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The tunable perfect magnetic mirror effect and the retroreflector property may provide ways in novel photonic devices and sensing applications.Programmable multipurpose photonic integrated circuits require software routines to make use of their flexible operation as desired. In this work, we propose and demonstrate the use of a modified tree-search algorithm to automatically determine the optimum optical path in a field-programmable photonic gate array (FPPGA), based on end-user specifications, circuit architecture and imperfections in the realized FPPGA arising, for example, from fabrication variations. In such a scenario, the proposed algorithm only requires the hardware topology and the location of the connections of the FPPGA defining the optical path to be programmed. The routine is able to optimize the path over multiple and competing objectives like the overall length, accumulated loss and power consumption. In addition, should any region of the circuit suffer from any potential damage that may affect the device performance, this algorithm is also able to provide basic self-healing and fault-tolerance capabilities by supplying alternative paths through the photonic arrangement.This paper presented a heterodyne speckle interferometer (HSI) for the measurement of two-dimensional in-plane displacement. A diffraction grating is used to split the light source into four beams, which are then reflected into a non-mirror measurement surface at symmetrical incident angles, before being scattered to form an interference pattern. In accordance with the Doppler Effect, in-plane displacement of the surface causes phase variations in speckle interference patterns, from which displacement information can be obtained. Several experiments were performed to evaluate the feasibility of the proposed HSI. Experiment results demonstrate that the proposed system is capable of accurately measuring in-plane displacement with a resolution of approximately 1.5 nm.Two diffractive optical elements are used to create a compact raster THz scanning setup in reflective configuration. The first one focuses the radiation into the small focal spot on the sample, while the second one collects reflected radiation and focuses it on the detector. To assure small size of the setup and large apertures of optical elements, structures work in the off-axis geometry. Thus, the focal spot is formed 100 mm after and 60 mm below the optical axis of the element, which measures 75 mm in diameter. The designed iterative algorithm allows further minimization of these values.Photonic topological transitions (PTTs) in metamaterials open up a novel approach to design a variety of high-performance optical devices and provide a flexible platform for manipulating light-matter interactions at nanoscale. Here, we present a wideband spectral-selective solar absorber based on multilayered hyperbolic metamaterial (HMM). Absorptivity of higher than 90% at normal incidence is supported over a wide wavelength range from 300 to 2215 nm, due to the topological change in the isofrequency surface (IFS). The operating bandwidth can be flexibly tailored by adjusting the thicknesses of the metal and dielectric layers. Moreover, the near-ideal absorption performance can be retained well at a wide angular range regardless of the incident light polarization. These features make the proposed design hold great promise for practical applications in energy harvesting.In this paper, we introduce a novel method for the fabrication of self-assembly plasmonic metamaterials by exploiting fluid instabilities of optical thin films. Due to interplay between template reflow and spinodal dewetting, two metal nanoparticles of different sizes are generated on the top mesas of free-standing porous anodic aluminum oxide (AAO) template, which results in the apprearance of double resonant peaks in the extinction spectrum. These two resonant peaks possess refractive index resolution 3.27?×?10-4 and 2.53?×?10-4 RIU, respectively. This optical intensity modulation based plasmonic nanoplatform shows a dramatically surface sensing performance with outstanding detection capacity of biomolecules, because of the very small decay length of electric field at dual-modes. https://www.selleckchem.com/products/otub2-in-1.html The detection ability for concanavalin A (Con A) demonstrats that the limit of detection of dual-modes reaches as small as 68 and 79 nM, respectively.A novel approach for the production of both amorphous and crystalline selenium nanoparticles (SeNPs) using femtosecond laser-induced plasma shock wave on the surface of Bi2Se3 topological insulators at room temperature and ambient pressure is demonstrated. The shape and size of SeNPs can be reliably controlled via the kinetic energy obtained from laser pulses, so these are applicable as active components in nanoscale applications. Importantly, the rapid, low-cost and eco-friendly synthesis strategy developed in this study could also be extendable to other systems.A novel combined laser pulses (CLPs) consisting of a millisecond (ms) pulse and an assisted nanosecond (ns) pulse train was proposed for drilling alumina ceramic. The processing efficiency and quality were well improved by spatially and temporally superposing the ms and ns laser beams. As a result, due to the multi-reflection of keyhole and ejection of melt, the temporally superposed CLPs could decrease the energy consumption of the drilling by an order of magnitude compared with the conventional ms pulse. On the other hand, the spatial distribution of the ns laser on the focal plane was elliptical due to the off-axis distortion of the optical system. However, since the reflection of the laser in the keyhole was non-uniform, the spatially superposed CLPs showed no dependence on the shape of the focused elliptical ns laser spot in terms of the drilling quality. The research results have an important guiding for improving the efficiency and quality of laser processing, especially for the alumina ceramic laser processing.We investigated the effect of coupled quantum wells to reduce electron overflow in InGaN/GaN dot-in-a-wire phosphor-free white color light-emitting diodes (white LEDs) and to improve the device performance. The light output power and external quantum efficiency (EQE) of the white LEDs with coupled quantum wells were increased and indicated that the efficiency droop was reduced. The improved output power and EQE of LEDs with the coupled quantum wells were attributed to the significant reduction of electron overflow primarily responsible for efficiency degradation through the near-surface GaN region. Compared to the commonly used AlGaN electron blocking layer between the device active region and p-GaN, the incorporation of a suitable InGaN quantum well between the n-GaN and the active region does not adversely affect the hole injection process. Moreover, the electron transport to the device active region can be further controlled by optimizing the thickness and bandgap energy of this InGaN quantum well. In addition, a blue-emitting InGaN quantum well is incorporated between the quantum dot active region and the p-GaN, wherein electrons escaping from the device active region can recombine with holes and contribute to white-light emission.
