查看更多>>摘要：The working temperature of the cable is particularly important for the safe operation of the power system, which requires high temperature detection for its working environment, but the sensitivity of the ordinary optical fiber temperature sensor in the high temperature state cannot meet this demand. For this purpose, an optical fiber high temperature sensor based on ZnO composite graphene temperature sensitive material is developed in this paper. MMF-TSCF-MMF temperature sensing unit is composed of two sections of multimode fiber (MMF) and a tapered seven core fiber (TSCF). Three different shapes of ZnO@Gr (ZnO composite graphene) temperature-sensitive materials were prepared by hydrothermal method. The experimental results show that the sensor has high stability and good interference effect. Meanwhile, the wavelength sensitivity reached 0.33268 nm/degrees C in a temperature measurement range of 89-98 degrees C. The fiber sensor is used for precision temperature measurement of cable temperature in fields such as electrical engineering due to its high temperature sensitivity, small size and low cost.
查看更多>>摘要：The evaluation of beam shape coefficients (BSCs) which encodes the description of the illuminating beam is an essential issue in light scattering theories of spherical particles, such as the generalized Lorenz-Mie theory (GLMT). Different methods have been developed in this context, including the traditional (quadratures, finites series, localized approximations), to be complemented by use of the angular spectrum decomposition (ASD). The present paper is devoted to a comprehensive study of the relationship between the traditional quadrature method and the ASD method to the evaluation of BSCs. We shall establish that evaluation of BSCs using the quadrature method can be modified into expressions in the spectral space, leading to the same results as those obtained using the ASD. These BSCs are afterwards approximated under the paraxial conditions, leading to the same results as these obtained by using the localized approximations. The TEM0l* doughnut beam is taken as an example of the shaped beam and the theoretical analysis is confirmed by numerical calculations.
查看更多>>摘要：Simultaneous wireless laser information and power transfer can be widely used in the Internet-of-Things and energy Internet power supply systems to improve system performance. Herein, a hybrid pulse width modulation (PWM)-based simultaneous wireless laser information and power transfer system using PWM sampling is proposed and is investigated theoretically and experimentally. The output voltage of the receiver is adjusted based on the duty cycle of the PWM loaded on the laser diodes at the transmitter. Communication is achieved by leveraging sampling of the PWM by loading a modulation disturbance on the modulation wave of the PWM generator. An output voltage of 1.5 V, output power of up to 0.75 W, and communication rate of up to 10 kbps are achieved in the proposed system. The system can be applied in one-to-many transmissions of power and signals in microgrid power supply systems, in which signals and power can be loaded on the direct current bus through the proposed system node, such that the signals and power can be transmitted to each powered node without additional signal conditioning, modulation, or coupling. The proposed system can thus enhance the interference immunity of communication subsystems, as well as the simplicity, and safety of power transfer subsystems.
NSTL
Elsevier