A New Architecture for Nonblocking Optical Switching Networks

In this paper, we present a new photonic switching network. The proposed network is constructed by concatenating modified plus-minus 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">i</sup> and inverse modified plus-minus 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">i</sup> networks with two center stage overlapped. The performance is evaluated and compared with other networks to show the superiority of the proposed network over other networks. To construct the proposed network we require less number of switching elements. The proposed network yields less signal loss and first-order crosstalk, thus it scales well. The proposed network is a good choice for constructing photonic switch with low signal loss and cross talk.

In equine surface electromyography (sEMG), challenges related to the reliability and interpretability of data arise, among other factors, from methodological differences, including signal processing and analysis. The aim of this study is to demonstrate the filtering-induced changes in basic signal features in relation to the balance between signal loss and noise attenuation. Raw sEMG signals were collected from the quadriceps muscle of six horses during walk, trot, and canter and then filtered using eight filtering methods with varying cut-off frequencies (low-pass at 10 Hz, high-pass at 20 Hz and 40 Hz, and bandpass at 20-450 Hz, 40-450 Hz, 7-200 Hz, 15-500 Hz, and 30-500 Hz). For each signal variation, signal features-such as amplitude, root mean square (RMS), integrated electromyography (iEMG), median frequency (MF), and signal-to-noise ratio (SNR)-along with signal loss metrics and power spectral density (PSD), were calculated. High-pass filtering at 40 Hz and bandpass filtering at 40-450 Hz introduced significant filtering-induced changes in signal features while providing full attenuation of low-frequency noise contamination, with no observed differences in signal loss between these two methods. Other filtering methods led to only partial attenuation of low-frequency noise, resulting in lower signal loss and less consistent changes across gaits in signal features. Therefore, filtering-induced changes should be carefully considered when comparing signal features from studies using different filtering approaches. These findings may support cross-referencing in equine sEMG research related to training, rehabilitation programs, and the diagnosis of musculoskeletal diseases, and emphasize the importance of applying standardized filtering methods, particularly with a high-pass cut-off frequency set at 40 Hz.

Silver nanowires are printable and conductive, and are believed to be promising materials in the field of printed electronics. However, the resistivity of silver nanowire printed lines is higher than that of metallic particles or flakes even when sintered at high temperatures of 100-400 °C. Therefore, their applications have been limited to the replacement of transparent electrodes made from high-resistivity materials, such as doped metallic oxides, conductive polymers, carbon nanotubes, or graphenes. Here we report that using printed silver nanowire lines, signal losses obtained in the high-frequency radio were lower than those obtained using etched copper foil antennas, because their surfaces were much smoother than those of etched copper foil antennas. This was the case even though the resistivity of silver nanowire lines was 43-71 μΩ cm, which is much higher than that of etched copper foil (2 μΩ cm). When printed silver nanowire antennas were heated at 100 °C, they achieved signal losses that were much lower than those of silver paste antennas comprising microparticles, nanoparticles, and flakes. Furthermore, using a low temperature process, we succeeded in remotely controlling a commercialized radio-controlled car by transmitting a 2.45 GHz signal via a silver nanowire antenna printed on a polyethylene terephthalate film.

This work demonstrates the development of surface treatment systems of copper which can meet all of the challenges of mobile electronic devices manufacturing for high frequency function. These challenges are low signal loss and enhanced functional performances. The developed surface treatment systems adopted subsequent treatment of organic coating and organosilane coating so called “adhesion promotor” on top of copper surface to provide the strongest possible bond strength. Firstly, this work has been focused upon the relationship between Signal Integrity (SI) data and Surface Roughness Data. The investigation at high frequency region shows the greatest correlation between relative surface area increase (RSAI) and measured signal loss. The loss of measured signal integrity is linearly increased as a function of RSAI increase, due to more augmented effect of the skin effect at high frequency. As the basis for low roughness oxide replacement process (OR HF#1, OR HF1 VS and OR HF#2), modification was done by adjusting different components in the etching solution. Significantly improved signal integrity are shown for all processes. At the same time, adhesion promotor (organic or oganosilane coating) is successfully enhanced adhesion performance and thermal reliability. Adhesion promotor compensating the loss of adhesion performance due to reduced mechanical anchoring of low roughness surface. Further move to the future high frequency electronics manufacturing, advanced adhesion promotor process is developed as alternative. Contrary to oxide replacement, this process is based on ferric sulfate chemistry in etching solution. Combination of low roughness and chemical bond from organosilane coating implies the process as the best fit to high frequency electronics manufacturing, where low insertion loss is required.

