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.

Phase noise-induced interference for coherently detected OTDR systems.

The phase noise-induced interference (PNII) in coherently detected OTDR systems is investigated. A close-form relationship between signal to (interference) noise ratio (SNR) and laser linewidth is derived for the first time, to the best of our knowledge, and numerical simulations are conducted to verify the theoretical results. Additionally, the proportion of noise composition of PNII is studied.

Robust speckle-free imaging using random lasers enhanced by TiN nanoparticles in complex scattering environments.

A light source with narrowband, sufficient brightness, and low spatial coherence is required for certain applications such as optical imaging and free-space optical communication. In this study, our focus was to investigate a novel imaging laser source, specifically a low-threshold random laser enhanced by TiN nanoparticles. The results demonstrate that the random laser spectrum exhibits an impressive bandwidth of 0.

Efficient dynamic tunable metasurface based on GeSbTe in the near infrared band.

For effective wavefront management in the optical infrared range, dynamic all-dielectric metasurfaces, always based on phase transition materials, particularly (GST), can be used. In this paper, we propose a GST-based tunable metasurface by structuring the phase-change material GST. We confirm that the nanopillar we designed has high transmittance in the wavelength band around 1550 nm and can fully cover the 0∼2 phase.

Adjustable converter of bound state in the continuum basing on metal-graphene hybrid metasurfaces.

The bound state in the continuum (BIC) is widely applied to metamaterial study in order to obtain robust resonance and high quality (Q) factor. In this paper, we propose a metallic metasurface structure that can support double types of BICs, and acquire quasi-BIC state by restructuring each type with a specific approach. Electric field distribution is investigated to explore the physic mechanism behind the evolution of BICs.

Sports Injury Identification Method Based on Machine Learning Model.

With the increasingly fierce competition in international competitive sports, the momentum of special training has increased. Sports injuries are becoming more and more serious, which restricts the further improvement of the level of athletes. How to solve the problem of prevention, treatment, and rehabilitation of sports injuries, so as to ensure the normal training and competition of athletes, is an important part of sports work.

Applying deep learning-based regional feature recognition from macro-scale image to assist energy saving and emission reduction in industrial energy systems.

Introduction: Image recognition technology has immense potential to be applied in industrial energy systems for energy conservation. However, the low recognition accuracy and generalization ability under actual operation conditions limit its commercial application.

Objectives: To improve the recognition accuracy and generalization ability, a novel image recognition method integrating deep learning and domain knowledge was applied to assist energy saving and emission reduction for industrial energy systems.

Multibit NOT logic gate enabled by a function programmable optical waveguide.

Multibit logic gates are of great importance in optical switching and photonic computing. A 4-bit parallel optical NOT logic gate is demonstrated by an optical switching/computing engine based on a multimode waveguide. The multimode interference (MMI) patterns can be altered by thermal electrodes because the number of guided modes, their profiles, and propagation constants can all be altered via the thermo-optic effect.

Material contact sensor with 3D coupled waveguides.

An evanescent field sensor to identify materials by contact has been demonstrated using a 3D coupled waveguide array. The array is formed by imbedding layered silicon nitride stripes as waveguide cores in polymer cladding and the top cladding layer is etched open for material sensing. When objects with different refractive indexes are placed on the surface of the sensor, the evanescent field is disturbed and both the local modal distribution and the coupling condition with the connecting segments are altered, leading to different interference patterns when light from the output facet is captured and focused onto a camera.

Multiport all-logic optical switch based on thermally altered light paths in a multimode waveguide.

A generic multiport optical switch capable of generating all-logic outputs is demonstrated by altering the mode profiles and propagation characteristics in a multimode waveguide through a combination of microheaters. The principles and design rules are introduced. As proof of concept, a 3-bit all-logic switch is fabricated on a polymer waveguide platform.

3D integrated wavelength demultiplexer based on a square-core fiber and dual-layer arrayed waveguide gratings.

