Vortex Laser Based on a Plasmonic Ring Cavity

The orbital angular momentum (OAM) of the structure light is viewed as a candidate for enhancing the capacity of information processing. Microring has advantages in realizing the compact lasers required for on-chip applications. However, as the clockwise and counterclockwise whispering gallery modes (WGM) appear simultaneously, the emitted light from the normal microring does not possess net OAM. Here, we propose an OAM laser based on the standing-wave WGMs containing clockwise and counterclockwise WGM components. Due to the inhomogeneous intensity distribution of the standing-wave WGM, the single-mode lasing for the OAM light can be realized. Besides, the OAM of the emitted light can be designed on demand. The principle and properties of the proposed laser are demonstrated by numerical simulations. This work paves the way for exploring a single-mode OAM laser based on the plasmonic standing-wave WGMs at the microscale, which can be served as a basic building block for on-chip optical devices.

Parametric Study on Conventional and Pre-Engineered Multistorey Steel Building with Varying Height and Span

Technological advancement over the year has contributed immensely to the enhancement of quality of life through various new products and services. One such revolution in the field of construction industry is the pre-engineered buildings (PEB). Pre-engineered building concept involves the steel building system which are predesigned and prefabricated. Pre-engineered building structure brings optimization technique and faster construction technology. PEB are designed according to the analytical results so the section of this particular elements is tapered according to the results and this concept makes the structure light weight and also provide the best possible sections according to the optimum requirements and cost effectiveness. In current scenario pre-engineered building (PEB) construction is used for multi storey building having large span. In the present work, the study of pre-engineered building (PEB) with conventional steel building (CSB) has been carried out, in this study pre-engineered building (PEB) and conventional steel building (CSB) were designed as per IS 800:2007. Comparative assessment will be conducted between PEB system and CSB system by using STAAD Pro V8i software. I have taken different plan and different material specifications also different height (G+10, G+20) and different span (3880 mm, 4850 mm) for plans for study of material consumption. After the study result of PEB and CSB structures observed that the PEB structures reduce the material consumption.

A Framework in Calibration Process for Line Structured Light System Using Image Analysis

Line structured light systems have been widely applied in the measurement of various fields. Calibration has been a hot research topic as a vitally important process of the line structured light system. The accurate calibration directly affects the measurement result of the line structured light system. However, the external environment factors, such as uneven illumination and uncertain light stripe width, can easily lead to an inaccurate extraction of light stripe center, which will affect the accuracy of the calibration. An image analysis-based framework in the calibration process was proposed for the line structure light system in this paper. A three-dimensional (3D) vision model of line structure light system was constructed. An image filtering model was established to equalize the uneven illumination of light stripe image. After segmenting the stripe image, an adaptive window was developed, and the width of the light stripe was estimated by sliding the window over the light stripe image. The light stripe center was calculated using the gray centroid method. The light plane was fitted based on the calibration points coordinates acquired by the camera system. In the measurement experiment of standard gauge block width, the maximum and minimum average deviations of 0.021 pixels and 0.008 pixels and the maximum and minimum absolute deviations of 0.023 pixels and 0.009 pixels could be obtained by using the proposed method, which implies the accuracy of the proposed method.

Enhancement of redox capacity derived from O-doping g-C3N4/WO3 nanosheet for photocatalytic degradation of tetracycline under different dissolved oxygen concentration

Element-doping is an essential method to adjust band structure, light absorbance and charge transfer and separation of semiconductor. Besides, whether the photocatalyst could work in oxygen-deficient environment is also important....