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[IEEE 2018 Asia Communications and Photonics Conference (ACP) - Hangzhou, China (2018.10.26-2018.10.29)] 2018 Asia Communications and Photonics Conference (ACP) - CO<inf>2</inf> Laser Inscribed Helical Long-Period Grating in Six-Mode Fiber
摘要： We fabricated the helical long-period fiber grating in a six-mode fiber with CO2 laser. The grating realize mode conversion from LP01 mode to LP21 mode with high efficiency. The mode coupling and sensing characteristics are investigated.
关键词： six-mode fiber,Helical long-period grating,mode converter
更新于2025-11-28 14:24:03
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A MEMS BPSK to ASK converter
摘要： Purpose – The purpose of this paper is to investigate the feasibility of using micro electromechanical systems (MEMS) to convert a binary phase shift keying (BPSK) signal to a simpler amplitude shift keying (ASK) scheme. Design/methodology/approach – The prototype is designed within the SOIMUMPs? fabrication process constraints. The fabrication constraints imposed geometric limitations on what could be tested. These constraints were used to build a mathematical model, which in turn was used to optimize the response using MATLAB?. The optimized design was tested using ?nite element analysis with CoventorWare?, and ?nally lab tests on the fabricated device were performed to con?rm theoretical predictions. Findings – Theoretical predictions compared well with lab measurements on a prototype device measuring 2.9 mm2. The prototype was tested with a carrier frequency of 174 kHz at a BPSK data rate of 3 kHz and carrier amplitude of 6 V. With these parameters, ASK modulation indices of 0.96 and 0.94 were measured at the two output sensors. Originality/value – This study provides a MEMS solution for BPSK to ASK conversion. The study also identi?es what limits betterment of the modulation index and data rate. Such a device has potential application in wireless sensor network (WSN) nodes that have energy harvesters and sensors that are also built in MEMS. Being a MEMS device, it can facilitate integration in such WSN nodes and, hence, potentially reduce size and costs.
关键词： Modulation index,Mixer,ASK detector,Micro electro mechanical systems (MEMS),BPSK converter
更新于2025-11-14 17:28:48
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Soft tissue cutting efficiency by 980?nm laser with carbon-, erbium-, and titanium-doped optothermal fiber converters
摘要： Objectives: The use of near-IR diode lasers for contact soft tissue surgery is attended by a risk of severe thermal damage of surrounding tissues due to the low cutting efficiency of these lasers. To increase the cutting efficiency tips of a near-IR lasers in contact surgery special (converters) which transform laser light to heat are used. The present in vivo study evaluated temperature dynamics and soft tissue cutting efficiency of 980 nm diode laser equipped with standard carbon- and novel erbium- and titanium-doped converters. Materials and Methods: For in vitro treatment on soft tissue (chicken thigh), 980 nm diode laser was used. The radiation was delivered to the tissue by a quartz fiber with a core diameter of 400 ± 5 mm. The carbon-, erbium-, or titanium-doped converters were mounted at the fiber distal end. The converters temperature was measured by IR-sensor integrated into the laser radiation delivery system. The temperature dynamics of each converter during soft tissue treatment was evaluated. The converter was in contact with the soft tissue surface and moved across the surface of soft tissue with a speed of 1, 3, or 6 mm/s. The average power of laser radiation was 0.3, 1.0, or 4.0 W. The collateral thermal damage of treated soft tissues was evaluated using NTBC stain. The width and depth of coagulation and ablation zones of laser wounds was determined. The soft tissue cutting efficiency with different converters was calculated. Results: The cutting efficiency, collateral damage, and converter temperature in contact with soft tissue change depending on the type of converter, the power of laser radiation and the converter movement speed along the temperature tissue (1,980 ± 154 °C), at which a tissue cut takes place, was fixed for Ti-doped converter for laser power of 4.0 W and movement speed of 1 mm/s. Minimal converter temperature (540 ± 30 °C), at which a tissue cut takes place, was fixed for Ti-doped converter for laser power of 1.0 W and movement speed of 6 mm/s. Maximal depth of coagulation (0.72 ± 0.10 mm) was fixed for Ti-doped converter for laser power of 4.0 W and movement speed of 1 mm/s. Minimal depth of coagulation (0.11 ± 0.02 mm) was fixed for C-doped converter for laser power of 0.3 W and movement speed of 3 mm/s. Maximal cutting efficiency (0.57 mm3/W) was fixed for Er-doped converter for laser power of 1.0 W and movement speed of 1 mm/s. Minimal cutting efficiency (0.02 mm3/W) was fixed for C-doped converter for laser power of 4.0 W and movement speed of 6 mm/s. Conclusion: All three studied types of converters can be used for contact surgery of soft tissues by 980 nm diode laser. Er-doped and Ti-doped converters are more resistant to laser heating then C-doped converter, they dissect soft tissue more effectively. This will also expand the potential of everyday routine clinical procedures, making them safer, faster, and easier. These converters can be used in general surgery, plastic surgery, dermatology, angioplasty, dentistry, neurosurgery, etc. Lasers Surg. Med. 9999:1–16, 2018. ? 2018 Wiley Periodicals, Inc.
