Optical splitters and combiners which can provide precise splitting with low loss, high thermal stability, large optical bandwidth, compactness, insensitivity to fabrication tolerances are essential components for performance Mach-Zehnder Interferometers (MZI)-based modulators. In this letter, we theoretically experimentally investigate the multimode interference (MMI) based structure reduction in loss achievable through use of linear tapers at input output ports. Our data shows that losses...

Due to its excellent electronic and photonic properties, silicon is a good candidate for mid-infrared optoelectronic devices systems that can be used in host of applications.In this paper we review some the results reported recently, also present several new on midinfrared including Mach-Zehnder interferometers, multimode interference splitters multiplexers based silicon-oninsulator, polysilicon, suspended silicon, slot waveguide platforms.

Bearing incipient fault diagnosis is very crucial to the timely condition-based maintenance (CBM), but it also relatively difficult because of faint feature and environmental interference. In this article, an adaptive optimized time-varying filtering-based empirical mode decomposition (TVF-EMD) (AO-TVF-EMD) put forward extract more explicit abundant features by optimizing parameter combination in conventional TVF-EMD. First, a novel integrated indicator termed sparsity-impact measure index...

We proposed and experimentally demonstrated wavelength division (de)multiplexers (WDMs) utilizing the dispersive nature of self-imaging multimode interferometers. Proof-of-principle devices fabricated on silicon-on-insulator platform operated as 4-channel WDMs with a free spectral range >90 nm, an averaging cross talk <−20 dB for 1 nm band, insertion loss <2.0 dB. The potential higher channel counts smaller spacing was also predicted. This type WDM is easy to design fabricate. underlying...

Strain engineering of patterned silicon on a sapphire wafer is achieved by modulating the spatial confined plasma during ultrafast laser-induced backward transfer. High-energy laser-ablated can be generated within space, where transitional SiOx layer formed in silicon-sapphire interface. Heat transfer to thus hindered, which beneficial for thermal accumulation and crystallinity improvement. Meanwhile, tensile strain induced deposited coordinate lattice mismatch at heterojunction difference...

We report modulation of the absorption coefficient at 1.3 μm in Ge/SiGe multiple quantum well heterostructures on silicon via quantum-confined Stark effect. Strain engineering was exploited to increase direct optical bandgap Ge wells. grew 9 nm-thick wells a relaxed Si0.22Ge0.78 buffer and contrast factor greater than 3.2 achieved spectral range 1290–1315 nm.

As a powerful time-frequency signal analysis technique, empirical mode decomposition (EMD) has been commonly applied in fault diagnosis. However, the cubic spline-curve often causes outstanding over and undershoot problem, which significantly limits performance of conventional EMD. To address this an improved EMD (I-EMD) based on adaptive weighted rational quartic spline is proposed. Firstly, original interpolation replaced with (WRQSI) two adjustable shape control parameters. Secondly,...

Abstract Empirical mode decomposition (EMD) can decompose complex non-stationary signals into the sum of several intrinsic functions (IMF), and it is widely used in fault diagnosis mechanical devices. In order to solve mixing problem enhance feature extraction ability, an adjustable envelope based EMD (AE-EMD) method was proposed. Firstly, fitting replaced by rational Hermite interpolation, which effectively avoid outstanding over undershoot conventional curve. Secondly, optimal parameter...

Integration of wafer-scale oxide and semiconductor materials meets the difficulties residual stress incompatibility. In this work, Ag NPs thin film is contributed as an energy confinement layer between (Sapphire) (Si) wafers to localize interaction during ultrafast laser irradiation. Due plasmonic effects generated within constructed dielectric-metal-dielectric structures (i.e., Sapphire-Ag-Si), thermal diffusion chemical reaction its neighboring facilitate microwelding Sapphire Si wafers....

