Transmission Experiments Research Articles

Real-time full-duplex transmission experiment for air and underwater invisible light communication system

Real-time full-duplex transmission experiment for air and underwater invisible light communication system

Probabilistic shaping probability distribution scrambling based on a chaotic system for integrating secure transmission and adaptive key updating

A probabilistic shaping probability distribution scramble (PSPDS) scheme based on chaotic systems is proposed to fulfill both secure transmission and adaptive key updating. The chaotic Chen and logistic systems are adopted to generate a chaotic random sequence. The probabilistic shaping is achieved by constant composition distribution matching (CCDM) and probabilistic amplitude shaping architecture. The chaotic, random sequences are used to scramble the probability distribution of CCDM, improving security. The session key is embedded into a probability distribution. The legal receiver extracts the error-free session key when OSNR is higher than the requirement of the forward error correction threshold. We employ a coherent OFDM 16QAM transmission experiment on 120 km fiber, confirming our proposed scheme with a net rate of 9.95 Gbit/s. The results show that the PSPDS scheme has no encryption penalty compared with the baseline without encryption. The key updating rate has the ability to vary adaptively and reaches 224.2 Mbit/s by adjusting the block length of CCDM in our experiment. The key space reaches 10136. Even if an illegal party obtains a ciphertext signal, the plaintext and session key can hardly be inferred due to a probability distribution scramble.

Short range optical communication with GaN‐on‐Si microLED and microPD matrices

Abstract(In)GaN microLEDs have reached a high degree of maturity due to their development in the lighting industry. Their robustness and high efficiency make them ideal candidates for high‐brightness, high‐resolution micro‐displays. Beyond display applications, microLEDs are being explored for non‐display uses, including wireless Visible Light Communication (VLC) and parallel communication via multicore fiber. This study investigates short‐range chip‐to‐chip optical communication using InGaN/GaN microLEDs and micro Photodiodes (microPDs). Leveraging processes developed for micro‐displays, we address the challenges of integrating GaN microLEDs and microPDs on ASICs. We outline the main figures of merit, including expected energy efficiency, optical coupling to multicore fibers or waveguides, and the spectral efficiency of InGaN/GaN microPDs correlated with TCAD simulation and experimental transmission results. Our study highlights the potential of GaN microLEDs and microPDs for massively parallel, energy‐efficient data transmission, paving the way for innovative short‐range and energy‐efficient optical communication solutions.

Directional Coupling to a λ/5000 Nanowaveguide.

Silicon-based microdevices are considered promising candidates for consolidating several terahertz technologies into a common and practical platform. The practicality stems from the relatively low loss, device compactness, ease of fabrication, and wide range of available passive and active functionalities. Nevertheless, typical device footprints are limited by diffraction to several hundreds of micrometers, which hinders emerging nanoscale applications at terahertz frequencies. While metallic gap modes provide nanoscale terahertz confinement, efficiently coupling to them is difficult. Here, we present and experimentally demonstrate a strategy for efficiently interfacing subterahertz radiation (λ = 1 mm) to a waveguide formed by a nanogap, etched in a gold film, that is 200 nm (λ/5000) wide and up to 4.5 mm long. The design principle relies on phase matching dielectric and nanogap waveguide modes, resulting in efficient directional coupling between them when they are placed side-by-side. Broadband far-field terahertz transmission experiments through the dielectric waveguide reveal a transmission dip near the designed wavelength due to resonant coupling. Near-field measurements on the surface of the gold layer confirm that such a dip is accompanied by a transfer of power to the nanogap, with an estimated coupling efficiency of ∼10%. Our approach efficiently interfaces millimeter waves with nanoscale waveguides in a tailored and controllable manner, with important implications for on-chip nanospectroscopy, telecommunications, and quantum technologies.