关键词： soft tissue,coagulation,surgery,efficiency,IR-sensor,diode laser,cutting,converter,fiber
更新于2025-10-24 16:41:07
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An analog-to-digital converter and intelligent controller for use in a DAQ system processing PMT signals from very high energy astrophysics experiments
摘要： Modern instrumentation for very high energy gamma-ray astronomy and astrophysics requires efficient and precise digitisation of PMT signals from Cherenkov light generated by incoming cosmic ray particles over the energy range from hundreds of GeV up to several hundred TeV. This dynamic range of more than 1000 is coupled with a requirement for very low noise operation. We have developed modern multi-channel analog-to-digital converters (model BPA-8) together with a data acquisition system managed with an intelligent crate-controller (model K-167) which controls the measurement modules. The electronics described in this paper is accepted to be used to record PMT signals with high precision and efficiency, allowing reliable extraction and precise analysis of Cherenkov signals from high energy gamma-rays emitted by astrophysical objects.
关键词： intelligent crate-controller,astroparticle detectors,analog-to-digital converter
更新于2025-09-23 15:23:52
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[IEEE 2018 2nd International Conference on Trends in Electronics and Informatics (ICOEI) - Tirunelveli, India (2018.5.11-2018.5.12)] 2018 2nd International Conference on Trends in Electronics and Informatics (ICOEI) - Highly Efficient Constant Power Generation Using Solar Tree
摘要： In the solar system which is connected to the grid; it is essential to select reliable and efficient solar converter and inverter with higher efficiency. The electrical converter ought to management the injecting power to the inverter and the inverter ought to be in the position to control the injecting power to the grid. This paper discusses an efficient concept of solar power generation called as Solar Tree and also the ZVT-ZCT-PWM boost converter topology and HERIC inverter topology for highly efficient system. Also we have done a simulation for this system which has desirable results.
关键词： Solar Tree,PV system,ZVT-ZCT-PWM boost converter,HERIC inverter
更新于2025-09-23 15:23:52
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[IEEE 2018 International Conference on Power, Energy, Control and Transmission Systems (ICPECTS) - Chennai (2018.2.22-2018.2.23)] 2018 International Conference on Power, Energy, Control and Transmission Systems (ICPECTS) - Design and Hardware Implementation of Self Lift Negative Output Luo Converter Using MPPT for PV Applications
摘要： The design and analysis of self lift N/O luo converter is discussed in this paper. The incremental conductance mppt extracts the maximum power from PV panel and transfers to the load. The PV panel is designed by using equivalent circuit of PV cell. The output obtained from the solar panel contains more ripples. The ripples will produce more fluctuations. By using self lift negative output luo converter the unregulated output will be conveted into regulated voltage and stepped up to the higher voltage. For obtaining simulation results Matlab software is used.