We have demonstrated a coarse wavelength (de)multiplexing structure on the silicon-on-insulator platform. It comprises two 4-channel angled multimode interferometers interleaved with an imbalanced Mach-Zehnder interferometer (MZI) leading to 8-channel multiplexing device. The device requires only single lithography and etching steps for fabrication has good tolerance errors in terms of waveguide width. insertion loss crosstalk achieved are 3-4 dB –(15–20) dB, respectively. Potential is shown...

A method based on singular value decomposition (SVD) and fuzzy neural network (FNN) was proposed to extract diagnose the fault features of diesel engine crankshaft bearings efficiently accurately. Firstly, vibration signals in known state under same working condition were decomposed by EMD obtain modal components containing fault‐feature information. Then, values which include main used as initial vector matrix, where eigenvectors form a characteristic matrix. At last, matrix trained...

Aiming at the problems of poor self-adaptive ability in traditional feature extraction methods and weak generalization single classifier under big data, an internal parameter-optimized Deep Belief Network (DBN) method based on grasshopper optimization algorithm (GOA) is proposed. First, minimum Root Mean Square Error (RMSE) network training taken as fitness function, which GOA used to search for optimal parameter combination DBN. After that learning rate number batch DBN have great influence...

A low-cost and high-performance wavelength division (de)multiplexing structure in the mid-IR range is demonstrated on silicon-on-insulator platform using an interleaved angled multimode interferometer (AMMI). As compared to a single AMMI, channel count was doubled spacing halved with negligible extra insertion loss crosstalk only slight increase device footprint. The requires lithography etching steps for fabrication. Potential also shown achieving improved performance further optimized design.

Abstract Strong metal‐support interaction (SMSI) has drawn much attention in heterogeneous catalysts due to its stable and excellent catalytic efficiency. However, construction of high‐performance oxide‐capsulated metal nanostructures meets great challenge materials thermodynamic compatibility. In this work, dynamically controlled formation nanoparticles (NPs) structures is demonstrated by ultrafast laser plasmonic nanowelding. Under the strong localized electromagnetic field interaction,...

The development of low-thermal-budget Ge-on-Si epitaxial growth for the fabrication low-cost devices is highly desirable field silicon photonics. At present, most techniques require high temperatures, followed by cyclic annealing at temperatures > 800°C, often a period several hours. Here, we present low-temperature (400°C) plasma-enhanced chemical vapor deposition (PECVD) study and, subsequently, fabricate high-speed zero-bias 12.5-Gb/s waveguide integrated photodetector with responsivity...

Ultralong graphene nanoribbons (GNRs) have drawn much attention in the field of high performance nanoelectronics. In this work, a mask-free ultrafast laser lithography method is demonstrated for mass production ultralong GNR arrays with an intact carbon network. The longest reaches ∼42 μm width ∼400 nm. orientation as-received always parallel to incident polarization direction. Original network structures remaining GNRs are preserved, which ascribed precise energy injection and selective...

Laser sintering of metal nanoparticles (NPs) has been widely used in flexible microelectronic device fabrication, wherein the sintered layer thickness is a key factor affecting mechanical stability and conductivity. In this work, ultrathin electronic circuits on substrates with robust bonds excellent conductivity have fabricated through ultrafast laser-induced thickness-limited NP film. When laser fluence below damage threshold film, can be controlled by parameters. The maximum dense limited...

Bearing performance degradation assessment has great significance to condition‐based maintenance (CBM). A novel modeling method based on EMD‐SVD and fuzzy neural network (FNN) was proposed identify evaluate the process of bearings in whole life cycle accurately. Firstly, vibration signals known states were decomposed by empirical mode decomposition (EMD) obtain intrinsic functions (IMFs) containing feature information. Then, selected key IMFs which contain main features singular value (SVD)....

Aircraft survivability assessment is one of the most important steps aircraft project. Many models were developed to assess one-on-one engagement survivability; however, them belong in simulation category. Based on theory stochastic duel, this paper constructs an analytic model for engagement-level assessment. The explicitly represents encounter process between and weapon system, such as target detection, acquisition firing, reloading firing. general solution survival probability obtained...