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A self-supported carbon electrode consisting of 2D ultrathin heterostructures of NiCo LDH/NiCoS exhibits superior performance for glucose and H2O2 sensing.

The state of polarization (SOP) in a polarization-maintaining fiber subjected to external stress is studied using the quaternion method. The stress principal axis on the Poincare sphere is independent of intrinsic birefringence, but has a linear relationship with the direction of external stress. The above linear relationship, in turn, enables a measurement of the external stress's direction by calculating the consecutive trajectory of SOP on the Poincare sphere. This method is proposed and experimentally validated by measuring different types of fibers with maximum angle measurement errors of less than 2.24%.

In this paper, the progress of the stress sensor based on Polarization Maintaining Fiber (PMF) is reviewed, and point out that the joint multi-effect of internal and external effects in PMF based sensor is a basic phenomenon, and the study on multi-effect have important academic value and application prospects. A quaternion approach to study on the multi-effects of PMF sensor is proposed, and the cosines law on the multi-effects is presented and proved. Theoretical analysis and simulation based on the theorem are given. The experiments to demonstrate the multi-effect is designed and related results proved the correctness of the cosines law of joint multi-effect.

Using a quaternion method, the polarization mode-coupling coefficient can be derived from three components of the Stokes vectors at three adjacent points along a fiber. A complete polarization optical time-domain reflectometry scheme for polarization mode coupling distributed measurement in polarization-maintaining fiber ring is proposed based on the above theoretical derivations. By comparing the measurement results of two opposite incident directions and two orthogonal polarization axes of polarization-maintaining fiber rings with different lengths, the feasibility and repeatability of the measurement scheme are verified experimentally with a positioning spatial resolution of 1 meter.

In this brief paper, based on multiplex visibility graphs technique, a simple and fast computational method was proposed to fulfill converting high dimensional timeseries into a multiplex graph with different characters. The constructed multiplex graph inherits several properties of the time series in its structure. Thereby, periodic series, random series, and chaotic series convert into quite different multiplex networks with different average degree, characteristic path length, diameter, clustering coefficient, different degree distribution, and modularity, etc. By means of this new approach, with such different networks measures, one can characterize multivariate timeseries from a new viewpoint of complex networks.

Blind source separation (BSS) is implemented for optical fiber sensing systems, such as the fiber Bragg grating (FBG) sensing system and the single-mode-multimode-single-mode fiber (SMS) sensing system. The FastICA, a kind of multichannel BSS algorithm, is used to get the strain and the temperature with two FBGs. For the SMS sensing, a single-channel blind source separation (SCBSS) algorithm is employed to simultaneously measure the vibration and the temperature variation with only one SMS sensor. The errors of both the FBG and the SMS optical fiber sensing system are very small with the BSS algorithm. The implementation of BSS for the optical fiber sensing makes the multiparameter measurements more easily with low cost and high accuracy and can also be applied for signal de-noising field.

Briefly compare the polarization rotation speed of Mach-Zehnder interferometer, lithium crystal, LCD and semiconductor optical amplifier (SOA), etc. Then propose a program of high-speed ternary optical multiplier based on SOA’s nonlinear polarization rotation. Finally, the theoretical analysis and simulation research of SOA’s nonlinear polarization rotation indicate that the ternary optical multiplier is one of the possible options to achieve high-speed optical computing, and may be widely applied to optical computer.