关键词： Incremental conductance (IncCond) Maximum Power Point Tracking (MPPT) algorithm,self lift negative output luo converter,Photovoltaic system
更新于2025-09-23 15:23:52
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Comparative Study on Solar Powered Interleaved Boost Converter
摘要： Solar energy is an important source of renewable energy. But, it is unpleasant that, only partial amount of energy can be extracted from the Solar cells by our conventional DC-DC Boost converters. A comparative study on solar powered Interleaving Boost converters (ILBCs) is initiated. A novel Solar powered, Series-Inductor ILBC with less current ripple than the conventional ILBC is proposed. A comparative study on single- stage, two-stage and three-stage ILBCs are done. The comparison of ripple reduction of output voltage is tried with ‘C’, ‘Pi’ and Cascade Filters. The results have been applied to R-Load and motor load. The input of 150V is fed to the ILBC from the solar cell and compared for the ripple. The proposed solar powered series inductor ILBC has reduced ripple than the conventional ILBCs. Comparison table of performance and simulation results of these aforementioned solar powered ILBCs have been exhibited in this paper.
关键词： Interleaving,Boost Converter,Solar Power,Comparison Study
更新于2025-09-23 15:23:52
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Theoretical research on obtaining of picoseconds dilated pulses with a framing imaged converter tube
摘要： Variations in the temporal resolution of a pulse-dilation framing imaged converter tube (FICT) were studied. The relation between temporal resolution and dilated pulse was analyzed. The computational methods for describing pulse gradient and time-varying amplitude were derived. It explores the possibility of obtain picoseconds ultrafast pulses and the others potential application FICT from a theoretical perspective. The results show that it is higher precision to achieve the shape and amplitude of an ultrafast dilated pulse using a FICT. The relative standard deviation (RSD) range of ten thousand sample data was 5.8% when the time step is 50 ps, and the RSD is reduced to 1.9% as the time step is shortened to 10 ps. We expect that our results will expand the others potential applications of FICTs and provide that a theoretical basis for further optimizing relevant external systems of FICT.
关键词： ultrafast diagnostic,picoseconds pulse,pulse-dilation,framing imaged converter tube
更新于2025-09-23 15:23:52
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Dark current in long-wave cascade-transport infrared up-converters
摘要： Reducing the dark current in an infrared (IR) photodetector is one of the most important aspects in improving the detector’s performance. This article attempts to clarify the dominant paths of dark current and reduce it in a long-wave cascade-transport IR up-converter (CIUP), which has been reported to be a potential candidate for very-large-scale IR detection/imaging. The four paths of the dark current are considered, including the ground state sequential tunneling, thermionic emission onto the continuum, thermally-assisted transition onto the excited state of the absorption quantum well (QW) or some energy levels in the transport region. Accordingly three designs of the band structure are proposed for long-wave CIUPs, with miniband-to-miniband intersubband transition, bound-to-miniband transition and step-bound-to-miniband transition. Samples based on these designs are fabricated and measured. Both the calculated electron concentration distributions and the measured dark currents show that the step-bound-to-miniband structure is the most effective in cutting down the dark current, in which the superlattice barrier and InGaAs absorption QWs help to reduce dark current related to tunneling, thermionic emission and thermally-assisted tunneling.
关键词： Dark current,Up-converter,Step-bound-to-miniband,Long-wave infrared,Cascade
更新于2025-09-23 15:23:52
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Coordinated control of MPPT and voltage regulation using single-stage high gain DC–DC converter in a grid-connected PV system
摘要： In general, grid-connected PV system uses two stages of DC-DC converter to accomplish Maximum Power Point Tracking (MPPT) and DC voltage regulation. In order to overcome the two stage conversion, a single stage high gain DC-DC converter is presented in this paper. The operation of three switches with two different duty ratio is the main advantage of this converter to accomplish the coordinated control of MPPT and DC voltage regulation. This coordinated control also helps to provide constant DC voltage to the DC loads though the inverter is disconnected from the DC bus. A 1KW grid-connected PV system with the proposed DC-DC converter is developed and is validated using OP4500 Real-Time test platform. In addition, a decoupled control strategy with fractional order proportional-integral (FOPI) controller is implemented at the inverter end. Also, the reactive power compensation, harmonic reduction (less than 5% as per the IEEE 519 standard) and the grid power factor close to unity is obtained and the results are validated using the real-time simulator.
关键词： Solar photovoltaics,LCL filter,Coordinated control of MPPT and voltage regulation,High gain DC-DC converter,Grid integration and power quality
更新于2025-09-23 15:23:52