Supplementary document for Optical fiber tip integrated photoelectrochemical sensors - 5676255.pdf

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DataSheet1_Growth in the Economic and Hydraulic Engineering Capacities Drives Water Quality Improvement in the Eastern Region of Nansi Lake, China.docx

Knowledge of the extent of water pollution along a diversion channel is essential for ensuring the security and effectiveness of water diversion projects. Thus, identifying the trends in the water quality and the factors which influence the trends along a diverted river is a prerequisite to ensuring the safety of the water diversion. As an important control unit of the Eastern Route of the South to North Water Diversion Project, the hilly eastern region of Nansi Lake Basin (ENLB) suffers excess water pollution in the water transferred into Nansi Lake during the flood season. The comprehensive pollution index (CPI), the Mann-Kendall trend test and analysis of variances were used to characterize the spatiotemporal variation of water quality in the three main mountainous rivers of the ENLB. The contribution of different factors which influencing the variation of the water quality parameters may be explained using ridge regression analysis. The results showed that the CPI for the three major rivers decreased significantly from 2000 to 2012. The rivers had problems in compliance, and this was most noticeable in the Guangfu River. The main pollutants exceeding the water quality standards were the chemical oxygen demand and total phosphorus. The GDP per capita was the largest factor which influenced the changes in the regional water quality, with the average contribution being 30%. An increase in the water storage capacity was shown to have a positive effect on improving the water quality. The results provided a scientific basis for establishing a regional pollution control strategy and would give support to the planning of future water diversion projects.</p

Ultracompact Multicore Fiber De-Multiplexer Using an Endface-Integrating Graphene Photodetector Array

The use of multicore fiber (MCF) aims to increase the fiber density with downsized fiber systems, which is constrained by a de-multiplexer with a large footprint that converts the MCF into numerous single-mode fibers and corresponding number of infrared photodetectors. In this study, we demonstrate an ultracompact seven-core fiber de-multiplexer by integrating a patterned single-layer graphene (SLG) photodetector array on a single fiber endface. An optimized electrode configuration was successfully fabricated with a strongly asymmetrical structure on patterned SLG. Owing to the efficient photocarrier separation at the built-in electric field across the metal-doped junction in graphene, we realized self-powered seven-core photodetection using the device. Remarkably, our device exhibits a coupling-free, miniaturized device volume with zero power consumption, a high transmittance, and low manufacturing cost. This device downsizes traditional bulky receiver modules to the micrometer scale with an atomical thickness, which may inspire the development of next-generation highly integrated optical and optoelectronic systems

Stacked polarimeters with twisted black phosphorus

The real-time, in-line analysis of light polarization is critical in optical communication networks, which suffers from the complex systems with numerous bulky opto-electro-mechanical elements tandemly arranged along optical path. Here, we propose a fiber-integrated polarimeter with nano-thickness by vertically stacking three two-dimensional (2D) materials based photodetection units. We demonstrate a self-power-calibrated, ultrafast, unambiguous detection of linear (LP) and circular polarized (CP) light according to the symmetry broken induced linear photogalvanic effects (LPGE) and circular photogalvanic effects (CPGE) in black phosphorous (BP) units, which are twistedly stacked to substitute traditional mechanical rotation of polarizers. As a demonstration, we achieve Hadamard single-pixel polarimetric imaging by the polarimeter to recognize the polarization distributions, showing potential in high-speed polarization-division-multiplexed imaging and real-time polarized endoscopy. This work provides a new strategy for next-generation ultracompact optical and optoelectronic systems, and guides a way for developing high-resolution arrayed devices with multifunctional pixels