We report a high-performance EML integrated on an AlN sub-mount using flip-chip technology. It is capable of high-speed modulation, demonstrating 3-dB bandwidth at 110 GHz, low TDECQ values of 1.9 dB, and an extinction ratio of 4.8 dB for 113 GBaud-PAM4. (c) 2025 The Author(s)
We propose a high-power REC-DFB laser array with wide waveguides and integrated phase compensators, enhancing single-mode yield and wavelength precision. The slab-coupled optical waveguide improves output power, reduces resistance, and minimizes far-field divergence, achieving >100 mW power, >50 dB SMSRs, and high uniformity for optical I/O systems. (c) 2025 The Author(s)
Fiber sensing holds potential for global environmental monitoring and cable supervision, provided that compatibility with conventional network architectures and ability to localize and interpret events autonomously are demonstrated. We show our progress on these aspects, based on years-long fiber sensing data analysis in real environments. (c) 2025 The Author(s)
We report a dual-tone source on thin-film lithium niobate for generating a tunable carrier frequency in the terahertz domain. The system achieves a stable carrier above 100 GHz, with sub-KHz linewidth and tunability over 5 GHz, offering a compact solution for integrated terahertz photonic systems.
We propose and validate a post-processing method that removes CO2 absorption in hollowcore fibres and establishes internal overpressure, enabling stable, contamination-resistant, reliable C+L band transmission across kilometre-scale cables for multiband optical networks. (c) 2025 The Author(s)
We present the implementation and demonstration of a contention-less 19-core spatial cross-connect using packaged core-selective switches and core-port selectors. The system enables core contention-free, per-core routing and add/drop functionality, significantly simplifying spatial channel establishment in spatial channel networks. (c) 2025 The Authors
We propose a machine learning based framework for proactive EDFAs' gain degradation detection and localization in digital coherent receivers. The framework is experimentally validated using optical links with different number of inline-EDFAs present and the results show over 90% accuracy in localizing the faulty EDFAs. (c) 2025 The Author(s)
We demonstrate frequency comb generation in a 108 GHz-FSR SiC microresonator using an obliquely polarized pumping. A portion of the pump couples to an orthogonally polarized auxiliary mode for thermal compensation, enabling stable generation of broadband single soliton microcombs.
We demonstrate novel broadband variable-confinement semiconductor optical amplifiers featuring longitudinal tapering of the device cross-section to provide gain levels around 27 dB, saturation output power up to 18 dBm and low noise figure under 6 dB in the S-band. (c) 2025 The Author(s)
We report on O-band InAs/GaAs QD DFB laser with integrated SOA section, able to deliver more than 400 mW optical power with efficiency beyond 20% in 25-85 degrees C temperature range. This laser is perfectly suited for uncooled operation in ELS for CPO. (c) 2024 The Author(s)
By analyzing the noise power dependence on symbol rate in the discrete eigenvalue transmission, the optimal symbol rate the minimizes the noise power is analytically found to be low, and the possible gain of advanced equalization algorithm is characterized. (c) 2025 The Author(s)
A novel frequency-chirped amplitude-modulated continuous-wave LiDAR for eliminating dependency on light-intensity modulation devices is presented. Leveraging a nonlinear optical-frequency-swept MEMS-VCSEL and a fiber-based MZI, tunable frequency-chirped depth is achieved with better than 3.73-mm ranging accuracy and 5.50-mm precision, reducing system complexity for scalable high-performance ranging. (c) 2025 The Author(s)
We demonstrate longitudinal power monitoring over a 302-km link with a record 40-m spatial resolution, achieving 7.5x10(3) distance dynamic range. Losses and power variations within nodes, including intra-office losses at patch-panel connectors, are visualized and localized from the link endpoint using a coherent receiver. (c) 2025 The Author(s)
We propose a straggler-aware resource allocation in semi-decentralized federated learning for large-scale machine-learning models over OTNs. Simulations show it achieves only 2.55% gap to MILP while reducing runtime by 99.78%, and outperforms the SoTA heuristic with 7% higher task success rate and 41% less runtime. (c) 2025 The Author(s)
We demonstrate a 0.534p non-volatile, reversible phase shift in an asymmetric Mach-Zehnder interferometer with 400-mu m-long Si-rich SiN phase shifters by UV irradiation and micro-heater heating. By increasing Si dangling bonds and heating temperature, we achieve a 2.5-fold effective refractive index change compared to N-rich SiN. (c) 2025 The Author(s)
We propose the node structure, network service and strategy to enable re-grouping flexibility of DSCM P2MP. We demonstrate the re-grouping use cases, acheiving the fault recovery without service loss and the dynamic adaptation to the various day-night traffic over a metro-access integration ring network. (c) 2025 The Author(s)
An ultracompact low-loss embedded rhomboidal segmented Sb2Se3 nonvolatile phase shifter is proposed and implemented, achieving phase modulation up to similar to 0.37 pi mu m(-1) and low loss at similar to 0.017 dB mu m(-1), and 15 phase levels controlled by direct writing laser. (c) 2025 The Author(s)
Using only blind equalization schemes, we demonstrate 2 Tb/s/lambda 3-mode transmission over a 54-km few-mode fiber. Digital subcarrier multiplexing is used to limit the required per-subcarrier MIMO length allowing the utilization of blind equalization with singularity-free convergence. (c) 2025 The Author(s)
Using low-power, eye-safe vertical-cavity surface-emitting lasers (VCSELs) in combination with passive spiral phase plates (SPPs), we experimentally demonstrate a compact and cost-effective orbital angular momentum (OAM)-multiplexed optical wireless communication (OWC) link. The system achieves an aggregate data rate of 75 Gbps over a 1-meter distance.
A 650 nm LED integrated within ONU optics for visual fault location purpose is used to transmit data. ONU serial number is transmitted over up to 6 km at 18 bit/s and detected by a simple smartphone back camera. (c) 2025 The Author(s)