We present a 3D integrated wavelength demultiplexer using a square-core fiber (SCF) and matched dual-layer arrayed waveguide gratings (AWGs). The SCF works as a 3D fiber multimode interference device, which splits the input light into symmetric four spots. The spots are then coupled to a pitch-matched 4-waveguide network, each connecting an AWG.

Thermal stability of optical fiber metal organic framework based on graphene oxide and nickel and its hydrogen adsorption application.

The electrochemistry (EC) method was used to synthesize graphene oxide-nickel (GO-Ni) metal organic framework (MOF) that has the thickness of μm-level. The MOF's thermal stability and hydrogen adsorption and desorption capacity were measured by using an optical fiber Mach-Zehnder interferometer (MZI) sensor. This MZI was fabricated by core-offset fusion splicing one section of single mode fiber (SMF) between two SMFs.

An unexpected INAD PDZ tandem-mediated plcβ binding in photo receptors.

INAD assembles key enzymes of the compound eye photo-transduction pathway into a supramolecular complex, supporting efficient and fast light signaling. However, the molecular mechanism that governs the interaction between INAD and NORPA (phospholipase Cβ, PLCβ), a key step for the fast kinetics of the light signaling, is not known. Here, we show that the NORPA C-terminal coiled-coil domain and PDZ-binding motif (CC-PBM) synergistically bind to INAD PDZ45 tandem with an unexpected mode and unprecedented high affinity.

A Novel Fiber Optic Surface Plasmon Resonance Biosensors with Special Boronic Acid Derivative to Detect Glycoprotein.

We proposed and demonstrated a novel tilted fiber Bragg grating (TFBG)-based surface plasmon resonance (SPR) label-free biosensor via a special boronic acid derivative to detect glycoprotein with high sensitivity and selectivity. TFBG, as an effective sensing element for optical sensing in near-infrared wavelengths, possess the unique capability of easily exciting the SPR effect on fiber surface which coated with a nano-scale metal layer. SPR properties can be accurately detected by measuring the variation of transmitted spectra at optical communication wavelengths.

A Novel Low-Power-Consumption All-Fiber-Optic Anemometer with Simple System Design.

A compact and low-power consuming fiber-optic anemometer based on single-walled carbon nanotubes (SWCNTs) coated tilted fiber Bragg grating (TFBG) is presented. TFBG as a near infrared in-fiber sensing element is able to excite a number of cladding modes and radiation modes in the fiber and effectively couple light in the core to interact with the fiber surrounding mediums. It is an ideal in-fiber device used in a fiber hot-wire anemometer (HWA) as both coupling and sensing elements to simplify the sensing head structure.

Biochemical and structural characterization of MUPP1-PDZ4 domain from Mus musculus.

Specific protein-protein interactions are important for biological signal transduction. The postsynaptic density-95, disc-large, and zonulin-1 (PDZ) domain is one of the most abundant protein interaction modules. Multi-PDZ-domain protein 1 (MUPP1), as a scaffold protein, contains 13 PDZ domains and plays an important role in cytoskeletal organization, cell polarity, and cell proliferation.

Self-renewal and differentiation of muscle satellite cells are regulated by the Fas-associated death domain.

Making the decision between self-renewal and differentiation of adult stem cells is critical for tissue repair and homeostasis. Here we show that the apoptotic adaptor Fas-associated death domain (FADD) regulates the fate decisions of muscle satellite cells (SCs). FADD phosphorylation was specifically induced in cycling SCs, which was high in metaphase and declined in later anaphase.

A critical role of Fas-associated protein with death domain phosphorylation in intracellular reactive oxygen species homeostasis and aging.

Aim: Reactive oxygen species (ROS) plays important roles in aging. However, the specific mechanisms for intracellular ROS accumulation, especially during aging, remain elusive.

Results: We have reported that Fas-associated protein with death domain (FADD) phosphorylation abolishes the recruitment of phosphatase type 2A C subunit (PP2Ac) to protein kinase C (PKC)βII, which specifically regulates mitochondrial ROS generation by p66shc.