Integration of quantum key distribution and high-throughput classical communications in field-deployed multi-core fibers.

Quantum key distribution (QKD) is a secure communication method for sharing symmetric cryptographic keys based on the principles of quantum physics. Its integration into the fiber-optic network infrastructure is important for ensuring privacy in optical communications. Multi-core fibers (MCFs), the likely building blocks of future high-capacity optical networks, offer new opportunities for such integration.

Differential mode group delay measurement for few-mode fibers based on cepstrum analysis.

The differential mode group delay (DMGD) among various modes in few-mode fibers (FMFs) is a critical parameter for characterizing FMFs' channels. Therefore, achieving a convenient, fast, and accurate measurement of DMGD across the entire communication band for different modes is essential. In this work, we propose a novel, to the best of our knowledge, cepstrum-based method for DMGD measurement in FMFs.

Enhancing nonlinear compensation efficiency with multi-task neural networks for coherent optical systems.

Traditional nonlinear compensation techniques often involve complex models that introduce significant computational overhead, particularly in high-speed, high-capacity optical communication systems. To address this challenge, we propose a low-complexity nonlinear compensation method based on a multi-task neural network (MT-NN), combined with a complexity-aware mean square error (MSE) and partial grid search optimization for coherent optical communication systems. The proposed framework exploits shared network weights to simultaneously process multiple symbols, thereby reducing redundant computations while maintaining compensation accuracy.

Decoupled digital filtering-enabled simplification and fast convergence of IM/DD system linearization algorithms for strong band-limited power fading channels.

Chromatic dispersion limits practically achievable transmission distances of high data-rate intensity modulation and direct detection (IM/DD) optical transmission systems at C-band. Previously reported IM/DD system linearization algorithms can improve their transmission performances, which are, however, sensitive to the band limitation effect. In this paper, for linearizing IM/DD fiber channels with severe power fading and band-limitation, we propose and evaluate numerically and experimentally a decoupled system linearization scheme called equalization-cascaded multi-constraint iterative algorithm (EC-MCIA) using decoupled, channel partial-aware adaptive digital filters and a multiple constraint iteration algorithm.

Comparative Genomic Screening Identifies Developmental Constraint Loci Underscoring the Phenotypic Evolution of Syngnathids.

Seahorses and their relatives (syngnathids) exhibit remarkable diversity in morphology and function, characterized by their distinctive body shapes and specialized feeding mechanisms. Despite recent advances in uncovering the genetic basis of some traits, the genotype-phenotype map in syngnathids remains incomplete. In this study, we employed forward-genomic approaches and developed a method to enrich for human disease amino acid loci at a genomic scale.

C-mannosyltransferase DPY19L1L-mediated Reissner Fiber formation is critical for zebrafish () body axis straightening.

The successful secretion and assembly of subcommissural organ (SCO)-spondin are crucial for Reissner Fiber (RF) formation and body axis straightening in zebrafish. However, the mechanisms underlying RF formation remain largely unknown. Here, we report that the C-mannosyltransferase (dumpy-19 like 1 like) is expressed in the spinal cord during zebrafish embryonic development.

Solvent/temperature dual-responsive photonic crystal structural-color films through double inverse opal structure.

A solvent/temperature dual-responsive P(NIPAM-AM) hydrogel is proposed. The free energy model of the hydrogel microstructure and the transformation of the properties of the hydrogel chain segment during deformation were further analyzed. The resultant structural-color hydrogel film was applied to on-demand patterning.

Telehealth, medical decisions and new health inequality in China.

Background: The widespread of telehealth has not only improved medical service accessibility and convenience, and has also played an active role in the COVID-19 Epidemic. This suggests that telehealth is becoming increasingly important in both normality and emergency. It is therefore essential to evaluate the use of the technology and its impact on the healthcare system.

Multiplication-free error corrector for partial response equalization in 256-Gb/s PAM4 IM/DD systems.

Partial response equalization (PRE) is a spectral shaping technique that enhances robustness to the inter-symbol interference (ISI) due to bandwidth limitation in the high-speed intensity modulation and direct detection (IM/DD) systems. The simple 1/(1 + ) decoder can be used to decode the PR-equalized signal. However, it suffers from error propagation, leading to performance degradation.

Beyond 200 Gb/s/λ C-band PAM-4 low-latency transmission over 20-km nested antiresonant nodeless fiber.