Traditional radar signal classification struggles in complex electromagnetic environments due to reliance on single features and insufficient temporal modeling. This paper introduces a robust classification framework combining intra-pulse multi-feature fusion with a TCN-GCN hybrid architecture to address these issues. Specifically, we employ a gated attention mechanism to integrate time-frequency, phase, and bispectrum features, while the TCN-GCN model captures complex temporal characteristics and inter-signal dependencies. Empirical results show the proposed method outperforms existing techniques, delivering high classification accuracy and strong resilience against low SNR, pulse overlap, and signal loss.

As data centers enter the exascale computing era, the traffic exchanged between internal network nodes, increases exponentially. Optical networking is an attractive solution to deliver the high capacity, low latency, and scalable interconnection needed. Among other switching methods, packet switching is particularly interesting as it can be widely deployed in the network to handle rapidly-changing traffic of arbitrary size. Nanosecond-reconfigurable photonic integrated switch fabrics, built as multi-stage architectures such as the Clos network, are key enablers to scalable packet switching. However, the accompanying control plane needs to also operate on packet timescales. Designing a central scheduler, to control an optical packet switch in nanoseconds, presents a challenge especially as the switch size increases. To this end, we present a highly-parallel, modular scheduler design for Clos switches along with a proposed routing scheme to enable nanosecond scalable scheduling. We synthesize our scheduler as an application-specific integrated circuit (ASIC) and demonstrate scaling to a 256 × 256 size with an ultra-low scheduling delay of only 6.0 ns. In a cycle-accurate rack-scale network emulation, for this switch size, we show a minimum end-to-end latency of 30.8 ns and maintain nanosecond average latency up to 80% of input traffic load. We achieve zero packet loss and short-tailed packet latency distributions for all traffic loads and switch sizes. Our work is compared to state-of-the-art optical switches, in terms of scheduling delay, packet latency, and switch throughput.

Guest editorial “Ephemeralization” is the term coined by engineer Buckminster Fuller, the father of the geodesic dome and an early environmental activist, to describe the advancement of technology that achieves “more and more with less and less until eventually you can do everything with nothing.” This idea of doing more with less is at the heart of advances in downhole fiber-optic technology, and, in relative terms, its application is not far removed from doing nearly everything with almost nothing. Using light-transmitting optical fibers slightly thicker than a human hair and similar to the technology that brings Internet capacity to your home, we have been measuring wellbore parameters such as temperature, pressure, strain, vibration, and sound (acoustics) for years. In the near future, with the development of new optical or photonic sensing methods for chemical, microdeformation, resistivity, magnetic field, and other monitoring solutions, the industry will be able to integrate, visualize, and analyze numerous operations and activities downhole in real time, thus extending the life of the well and the reservoir. More Photons, Fewer Electrons Fuller illustrated his concept of ephemeralization by comparing the tons of copper wire required for a trans-Atlantic communication cable that could be replaced with ounces of the copper wire that it takes for a single communications satellite. With fiber-optic cables, the comparison is equally dramatic in many ways. Legacy electronic systems require deployment of complex, dedicated downhole instruments with millions of transistor junctions to make discrete wellbore measurements at specific points and times. In marked contrast, fiber-optic technology uses low-cost, low signal loss, high-bandwidth, silica glass transmission lines down-hole in concert with surface optoelectronic instruments to continually acquire real-time, remote, fully distributed measurements over the entire length of the installation, making the solution highly scalable. Leaving instrumentation on the rig floor, and not within the wellbore, removes risk from the hostile environment and enhances operating parameters. For instance, fiber-optic sensing and monitoring have been used in environments of up to 300°C (572°F) for years with great success. Solutions exist today for much higher temperatures. In contrast, electronic solutions are limited to less than about 200°C (392°F) for permanent deployment. As the technology evolves, surface instrumentation can be upgraded and connected to the same downhole fiber-optic sensors, instantly providing better data and potentially new sensing applications. For example, instrumentation connected to fiber-optic cables originally deployed on pipelines for telemetry decades ago is now being used to monitor distributed flow, temperature, acoustics, and tubular strain across many kilometers, thus enabling leak detection, flow restriction identification, object tracking, and other capabilities.

A new concept for an on-chip millimeter-wave dielectric resonator antenna is presented. A spherical dielectric resonator is placed on the chip surface and is excited by an on-chip microstrip feed. A shallow crate is etched in the polymer layers atop the bulk semiconductor, in close proximity of the microstrip feed. The dielectric sphere placed into the crate will position itself to high precision. The microstrip feed structure forms a parallel resonant circuit from line to ground. Before mounting the sphere, the feed point can be on-wafer tested with conventional 50 Ohm ground-signal-ground probes. Measurements at 69 GHz are presented. The concept combines mechanical simplicity and low signal loss.