Transmission of grapevine Roditis leaf discolouration-associated virus by the vine mealybug, Planococcus ficus (Signoret) in Turkey

ABSTRACT Grapevine Roditis leaf discolouration-associated virus (GRLDaV) is from Badnavirus decoloratiovitis species, which is a member of the genus Badnavirus, associated with Roditis leaf discolouration disease. Although mealybug transmission of GRLDaV by Planococcus ficus has been demonstrated elsewhere, its role in the transmission has not been shown in different grapevine varieties, isolates, acquisition periods (AP) and inoculation periods (IP). Individiual P. ficus was collected from a vineyard in Adana, Turkey and used for insect culture establishment for the transmission studies. Virus transmission experiments to the Vitis vinifera cv. Yalova Incisi via P. ficus was carried out using a local GRLDaV isolate by applying AP-IP for 24 , 48 h or 72 h. The virus was transmitted by P. ficus in all AP-IP trials (100%, 60%, and 20% of recipient vines infected after 24 , 48 h, and 72 h, respectively). GRLDaV was first detected in the recipient grapevines four weeks after transmission. The results showed that P. ficus transmitted GRLDaV in a semipersistent manner. All the virus infected vines in the experiment showed initial leaf symptoms of yellow vein banding and/or discolouration, followed by yellow and/or reddish discolouration of the leaves in late summer, as observed in GRLDaV-infected vines in the field.

Precise Size Determination of Supported Catalyst Nanoparticles via Generative AI and Scanning Transmission Electron Microscopy.

Transmission electron microscopy (TEM) plays a crucial role in heterogeneous catalysis for assessing the size distribution of supported metal nanoparticles. Typically, nanoparticle size is quantified by measuring the diameter under the assumption of spherical geometry, a simplification that limits the precision needed for advancing synthesis-structure-performance relationships. Currently, there is a lack of techniques that can reliably extract more meaningful information from atomically resolved TEM images, like nuclearity or geometry. Here, cycle-consistent generative adversarial networks (CycleGANs) are explored to bridge experimental and simulated images, directly linking experimental observations with information from their underlying atomic structure. Using the versatile Pt/CeO2 (Pt particles centered ≈2nm) catalyst synthesized by impregnation, large datasets of experimental scanning transmission electron micrographs and physical image simulations are created to train a CycleGAN. A subsequent size-estimation network is developed to determine the nuclearity of imaged nanoparticles, providing plausible estimates for ≈70% of experimentally observed particles. This automatic approach enables precise size determination of supported nanoparticle-based catalysts overcoming crystal orientation limitations of conventional techniques, promising high accuracy with sufficient training data. Tools like this are envisioned to be of great use in designing and characterizing catalytic materials with improved atomic precision.

Observation of widely separated soliton molecules in a mode-locked Yb-doped fiber laser operating with net anomalous dispersion

This paper investigates the generation and characterization of soliton molecules (SM) in a semiconductor saturable absorber mirror (SESAM) mode-locked Yb-doped fiber laser with a linear cavity. By adjusting the pump power, both single-pulsing (SP) and double-pulsing (DP) states can be achieved. The observed soliton molecules are highly stable, with minimal temporal jitter despite being separated by 1.56ns. While SM have been observed in many different cavities this is one of the few reports in a Fabry–Perot cavity rather than a ring cavity and again most previous observations of soliton molecules having been in the anomalous dispersion regime. This configuration thus provides detailed and valuable insights into the behaviour of SM, shedding light on their formation, stability, and dynamics. This study contributes to understanding long range soliton interactions in fiber lasers, with potential implications for applications such as multi-bit transmission, bit storage, and pump-probe experiments to study the dynamics of chemical reactions.

Isolator-free quantum dot comb lasers with optical feedback enhanced DWDM transmission

Feedback-insensitive Quantum Dot (QD) comb lasers hold significant promise for integrated dense wavelength division multiplexing photonic systems due to their ability to generate multiple wavelengths and operate without bulky isolators, facilitating the development of high-density and large-scale photonic integrated circuits. In this study, we investigated the optical feedback (OFB) influence of the InAs/GaAs QD comb laser from various perspectives. Our findings reveal that the comb laser exhibits a stable locking region with consistent optical spectra across a range of OFB strengths (−45 to −10 dB). Furthermore, under a high OFB strength of −10 dB, there is a notable 40 dB suppression of relative intensity noise in the low-frequency range (below 1 GHz). Transmission experiments demonstrate clear eye openings at 25 Gbps using a bit pattern of 231-1 pseudorandom binary sequence. Remarkably, the bit error rates decrease by five orders of magnitude under −10 dB OFB. These results indicate the ultra-robustness of 100 GHz grid QD comb laser, which exhibits great transmission enhancement under a strong OFB of −10 dB.