The rapid growth of modern Internet applications demands ever-increasing transmission capacity and reduced latency in optical interconnect systems utilizing intensity modulation and direct detection (IM/DD). However, the intrinsic limitations of silica-based standard single-mode fiber (SMF) will ultimately be insufficient to meet these escalating demands. The nested antiresonant nodeless fiber (NANF), a newly designed hollow-core fiber, has garnered significant attention as a potential solution to these challenges.

High-fidelity digital-analog hybrid RoF fronthaul link enabled by nonlinear radio signal shaping.

We propose a simple and effective method to enhance the fidelity of radio signals in a digital-analog radio-over-fiber (DA-RoF) system by introducing nonlinearity into the transmitted signal. This nonlinearity is introduced via an arctangent function for radio signal shaping (RSS), while the corresponding tangent function is used for signal recovery. Nonlinear shaping spreads near-zero amplitude signals and compresses far-from-zero ones.

O-band EML and 4-bits DAC enabled 112 GBaud PAM8 transmission over a 10 km SSMF without optical amplifiers.

The increasing traffic of intra-data center networks creates an urgent demand for low-cost and high-speed intensity modulation/direct detection (IM/DD) transmission. In this Letter, we propose a joint scheme combining nonlinear lookup table (NL-LUT) pre-distortion, digital pre-emphasis (DPE), and a digital resolution enhancer (DRE) to achieve high-speed and low-cost IM/DD optical links using a low-resolution digital-to-analog converter (DAC). The NL-LUT and DPE are responsible for the system nonlinear impairments and channel attenuation at high frequency, respectively, while DRE handles the quantization noise (QN) caused by high peak-to-average ratios (PAPRs) and low-resolution DAC.

Low-latency 100 Gb/s PAM-4 PON with a 42.5 dB power budget over the 20 km anti-resonant hollow-core fiber.

The surging growth in data traffic has necessitated the development of higher-speed, lower-latency intensity modulation and direct detection (IM/DD) passive optical networks (PONs) with higher power budgets. To address the inherent limitations of traditional silica-based solid-core fibers, anti-resonant hollow-core fibers have garnered significant attention from both academia and industry. In this Letter, we present an experimental demonstration of 100 Gb/s PAM-4 IM/DD PON transmission over a 20 km anti-resonant hollow-core fiber in the C band, utilizing low-complexity digital signal processing (DSP).

The influence of twinning on the corrosion behavior of AZ31B magnesium alloy.

This study investigates the effect of twinning on the corrosion behavior of AZ31B magnesium alloy using solid solution heat treatment (SHT) and laser shock peening (LSP) techniques. The corrosion characteristics are assessed by scanning electron microscopy (SEM), scanning Kelvin probe force microscopy (SKPFM), zero resistance ammeter (ZRA), scanning vibrating electrode technique (SVET), and electrochemical tests. Results indicate that the twinning region in AZ31B magnesium alloy, enriched with tensile twins induced by laser shock, demonstrates increased corrosion susceptibility.

Weight-adaptive joint mixed-precision quantization and pruning for neural network-based equalization in short-reach direct detection links.

Neural network (NN)-based equalizers have been widely applied for dealing with nonlinear impairments in intensity-modulated direct detection (IM/DD) systems due to their excellent performance. However, the computational complexity (CC) is a major concern that limits the real-time application of NN-based receivers. In this Letter, we propose, to our knowledge, a novel weight-adaptive joint mixed-precision quantization and pruning approach to reduce the CC of NN-based equalizers, where only integer arithmetic is taken into account instead of floating-point operations.

Social Medical Insurances, Choices of Medical Institutions and the 'Siphon Effect' in the Health Service Market: Evidence from 2021 Yangtze River Delta Region of China.

Purpose: The siphon effect in the health service market is notably pronounced in many countries. How to measure and identify the determinants contributing to the siphon effect presents a substantial challenge. This study aimed to analyse the effect of two different social medical insurances, the Basic Medical Insurance System for Urban Employees (BMISUE), and the Basic Medical Insurance System for Urban and Rural Residents (BMISURR), on the siphon effect in the health services market.

Multiplication-free and hardware-efficient baud-rate timing error detector for Nyquist and faster than Nyquist optical IM/DD systems.

