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A polarization splitter based on dual-core photonic crystal fiber (PCF) with tellurite glass was proposed. The birefringence of the splitter was improved by introducing elliptical air holes. The full vector finite element method is used to analyze the impacts of structural parameters on the coupling length. The results show that the elliptical size is reasonably changed, the extinction ratio can reach 107.21 dB at the wavelength of 1.55 μ m , the length of the splitter is 89.05 μ m , and the bandwidth is 150 nm when the extinction ratio is more than 20 dB. Besides, we also compare the characteristics of tellurite glass and silica glass photonic crystal fiber polarization beam splitters with the same structural parameters.

CFRP laminates are used for various aircraft structural components because of their good mechanical and physical properties. Metallic inserts are one kind of aerospace fasteners, which are usually installed in the metallic components by an interference fit. However, when metallic inserts are installed in the CFRP laminates by the traditional installing way, delamination and low efficiencies are troublesome. Therefore, excellent quality and cost effective installing metallic inserts into the CFRP laminates remains a challenge. In this paper, a series of experiments were carried out to study the compatibility for metallic inserts bonded into the CFRP laminates soaked in the aircraft fuel. The experimental results show that the push-out values and breakaway torque values of metallic inserts bonded in the CFRP laminates soaked in the fuel are not reduced compared with these values of sample was not prepared in that way.

A new kind of dual-core photonic crystal fiber polarization splitter based on tellurite glass is designed by introducing five elliptical air holes and octagonal lattice into the polarization splitter. The full vector finite element method and coupled-mode theory are used to study its characteristics. The structure parameters are optimized through the study of all parameters in the split structure. The results show that a polarization splitter with a short length of 105.156 μm can completely separate the two beams of polarization lights. And at the wavelength of 1.550 μm the extinction ratio can reach 124.920 dB. Meanwhile, the bandwidth is 165 nm when the extinction ratio is more than 20 dB and the wavelength range is from 1.467 to 1.632 μm, which covers the S + C + L wavelength bands. The bandwidth is 448 nm when the extinction ratio is more than 10 dB and the wavelength range is from 1.322 to 1.770 μm. The polarization splitter has a short length and a high extinction ratio and a wide bandwidth, which can be widely applied in large-capacity and integrated optical communication systems.

This paper aims to investigate orbital drilling process in carbon-fiber reinforced plastic (CFRP) composites with multi-point orbital drilling tool based on the robot automatic drilling system. One orthogonal experiment has been carried out, and the cutting forces of different parameters were measured online by dynamometer. Furthermore, the cutting force model was established through regression analysis, and the impacts of cutting parameters on thrust force were deeply analyzed. In addition, delamination and tear defects were inspected respectively, and the relationship between thrust force and delamination and tear was discussed. Our results indicate that thrust force increased with the increasing feed rate and axial feed depth, while decreased with the increasing spindle speed. Axial feed depth was found as the predominant factor on thrust force and defects. At last, the cutting parameters was optimized and then thrust force decreased more than 26% with almost none tear and burr around the hole, which indicates a better machine quality.

Zinc oxide (ZnO) nanocrystalline with different morphologies, used in ultraviolet (UV) light detection, was successfully fabricated by directly oxidizing metallic zinc at high temperature. X-ray diffraction spectra show that the as-prepared samples are hexagonal wurtzite structure. Scanning electron microscopy images indicate that ZnO with different morphologies such as comb-like, tetrapod and bullet structures could be controlled by simply variables like gas flow rate, ambient pressure and growth temperature. The Photoluminescence (PL) spectra were employed to reveal native point defects in ZnO nanocrystalline. The UV detection properties of ZnO nanocrystalline films screen-printed on interdigital electrodes were investigated by observing the changes of capacitance and conductance under different light sources. The results indicate that the comb-like ZnO nanocrystalline has high UV sensitivity.

Zhan-Qiang HuiXi’an University of Posts and TelecommunicationsSchool of Electronic EngineeringXi’an 710061, ChinaEmail: zhanqianghui@xupt.edu.cnJian-Guo ZhangLondon South Bank UniversityDepartment of Engineering and Design103 Borough RoadLondon SE1 0AA, United KingdomJia-Min GongMeng LiangMei-Zhi ZhangYi YangFeng-Tao HeJi-Hong LiuXi’an University of Posts and TelecommunicationsSchool of Electronic EngineeringXi’an 710061, ChinaAbstract. We propose and experimentally demonstrate all-optical return-to-zero (RZ) to nonreturn-to-zero (NRZ) format conversion by using multi-ple cross-phase modulation (MXPM) in a highly nonlinear fiber. The pro-posed all-optical format converter can perform simultaneously wavelengthconversionanddual-channelsignalmulticasting.Thisisachievedbyprop-erly filtering two broadened probe spectra induced by MXPM between theRZ signal and continuous-wave double probe lights. We also study exper-imentally wavelength tunability for the proposed format converter at40 Gbit∕s, which is feasibly achieved by varying the central wavelengthsof the double probe lights. Our results show that a wide operation wave-length range of 24 nm is obtained. By monitoring eye diagrams, the con-verted 40 Gbit∕s NRZ signals can have an extinction ratio of 10.9 dB andthe