Complex transmission of partiti-, ambi- and ourmiaviruses in the forest pathogen Heterobasidion parviporum

Utilizing Heterobasidion partitivirus 13 strain an1 (HetPV13-an1) and 15 strain pa1 (HetPV15-pa1) in co-infection is considered a potential biocontrol approach against Heterobasidion root and butt rot. Both partitiviruses mediate debilitating effects in most Heterobasidion host isolates and are generally transmitted efficiently between host strains. In this investigation, we conducted transmission experiments in the laboratory (in vitro) using several H. parviporum isolates to test whether using dual partitivirus infections is a more efficient way of transmitting viruses to new hosts compared to using single partitivirus infections, and whether co-occurring single-stranded RNA (ssRNA) viruses are co-transmitted during the process. The results showed that H. parviporum donors carrying both partitiviruses, HetPV13-an1 and HetPV15-pa1, transmitted HetPV15-pa1 more efficiently to recipients than the same donors infected with only HetPV15-pa1. In contrast, the transmission of HetPV13-an1 did not differ significantly between donors infected with both or only one partitivirus. Altogether, the transmission rates of HetPV13-an1 and HetPV15-pa1 were high on artificial media. Moreover, the transmission of the ssRNA viruses Heterobasidion ourmia-like virus 1(HetOlV1-pa7) and 4 (HetOlV4-an1) as well as Heterobasidion ambi-like virus 3 (HetAlV3-pa4) across different recipients were found to be variable. This study demonstrated for the first time the transmission of ambi- and ourmiaviruses between H. parviporum isolates in dual cultures and showed that H. parviporum mycelia can be cured of these ssRNA viruses using heat treatment.

Modulation Format Recognition Scheme Based on Discriminant Network in Coherent Optical Communication System

In this paper, we skillfully utilize the discriminative ability of the discriminator to construct a conditional generative adversarial network, and propose a scheme that uses few symbols to achieve high accuracy recognition of modulation formats under low signal-to-noise ratio conditions in coherent optical communication. In the one thousand kilometres G.654E optical fiber transmission system, transmission experiments are conducted on the PDM-QPSK/-8PSK/-16QAM/-32QAM/-64QAM modulation format at 8G/16G/32G baud rates, and the signal-to-noise ratio parameters are traversed under experimental conditions. As a key technology in the next-generation elastic optical networks, the modulation format recognition scheme proposed in this paper achieves 100% recognition of the above five modulation formats without distinguishing signal transmission rates. The optical signal-to-noise ratio thresholds required to achieve 100% recognition accuracy are 12.4 dB, 14.3 dB, 15.4 dB, 16.2 dB, and 17.3 dB, respectively.

Increased Virulence of Culicoides Midge Cell-Derived Bluetongue Virus in IFNAR Mice.

Bluetongue (BT) is a Culicoides midge-borne hemorrhagic disease affecting cervids and ruminant livestock species, resulting in significant economic losses from animal production and trade restrictions. Experimental animal infections using the α/β interferon receptor knockout IFNAR mouse model and susceptible target species are critical for understanding viral pathogenesis, virulence, and evaluating vaccines. However, conducting experimental vector-borne transmission studies with the vector itself are logistically difficult and experimentally problematic. Therefore, experimental infections are induced by hypodermic injection with virus typically derived from baby hamster kidney (BHK) cells. Unfortunately, for many U.S. BTV serotypes, it is difficult to replicate the severity of the disease seen in natural, midge-transmitted infections by injecting BHK-derived virus into target host animals. Using the IFNAR BTV murine model, we compared the virulence of traditional BHK cell-derived BTV-17 with C. sonorensis midge (W8) cell-derived BTV-17 to determine whether using cells of the transmission vector would provide an in vitro virulence aspect of vector-transmitted virus. At both low and high doses, mice inoculated with W8-BTV-17 had an earlier onset of viremia, earlier onset and peak of clinical signs, and significantly higher mortality compared to mice inoculated with BHK-BTV-17. Our results suggest using a Culicoides W8 cell-derived inoculum may provide an in vitro vector-enhanced infection to more closely represent disease levels seen in natural midge-transmitted infections while avoiding the logistical and experimental complexity of working with live midges.

