Journal of Applied physics,Vol.33 : 1962年に発表されたレオロジー関連の論文

(IEEE Transactions on Electron Devices,36(12):2816-2820)Field-Drifting Resonant Tunneling Through a-Si:H/a-Sil-xCx:H Quantum Wells at Different Locations of the i-Layer of a p-i-n Structure

Optical Engineering Core 28 hours CPE 112 3 Intro To Computer Programming MA 113, MA 115, or Level III placement FSM EE 307 3 Electricity and Magnetism EE 300 FSM EE 313 3 Electrical Circuits II Preor co-requisite: EE 307 FSM EE 447 3 Electromagnetic Waves EE 313 S OPE 453 3 Laser Systems EE 307 F OPE 455 2 Optical Engineering Laboratory PH 113, OPT 342, EE 382 or OPT 442 S OPE 459 3 Optical Engineering Design ISE 321, Senior standing S OPT 341 3 Geometrical Optics PH 113 F OPT 342 3 Physical Optics OPT 341 S OPT 411 2 Geometrical Optics Laboratory PH 116, OPT 341, OPE 441 suggested co-requisite F

海外文献紹介 Optical Engineering

https://onlinelibrary.wiley.com/doi/pdf/10.1002/pssr.202100113

68.9% Efficient GaAs-Based Photonic Power Conversion Enabled by Photon Recycling and Optical Resonance

This article demonstrates a fiber-based power-by-light system that is capable of delivering up to 6.2 W of continuous electrical power at common voltages of 3.3 and 5 V. This optical link includes bidirectional optical communication, for which the data stream from the base to the remote unit is realized by amplitude modulation of the laser beam over the same fiber. At the remote unit, a gallium arsenide-based photovoltaic (PV) laser power converter receives and converts the light. The data are demodulated with a dedicated electric circuit, while the power is forwarded to a dc–dc boost converter. The optical data uplink is realized over a separate optical fiber. In operation, a PV conversion efficiency of above 50% has been measured. For downlink data rates up to 115.2 kb/s, unperturbed signal integrities are demonstrated, at higher data rates, the signal integrity deteriorates. An assessment of power budget and power losses in the overall system is presented. Finally, a smart power management concept is introduced, which controls the laser output power with respect to changing electrical load, optimizes the operating point of the PV cell, and, thus, increases system efficiency for varying load operation. Thereby, it also minimizes laser and PV cell operating temperatures, and eventually prolongs the lifetime of the system.

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6-W Optical Power Link With Integrated Optical Data Transmission

Blade condition monitoring systems with fiber-optic sensors attract much attention because they are resistant to lightning strikes, a major issue with increasing blade lengths. However, fiber-optic sensor systems are more complex and more expensive than their electronic counterparts. We describe a new blade condition monitoring system, which combines the lightning safety of optical fibers with the reliability and cost-effectiveness of electronic sensors. The optical fibers transport data from the blades to the hub, and in addition, they provide the electrical power for operating the sensor units in the blades. To achieve full protection against lightning-induced electromagnetic fields, an appropriate shielding of the sensor units is required. We present results on the reliability of a newly developed prototype based on optically powered sensors. In a field trial, the unit monitored successfully the blade vibrations of a 1.5 MW wind turbine for a period of 23 months. Copyright © 2016 John Wiley & Sons, Ltd.

Reliable and lightning‐safe monitoring of wind turbine rotor blades using optically powered sensors

A new I-V measurement set-up called LaserSim has been developed for photovoltaic laser power converters – photovoltaic cells optimized for monochromatic artificial light providing irradiances of up to 89 W/cm2. The evaluation of the set-up and first I-V curve and efficiency measurements are presented. Similar to flash simulators used for I-V characterization of solar cells, the LaserSim is using transient measurement routines to avoid an influence of heating of the samples during measurement. An excellent light uniformity in the designated test area was realized. A beam sampler allows for in-situ irradiance determination while recording I-V data. This is mandatory for characterization of devices showing a non-linear behavior of short circuit current with irradiance. Efficiency values under monochromatic light at 809 nm have been measured for a single junction GaAs cell (55.6 %) and a dual-junction GaAs device (53.5 %).

Transient I-V Measurement Set-Up for Photovoltaic Laser Power Converters under Monochromatic Irradiance

An elegant solution for the power supply of sensor electronics is the application of power-by-light technology. With this technology several challenges related to conventional copper wiring are inherently overcome; benefits are galvanic isolation, the suppression of electromagnetic interference, and the possibility to combine power and bidirectional data transmission in a single fiber link. In order to power sensor electronics efficiently, a supply voltage in the range 3 to 12 V is typically required. This paper deals with the photovoltaic laser power converter used to convert the transmitted optical power back into electricity. The advanced cell concepts of multi-junction and multi-segment cells are discussed which both aim at an increased output voltage on the device level, thereby eliminating the need for additional DC/DC conversion. Modeling and experimental results of GaAs based cells are presented, namely of single-junction 2- to 12-segment cells as well as of a dualjunction single-segment structure. A discussion of the pros and cons of the different concepts is given, focusing on the consequences of misalignment and temperature changes.

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D1.4 - Photovoltaic Cells with Increased Voltage Output for Optical Power Supply of Sensor Electronics

We demonstrate a prototype of a lightning-safe system for condition monitoring of wind turbine rotor blades The system uses non-conductive optical fibers instead of copper cables for powering remote electrical sensor units and for exchanging data with them Thus, complete electrical isolation between the sensor units inside the rotor blades and a base station in the hub of the wind turbine is provided Optical power delivered by fiber-coupled laser diodes is converted at each sensor unit into electrical power by a miniature photovoltaic cell, making 177 mW available to continuously operate a two-axes MEMS acceleration sensor as well as a low-power microcontroller (muC) for data processing Sensor data are sent back to the base station through a fiber-optic transmitter We successfully tested the prototype for an extended 4-month field trial inside a 15 MW wind turbine This work has been realized in the framework of the project OPTOWIND supported by the German Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (BMUB)

S.K. Reichmuth

Papers

Reliable and lightning‐safe monitoring of wind turbine rotor blades using optically powered sensors

Transient I-V Measurement Set-Up for Photovoltaic Laser Power Converters under Monochromatic Irradiance

D1.4 - Photovoltaic Cells with Increased Voltage Output for Optical Power Supply of Sensor Electronics

Lightning-safe Monitoring of Wind Turbine Rotor Blades Using Optically Powered Sensors