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A polarimeter for optical rotation (OR) detection and optical active media measurement based on m=1 Zero-Order Liquid Crystal Polymer Vortex Half-Wave Retarder (LCPVR) and Digital Image Processing (DIP) was proposed in this letter. In this research, we demonstrate the principle of measuring optical rotation with LCPVR polarimeter system which is based on Jones vectors and matrices. Two opposing wedge-shaped dark areas will appear in the output image when the uniform distribution polarized light passes the LCPVR. DIP is used to find the darkest line in the opposing wedge-shaped dark areas, then the optical rotation angle is calculated, which is from −90 degree to +90 degree. The polarimeter is used to measure the concentration of sucrose solutions at the range of 1000-10000mg/dl L. We also present the fabricated method of LCPVR by Digital Micro-mirror Device (DMD) system, and the LCPVR will be low price in the fabricated processing. Compared with existed polarimeter, our polarimeter with LCPVR has simpler optical structure and less size. The key innovation of this system is that the optical rotation angle can be displayed with visualized image except digital. And the rotation angle is calculated by DIP without mechanical adjust a 1/4 wave plate, which lead to higher detection speed and stronger stability.

As a new wireless access technology, Narrow Band IoT (NB-IoT) enables low-power wide-area coverage services and can be applied to many domains. Emerging applications such as smart traffic, shared bicycles and shared cars have put forward more stringent requirements for connectivity. In order to get higher QoS, an enhancement access algorithm is proposed for the complex service scenario of NB-IoT, in which the network terminals are clustered based the distance from base station and terminal traffic intensity, and allocated reuse preamble code to improve network access capacity. The capacity is modeled and analyzed to evaluate the enhanced access algorithm based on clustering-reuse preamble allocation (ERA-CRPA). The experimental results show that the ERA-CRPA can effectively reduce the probability of random access preamble collision, further improve the access efficiency and increase the equivalent capacity of NB-IoT network.