Identification of putative coral pathogens in endangered Caribbean staghorn coral using machine learning.

Coral diseases contribute to the rapid decline in coral reefs worldwide, and yet coral bacterial pathogens have proved difficult to identify because 16S rRNA gene surveys typically identify tens to hundreds of disease-associate bacteria as putative pathogens. An example is white band disease (WBD), which has killed up to 95% of the now-endangered Caribbean Acropora corals since 1979, yet the pathogen is still unknown. The 16S rRNA gene surveys have identified hundreds of WBD-associated bacterial amplicon sequencing variants (ASVs) from at least nine bacterial families with little consensus across studies. We conducted a multi-year, multi-site 16S rRNA gene sequencing comparison of 269 healthy and 143 WBD-infected Acropora cervicornis and used machine learning modelling to accurately predict disease outcomes and identify the top ASVs contributing to disease. Our ensemble ML models accurately predicted disease with greater than 97% accuracy and identified 19 disease-associated ASVs and five healthy-associated ASVs that were consistently differentially abundant across sampling periods. Using a tank-based transmission experiment, we tested whether the 19 disease-associated ASVs met the assumption of a pathogen and identified two pathogenic candidate ASVs-ASV25 Cysteiniphilum litorale and ASV8 Vibrio sp. to target for future isolation, cultivation, and confirmation of Henle-Koch's postulate via transmission assays.

Ultra-low-power consumption silicon electro-optic switch based on photonic crystal nanobeam cavity

Ultra-low-power consumption and high-speed integrated switches are highly desirable for future data centers and high-performance optical computers. In this study, we proposed an ultra-low-power consumption silicon electro-optic switch based on photonic crystal nanobeam cavities on a foundry platform. The proposed switch showed an ultra-low static-tuning power of 0.10 mW and a calculated dynamic switching power of 6.34 fJ/bit, with a compact footprint of 18 μm × 200 μm. Additionally, a 136-Gb/s four-level pulse amplitude modulation signal transmission experiment was carried out to verify the capability of the proposed electro-optic switch to support high-speed data transmission. The proposed device has the lowest static-tuning power consumption among silicon electro-optic switches and the highest data transmission rate. The results demonstrate the potential applications of this switch in high-performance optical computers, data center interconnects, optical neural networks, and programmable photonic circuits.

Quantum dot fourth-harmonic colliding pulse mode-locked laser for high-power optical comb generation

Quantum-dot mode-locked lasers have advantages such as high temperature stability, large optical bandwidth, and low power consumption, which make them ideal optical comb sources, especially for wavelength-division multiplexing (WDM) telecommunications, and optical I/O applications. In this work, we demonstrate an O-band quantum dot colliding pulse mode-locked laser (QD-CPML) to generate optical frequency combs with 200 GHz spacing with maximum channels of 12 within 3 dB optical bandwidth. To achieve the high output power of individual comb lines, four channel conditions are implemented at central wavelength of 1310 nm for WDM transmission experiments. Each channel exhibits more than 10 dBm output power with 200 Gb/s PAM-4 and 270 Gb/s PAM-8 modulation capability via thin-film LiNbO3 Mach–Zehnder interferometer modulator without the requirement of any optical amplifications. This high-order QD-CPML is an ideal comb source for power-efficient optical interconnects and large bandwidth optical data transmission.