In this paper we consider the routing and wavelength assignment problem in a wavelength routed all optical network. Inspired by techniques from artificial intelligence, in particular the Blocking Island (BI) abstraction, we propose a simple and intelligent routing and wavelength assignment (RWA) algorithm: BI_RWA. This algorithm can be used in arbitrarily connected optical networks. In addition, it is general enough such that with some simple modifications, it can be applied to different optical networking scenarios: static or dynamic traffic, single or multiple fiber links between node pairs, with or without wavelength converters. We have conducted simulation experiments to evaluate the performance of our algorithm. The simulation is carried out in two parts: static traffic and dynamic traffic. The results will demonstrate that our RWA algorithm outperforms state-of-the-art related algorithms.

Randomized self-routing algorithms for Clos networks

As power grids and optical interconnection networks are interdependent, the reliabilities of the optical networks are critical issues in power systems. The optical networks hold prominent performance including wide bandwidth, low loss, strong anti‐interference capability, high fidelity, and reliable performance. They are regarded as promising alternatives to electrical networks for parallel processing. This paper is aimed at taking the first step in understanding the communication efficiencies of optical networks. For that purpose, on optical networks, we propose a series of novel notions including communication pattern, r‐communication graph, reduced diameter, enhanced connectivity, r‐diameter, and r‐connectivity. Using these notions, we determine that the r‐diameter and r‐connectivity of the optical n‐dimensional hypercube network are ⌈n/r⌉ and , respectively. Since the parameter r is variable, we can adjust different values of r on the basis of the wavelength resources and load of the optical networks, achieving enhanced communication efficiencies of these networks. Compared with the electric n‐dimensional hypercube network, the proposed communication pattern on the optical hypercube network not only reduces the maximum communication delay of the conventional electrical hypercube significantly but also improves its fault tolerance remarkably.

Optical networks are the backbone of today’s high-speed communication systems, but they can be attacked in many ways. Hackers might use advanced methods like wormhole attacks, Sybil attacks, or single-point failures to disrupt or take control of the network. Most current security systems rely on complex math to protect data. But with the development of quantum computers, those systems are no longer fully safe. Quantum computers could break these protections easily in the future. This problem can be solved by integrating two powerful technologies: Quantum Key Distribution (QKD) and blockchain This combination is called quantum-secured blockchain. This system removes the need for older, potentially breakable digital signatures, and instead uses methods that are resistant to quantum computer attacks. They also rely on new quantum materials and nanomaterials, which help in making better light sources, reducing signal loss and storing quantum information more reliably. AI and machine learning are now being used to speed up the discovery of these advanced materials such as superconductors, quantum dots and special optical fibers that are required to make the technology practical and scalable. This paper explains the different types of attacks that can occur in optical networks and the ways to protect optical networks using quantum-secured blockchain along. It gives the introduction to blockchain technology along with its security weaknesses, and then focuses on Quantum Key Distribution (QKD), which can make blockchain much stronger against attacks from powerful quantum computers. It also provides an overview of how quantum-secured blockchain works to secure optical communication networks.

In this paper, we present a new wide-sense nonblocking optical switching network. The proposed network combines some building blocks, which is All-To-All Personalized Exchange Multistage Interconnection Network. The architectural details and some other parameters are evaluated and compared with other networks to show the superiority of the proposed network over other networks. To construct the proposed network we require less number of switching elements. In addition, it provides constant first order crosstalk, thus it scales well. The proposed network is a good choice for constructing nonblocking optical switch with less switching element and signal loss.

A novel, to the best of our knowledge, Rayleigh-Brillouin scattering (RBS) spectrometer based on a virtually imaged phased array (VIPA) with a high spectral resolution is proposed for rapid gas temperature detection. CO2 RBS spectra at gas pressure of 0.5-4 bar were acquired with a spectrum acquisition time of 10 s, and temperature inversion analysis was performed using TENTI S6 model. The root-mean-square error (RMSE) of the RBS profile fitting is less than 2.95%, and the maximum absolute error of temperature inversion is less than 2.45 K. Compared with traditional methods, this method has low RBS signal loss and short acquisition time without the frequency scanning process, which is more conducive to real-time detection applications.

POSITRON emission tomography (PET) is used in assessing therapy response, staging, and restaging of breast cancer [1]. However, whole-body PET scanners are not ideally suited to breast imaging due to low geometric sensitivity, low spatial resolution and signal loss due to attenuation in the body. Several groups are working on dedicated breast imaging systems to overcome such limitations[2][3]. Due to the typically smaller field of view (FOV), detectors capable of measuring depth of interaction (DOI) can yield better performance in dedicated breast PET scanners. A high resolution positron emission tomography/computed tomography (PET/CT) scanner that uses DOI encoding detectors and is dedicated for human breast imaging is currently been developed in our laboratory. This paper presents the design and implementation of a prototype of the PET component of the aforementioned scanner.