Clock recovery (CR) algorithms that support higher baud rates and advanced modulation formats are crucial for short-distance optical interconnections, and it is desirable to push CR to operate at baud rate with minimal computing resources and power. In this Letter, we proposed a hardware-efficient and multiplication operation-free baud-rate timing error detector (TED) as a solution to meet these demands. Our approach involves employing both the absolute value of samples and the nonlinear sign operation to emphasize the clock tone, which is deteriorated by severe bandwidth limitation in Nyquist and faster than Nyquist (FTN) systems.

A novel n-UV convertible colour-tunable emitting oxynitride phosphor: Realization based on Ce -Tb energy transfer.

In the present work, a novel n-UV convertible colour-tunable emitting phosphor was obtained based on the efficient Ce -Tb energy transfer in the Y Al Si O N host. By properly controlling the ratio of Ce /Tb , the colour hue of the obtained powder covered the blue and green regions, under excitation of 365 nm. The steady-state and dynamic-state luminescence measurement was performed to shed light on the related mechanism, which was justified by the electronic dipole-quadrupole dominating the related energy transfer process.

Mode-division-multiplexing self-homodyne coherent transmission over a weakly coupled few-mode fiber for optical interconnections.

Self-homodyne coherent transmission has recently received extensive investigation as a coherent lite candidate for high-speed short-reach optical networks. In this Letter, we propose a weakly coupled mode-division-multiplexing (MDM) self-homodyne coherent scheme using a multiple-ring-core few-mode fiber, in which one of the modes transmits a self-homodyne local oscillator (LO) and the rest are utilized for carrying signals. Multiple rings of index perturbations in the fiber core are applied to achieve low modal crosstalk, allowing the signals and the remote LO to be transmitted independently.

Impact of non-Gaussian noise on GMI and LDPC performance in neural network equalized systems.

In this Letter, the impact of non-Gaussian noise caused by a nonlinear equalizer on low-density parity-check code (LDPC) performance is investigated in a 25-km 50-Gb/s pulse amplitude modulation4 (PAM4) direct detection system. The lookup table (LUT)-based log-likelihood ratio (LLR) calculation method is proposed to enhance the LDPC performance for the non-Gaussian noise case. Compared to the conventional LLR calculation method based on Gaussian distribution, the proposed method can improve 0.

Gradient-descent noise whitening techniques for short-reach IM-DD optical interconnects with severe bandwidth limitation.

Bandwidth limitation in optoelectrical components and the chromatic dispersion-induced power fading phenomenon cause severe inter-symbol interference (ISI) in high-speed intensity modulation and direct detection (IM-DD) optical interconnects. While the equalizer implemented in the receiver's digital signal processing procedure can mitigate ISI, it also inevitably enhances the noise located in the decayed frequency region, known as equalization-enhanced colored noise (EECN). Additionally, the nonlinear impairments of the modulator and photodetector also deteriorate the performance of the IM-DD system, especially for high-order modulation formats.

Proof of Aerobically Autoxidized Self-Charge Concept Based on Single Catechol-Enriched Carbon Cathode Material.

An air-breathing chemical self-charge concept of oxygen-enriched carbon cathode. The oxygen-enriched carbon material with abundant catechol groups. Rapid air-oxidation chemical self-charge of catechol groups.

An ULK1/2-PXN mechanotransduction pathway suppresses breast cancer cell migration.

The remodeling and stiffening of the extracellular matrix (ECM) is a well-recognized modulator of breast cancer progression. How changes in the mechanical properties of the ECM are converted into biochemical signals that direct tumor cell migration and metastasis remain poorly characterized. Here, we describe a new role for the autophagy-inducing serine/threonine kinases ULK1 and ULK2 in mechanotransduction.

Fast polarization state tracking for dual-polarization direct detection with Jones-space field recovery.

Direct detection system is expected to possess the phase and polarization diversity in order to achieve high spectral efficiency and fiber impairment compensation such as chromatic dispersion and polarization rotation. In this Letter, we theoretically extend the concept of the proposed Jones-space field recovery (JSFR) to include a dynamic polarization rotation matrix and experimentally demonstrate the rapid polarization state tracking ability of the JSFR receiver based on a 3 × 3 optical coupler. Under a rotation of the state of polarization at a rate of 1 Mrad/s, we successfully transmit 59-GBd dual-polarization 16-ary quadrature-amplitude-modulation signals over an 80-km standard single-mode fiber based on a decision-directed least mean square (DD-LMS) or a recursive least square (DD-RLS), with a bit-error rate below the 14% hard-decision forward error correction threshold of 1 × 10.