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We configure an explainable machine learning-enabled just-enough margin for each lightpath in dynamic S+C+L-band optical networks. Explainable decisions improve blocking ratio and spectral efficiency performances by 35.9% and 17.2% compared with the benchmarks.

We propose and numerically analyze a broadband and high extinction ratio mode converter to achieve the mode conversion between the fundamental transverse electric mode (TE0) and the first-order transverse magnetic mode (TM1). The mode converter is achieved by using the tapered hybrid plasmonic waveguide which the metal is directly covered on the Si waveguide without a thin low-index layer. After optimizing the structure of the tapered hybrid plasmonic waveguide, a wide operation bandwidth of 100 nm is obtained with the extinction ratio of the TM1 mode and TE0 mode larger than 20 dB in the output Si waveguide for the forward propagation. And for the back propagation, the operation bandwidth over 65 nm is obtained with the extinction ratio larger than 20 dB in the output Si waveguide. The whole footprint of the mode converter is only 0.8 × 11 μm2. Fabrication tolerance analysis is also demonstrated.

A polarization beam splitter is proposed using silicon-nitride-assisted three-waveguide couplers. With 7 μm coupling length, the extinction ratios are more than 30 dB and insertion losses are less than 0.15 dB at 1.55 μm wavelength.

The GaAsP/Si dual-junction solar cells have been systematically investigated in our paper by using AMPS (Analysis of Microelectronic and Photonic Structures). Based on the optimized results of single-junction solar cells, we propose a promising method to improve the properties of the dual-junction solar cell. And the monolithic GaAs x P 1−x /Si dual-junction solar cells with various As compositions (x=0.65, 0.75, 0.85) and base thicknesses (t b =0.05∼2.5um) were analyzed. The remarkable conversion efficiency of 35.8% has been obtained for the GaAs 0.75 P 0.25 /Si dual-junction solar cells, which is higher than previously reported results. Our method and results will provide a significant guidance for the design and manufacture of Si-based dual-junction solar cells.

We report a 1.55μΜ square microcavity laser monolithically integrated on GaAs substrates. The mode characteristics of the microcavity laser are numerically investigated by three-dimensional finite difference time domain method. The dependences of the whispering-gallery modes on the width of the output waveguide and the etching depth are discussed. For the cavity with the side length of 12μm and the output waveguide of 1μm, it is easy to excite whispering-gallery modes around 1.55μm. The mode wavelength is 1542.88nm and the mode Q factor is 2389.23. The Q factor degrades rapidly with the waveguide width increasing and increases with the increasing of the etching depth.

This paper is based on the actual survey data, analyzed the relationship between groundwater and ecological environment in arid and semi-arid area, pointed out that groundwater in the arid and semi arid areas boasts not only the resource properties and economic value, but also the important ecological value. The ecological value of groundwater is reflected in four aspects: the maintenance of base flow in rivers, lakes and wetland coverage; the supply of physiological water demanded by vegetations; the mediator of soil moisture and salt content and the watchdog of the stability of geological environment (such as land subsidence, etc.). On this basis, the present paper forms the concept of ecological value of groundwater, and constructed the threshold system between supervened ecology and such multi-dimensional indexes as groundwater table, water quality, water and salt content in vadose zone, groundwater exploitation in arid and semi arid areas, thus providing a scientific basis and technological support for the regulation of the state of groundwater and the maintenance of a virtuous circle of ecological environment and sustainable development and utilization of water resources.

Junggar basin, located in the northwest arid areas of China, has vulnerable supergene ecological environment because of natural and anthropic factors. In this paper, based on the relationship between groundwater and ecological environment and combined with natural and geographical conditions, Junggar basin is divided into five ecosystem types: mountain, natural oasis, artificial oasis, natural water and desert. According to the above five ecosystem types, ecosystem zone maps of Junggar basin in 1990, 2000 and 2009 are obtained by interpreting remote sensing images from Landsat based on RS(Remote Sensing)and GIS(Geographic Information System). On the basis of ecosystem zone maps of three periods, evolution law of ecological environment in Junggar basin is concluded and some existing problems of ecological environment, caused by ecological environment change of three periods, are analyzed.

In arid and semi-arid regions, water is a major limited factor to vegetation and environment. To study the influence of membranes on water retention, three homogeneous sand columns with membranes were installed. Keep the height of free water at 5cm above the soil surface of those columns for 3 hours. Experiments results showed that membranes have strong influence on water retention in saturated sand columns. The membranes could slower water movements through the columns and reduce water dynamic parameters such as hydraulic conductivity. So it has an important role in water retention in sand soils, especially in arid and semi-arid regions.

Due to exposed to serious pollution and influence of natural conditions, drinking water safety has become a hotspot issue drawing high attention from the state and government. Yinchuang Plain is in serious quality-induced water shortage. Through investigation and analysis, this paper established a drinking water safety evaluation system from the perspective of headwaters and human health, studying quality and quantity of groundwater, as well as geological protective performance; safety evaluation on groundwater exploration for drinking in Yinchuan Plain was conducted by adopting analytic hierarchy process and overlay and index methods with the help of GIS software platform. The evaluation result has practical significance for groundwater resource protection and groundwater safety supply.