An approximate dynamic model of double-sided LCC resonant converter in wireless power transmission based on average current model

Wireless Power Transmission (WPT) system could realize a non-contact power transmission through the air gap weak magnetic coupling. This paper aims at analyzing a dynamic model of the WPT system based on a double-side LCC. Firstly, in the multivariable framework, the dynamic characteristics of double-side LCC resonant compensation topology are analyzed by the mutual inductance model. The approximate small-signal model of double-side LCC resonant converter is derived by generalized state-space averaging (GSSA). Additionally, a double-side LCC compensation topology based on double closed-loop average current mode control approach is proposed. By contrasting the behavior of the WPT system under various operating conditions, the efficacy of the suggested dynamic model is illustrated. Finally, a wireless power transmission system experiment platform with a resonant frequency of 85 kHz and an output power of 3 kW was built. Through the experiments, it is determined that the model has a certain ability to predict the dynamic behavior of the wireless charging system. So, it can be utilized as a useful instrument for the transient's analysis and the controller development optimization.© 2017 Elsevier Inc. All rights reserved.

Predicting ultrasound wave stimulated bone growth in bioinspired scaffolds using machine learning

For conditions like osteoporosis, changes in bone pore geometry even when porosity is constant have been shown to correlate to increased fracture risk using techniques such as dual-energy x-ray absorptiometry (DXA) and computed tomography (CT). Additionally, studies have found that bone pore geometry can be characterized by ultrasound to determine fracture risk, since certain pore geometries can cause stress concentration which in turn will be a source for fracture. However, it is not yet fully understood if changes in pore geometry can be detected by ultrasound when the porosity is constant. Therefore, this study develops an unsupervised machine learning model classifying pore geometry between bioinspired and quadrilateral pore scaffolds with constant porosity using experimental ultrasound wave transmission data. Our results demonstrate that differences in pore geometry can be detected by ultrasound, even at constant porosity, and that these differences can be distinguished in an unsupervised manner with machine learning. For traumatic bone injuries and late-stage osteoporosis where fracture occurs, tissue scaffolds are used to aid the healing of fractures or bone loss. The scaffold design is optimized to match material properties closely with bone, and healing can be enhanced with ultrasound stimulation. In this study we predict the combined effects of ultrasound parameters, such as wave frequency and mode of displacement, and scaffold material properties on bone tissue growth. We therefore develop an unsupervised machine learning clustering model of bone tissue growth in the scaffolds using finite element analysis and bone growth algorithms evaluating effects of pore geometry, scaffold materials, ultrasound wave type and frequency, and mesenchymal stem cell distribution on bone tissue growth. The computational predictions of tissue growth agreed within 10% of comparable experimental studies. The data corresponding to pore geometry, mesenchymal stem cell distribution, and scaffold material demonstrate distinct clusters of total bone formation, while ultrasound frequency and mesenchymal stem cell distribution show distinct clusters in bone growth rate. These variables can be tuned to tailor the scaffold design and optimize the required amount and rate of bone growth to meet a patient's specific needs.

Concurrent performance and security enhancement of ultrahigh-order DSM signals via null subcarriers.

In this paper, we propose leveraging null subcarriers in discrete multi-tone modulation (DMT) to process the DMT signal in both time and frequency domains. Additionally, we employ discrete memory enhanced chaos (DMEC) to scramble the signal in the frequency domain, thereby achieving physical layer signal encryption while ensuring a more uniform power distribution in the time-domain waveform. In our experimental demonstration, we achieved high-security transmission of a DSM-based 65536-QAM signal at a data rate of 16.01 Gb/s over a 25 km single-mode fiber (SMF) in an intensity-modulation direct-detection (IMDD) system. Additionally, in the transmission experiments for 13684-QAM and 65536-QAM signals, the proposed method demonstrated a receiver sensitivity gain of over 0.5 dB compared to the traditional DSM-based ultrahigh-order transmission.

