field Programmable Gate Array). An encrypted optical link has been tested with Ethernet data frames, concluding that it is possible to cipher traffic at this level, getting maximum throughput and hiding traffic pattern from passive eavesdroppers.
关键词： self-synchronous encryption,Optical Communications,Ethernet,Pipeline Statistical Cipher Feedback
更新于2025-09-23 15:23:52
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An optical wireless communication system deploying active high-pass pre-emphasis circuit for high speed application
摘要： This article presents a high-speed optical wireless communication link with a newly proposed pre-emphasis circuit to increase transmission performance at higher data rates. The effectiveness of the pre-emphasis circuit has been verified through testing on an optical wireless link implemented with existing laser communications components in our laboratory operating at 1550 nm. When the proposed pre-emphasis circuit is included in the optical wireless link, we achieved bit-error-rate (BER) power penalty improvements of 1.6, 2.2, and 1.0 dB at 155 Mbps, 622 Mbps, and 1.244 Gbps, respectively at the BER of 2 × 10?3 compared with the optical wireless communication links without pre-emphasis circuit. For the lower BER of 10?9, BER power penalty improvements of 2.2, 3.7, 0.7 dB at 155 Mbps, 622 Mbps, and 1.244 Gbps are observed, which show the effectiveness of our proposed pre-emphasis circuit in optical wireless communications link.
关键词： pre-emphasis,optical communications,optical wireless communications,free space optical communications,optical wireless link
更新于2025-09-23 15:22:29
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[IEEE 2018 Iranian Conference on Electrical Engineering (ICEE) - Mashhad (2018.5.8-2018.5.10)] Electrical Engineering (ICEE), Iranian Conference on - The Proposal of New Fano Structure for Optical Switching Applications
摘要： In this paper, an improved Fano device for optical switching purposes is designed. Proposed structure has better transmission characteristics in terms of quality factor, loss and switching contrast than previous structures announced in the literature. Results show that the Q contrast of the cavities leads to the better performance of the Fano switch.
关键词： Optical Communications,Photonic Crystal,All optical switching,Fano shape spectrume,Fano Structure
更新于2025-09-23 15:22:29
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[IEEE 2018 20th International Conference on Transparent Optical Networks (ICTON) - Bucharest (2018.7.1-2018.7.5)] 2018 20th International Conference on Transparent Optical Networks (ICTON) - Generation of mmWave 5G Signals Using Microwave Photonics
摘要： Bandwidth constraints is, nowadays, a mayor problem in the implementation of next generation 5G networks. In order to cope with increasing bandwidth demands, the use of the millimeter-wave (mmWave) spectrum, together with Radio over Fiber (RoF) technology has been proposed. In this work, we will present our recent advances in the generation of mmWave signals for 5G using Microwave Photonics.
关键词： microwave photonics,mobile optical communications,radio over fiber
更新于2025-09-23 15:22:29
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Characterization of a Low-Cost, Monolithically Integrated, Tunable 10G Transmitter for Wavelength Agile PONs
摘要： Dynamically reconfigurable passive optical networks (PONs) using time-division multiplexing and dense wavelength division multiplexing will require low-cost, high-performance customer premises equipment to be economically viable. In particular, substantial cost savings can be achieved through the use of efficient re-growth free, foundry-compatible fabrication techniques. Using this strategy, this paper presents the first detailed characterization of a monolithically integrated transmitter comprised of a discretely tunable slotted Fabry–Pérot ridge waveguide laser, an absorptive modulator and a semiconductor optical amplifier (SOA) produced using a standard off-the-shelf AlInGaAs/InP multiple quantum well epitaxial structure. This first generation device demonstrates a discrete single-mode tuning range of approximately 12 nm between 1551nm and 1563 nm with a side-mode suppression ratio ≥30 dB. Moreover, the integrated modulator section is shown to support transmission at 10 Gb/s using non-return to zero on-off keying with an extinction ratio in excess of 8 dB. Furthermore, using a time-resolved chirp measurement technique to examine dynamic deviations in the set carrier frequency, the modulator section exhibits a chirp contribution of <6 GHz using test patterns with high and low frequency content. In addition, the generation of optical bursts through the application of a gating function to the SOA section was found to shift the unmodulated carrier of a typical lasing mode by ≤8 GHz for gating periods comparable with a typical PON burst durations of 125 μs which are faster than the thermal response time of the transmitter material.
关键词： Optical communications,tunable semiconductor lasers,dense wavelength division multiplexing,passive optical networks,time division multiplexing,monolithic integration
更新于2025-09-23 15:21:01