Low complexity and finer granularity quantization scheme for perturbation-based fiber nonlinearity compensation in coherent optical communication systems

In the efficient implementation of perturbation theory-based nonlinearity compensation method for reliable fiber-optic coherent communication systems, different quantization schemes have been proposed to reduce the required computational and implementation complexity. For example, the k-means clustering algorithm focused on reducing the number of perturbation coefficients to alleviate the burden of calculating the perturbation terms. In this paper, from the bit-level architectures of multipliers, we propose a multi-segment mixed-word-length quantization scheme that assigns different word lengths for the quantized perturbative coefficients to save computational resources, where Bayesian optimization is employed to derive the optimal hyperparameters involved in this scheme. The proposed scheme was evaluated by numerical simulations of single-channel and multi-channel optical fiber communication systems with dual-polarization 16-QAM modulation. The comprehensive numerical simulation results show that our proposed scheme demonstrates a complexity reduction of more than 65% without performance degradation compared with the traditional uniform quantization method with fixed-word-length, and was robust to the fiber length and baud-rate. We also carried out an experiment of single-carrier transmission over 18 × 100 km standard single-mode fiber with 20 Gbaud single-polarization 16-QAM signal. Similar to the numerical results, the hardware complexity can be reduced by 70.7% with negligible performance deterioration over the uniform quantization scheme. The proposed scheme shows great potential in real-world applications.

AC‐Driven Plasmon Waveguide Integrated Electroluminescent Device

AbstractPhotonic elements have greater information‐carrying capabilities compared to electronic components, making the development of high‐speed, chip‐integrated optical communication devices crucial for addressing interconnect bottlenecks in high‐speed computing systems. Significant progress has been made in studying light sources and their transmission. Despite these advancements, achieving a satisfactory integration of photonic circuits with both light source and optical waveguide functions has remained a challenge. Here, a silver nanowire (AgNW) waveguide‐integrated light source is demonstrated driven by alternating current (AC) voltage. AgNW functions as both the electrode and waveguide to simplify the device structure, and the 2D transition metal dichalcogenides (TMDs) monolayer acts as the gain media in device. The electroluminescence (EL) can be tunably modulated via adjusting the frequency and voltage of the AC in this device, and it is also successfully coupled into the waveguide with its transmission distance up to 25 µm. The experiments of electroluminescence and waveguide transmission of different materials and their interlayer excitons have made a preliminary exploration of multiple wavelength transmission. It provides a new research platform forward in the development of chip‐integrated optical communication devices, thereby hopefully addressing the interconnect bottleneck and unlocking the potential for enhanced performance and efficiency in high‐speed computing systems.

Ventilation does not affect close-range transmission of influenza virus in a ferret playpen setup

Sustained community spread of influenza viruses relies on efficient person-to-person transmission. Current experimental transmission systems do not mimic environmental conditions (e.g., air exchange rates, flow patterns), host behaviors, or exposure durations relevant to real-world settings. Therefore, results from these traditional systems may not be representative of influenza virus transmission in humans. To address this pitfall, we developed a close-range transmission setup that implements a play-based scenario and used it to investigate the impact of ventilation rates on transmission. In this setup, four immunologically naive recipient ferrets were exposed to a donor ferret infected with a genetically barcoded 2009 H1N1 virus (H1N1pdm09) for 4 h. The ferrets interacted in a shared space that included toys, similar to a childcare setting. Transmission efficiency was assessed under low and high ventilation, with air exchange rates of ~1.3 h-1 and 23 h-1, respectively. Transmission efficiencies observed in three independent replicate studies were similar between ventilation conditions. The presence of infectious virus or viral RNA on surfaces and in air throughout the exposure area was also not impacted by the ventilation rate. While high viral genetic diversity in donor ferret nasal washes was maintained during infection, recipient ferret nasal washes displayed low diversity, revealing a narrow transmission bottleneck regardless of ventilation rate. Examining the frequency and duration of ferret physical touches revealed no link between these interactions and a successful transmission event. Our findings indicate that exposures characterized by frequent, close-range interactions and the presence of fomites can overcome the benefits of increased ventilation.