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- 2019
- Mach Zehnder Interferometer
- Convolution code
- Lithium Niobate
- Parity
- Electro-optic
- Optoelectronic Information Science and Engineering
- DIT University
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[IEEE 2019 10th International Conference on Computing, Communication and Networking Technologies (ICCCNT) - Kanpur, India (2019.7.6-2019.7.8)] 2019 10th International Conference on Computing, Communication and Networking Technologies (ICCCNT) - Electro-Optical Design and Modeling of Convolutional Code Encoder
摘要： Error detection using electro-optical methods has evolved as a new research domain in the recent years. They have proved to be more reliable than the conventional electronic methods. The presented paper describes the design and analysis of an electro-optical convolutional code encoder. The convolutional code has been long in use for the efficient detection of errors. The design has been proposed using Lithium Niobate based Mach-Zehnder Interferometer. The code bits are generated by modulo-2 addition of the input data in different patterns by the use of shift register and XOR gate. The design has successfully been tested using the beam propagation method. The calculated extinction ratio (24.82 dB), insertion loss (0.11 dB) and contrast ratio (23.26 dB) are meeting the desired values for the better performance of the device.
关键词： Mach Zehnder Interferometer,Convolution code,Lithium Niobate,Parity,Electro-optic
更新于2025-09-16 10:30:52
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Economic and environmental assessment of reusing electric vehicle lithium-ion batteries for load leveling in the residential, industrial and photovoltaic power plants sectors
摘要： Reaching 70–80% of primary capacity, lithium-ion batteries must be replaced in electric vehicles. However, they could be reused in other applications such as energy storage stations. In this paper, an economic evaluation of reusage of lithium-ion packs for load leveling in the residential, industrial and photovoltaic power plants sectors have been investigated from subscriber and government aspects. Several repurposed electric vehicle battery packs have been taking into account for different tariffs and scenarios. It is found that utilization of battery can reduce electricity bill for residential consumers by 14.25% based on the current electricity market and 39.75% if the fine of the peak time consumption is tripled. However, the current subsidy rate in the electricity tariffs is the main barrier in terms of the payback period for homeowners. Moreover, it is found that decrease in the battery prices by 2035 as the only factor will not justify usage of repurposed battery in residential sector, furthermore, tariffs must also be regulated. Sensitivity analysis declared that a 20% reduction in the price of battery in residential sector, affects the internal rate of return by 164%. Meanwhile, increasing in the on-peak tariff can fluctuate it by 44%. Reusing electric vehicle batteries could be more profitable in the industrial sector due to the realistic tariff. In addition to the operation cost, government saving is analyzed from the initial cost aspect. Results illustrated that utilization of repurposed battery packs can reduce construction costs of new on-peak thermal power plants by 72.5% and 82% in the residential and industrial sectors, respectively. Finally, the effect of using repurposed lithium-ion battery packs on the emission rates of greenhouse gases and other air pollutants are surveyed. The reused batteries can be employed to achieve sustainable development.
关键词： Load leveling,Secondary use,Lithium-ion battery,Environmental analysis,Electric vehicle,Economic analysis
更新于2025-09-16 10:30:52
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Good-Quality and High-Efficiency Dicing for Thick LiNbO3 Wafers Using Picosecond Laser Pulses
摘要： Lithium niobate (LiNbO3) has become popular with applications in electronics and communication industries due to its excellent electro-optical and nonlinear properties. This paper presents the influence of laser power, repetition frequency, number of subpulses, depth of each pass, and scanning velocity in picosecond laser dicing on multiple characteristics of LiNbO3 using the Taguchi method. By means of analysis of variance and analysis of relations between the characteristics, the optimal ps-laser-dicing parameter is obtained with good quality and high efficiency, which is applied to LiNbO3 products. The result indicates that picosecond laser dicing provides an alternative to machine thick LiNbO3 wafers with narrow kerf width, micro chipping, smooth surface, and high productivity.
关键词： thick lithium niobate,picosecond laser,LiNbO3 wafers,laser dicing,dicing quality optimization
更新于2025-09-16 10:30:52
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Improving the Reliability of Photovoltaic and Wind Power Storage Systems Using Least Squares Support Vector Machine Optimized by Improved Chicken Swarm Algorithm
摘要： In photovoltaic and wind power storage systems, the reliability of the battery directly affects the overall reliability of the energy storage system. Failed batteries can seriously affect the stable operation of energy storage systems. This paper aims to improve the reliability of the storage systems by accurately predicting battery life and identifying failing batteries in time. The current prediction models mainly use artificial neural networks, Gaussian process regression and hybrid models. Although these models can achieve high prediction accuracy, the computational cost is high due to model complexity. Least squares support vector machine (LSSVM) is a computationally efficient alternative. Hence, this study combines the improved chicken swarm optimization algorithm (ICSO) and LSSVM into a hybrid ICSO-LSSVM model for the reliability of photovoltaic and wind power storage systems. The following are the contributions of this work. First, the optimal penalty parameter and kernel width are determined. Second, the chicken swarm optimization algorithm (CSO) is improved by introducing chaotic search behavior in the hen and an adaptive learning factor in the chicks. The performance of the ICSO algorithm is shown to be better than CSO using standard test problems. Third, the prediction accuracy of the three models is compared. For NMC1 battery, the predicted relative error of ICSO-LSSVM is 0.94%; for NMC2 battery, the relative error of ICSO-LSSVM is 1%. These findings show that the proposed model is suitable for predicting the failure of batteries in energy storage systems, which can improve preventive and predictive maintenance of such systems.
关键词： chaotic search,least squares support vector machine,chicken swarm optimization algorithm,storage system,sustainable lithium-ion battery
更新于2025-09-16 10:30:52
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Luminescence varied by selective excitation in Eu3+,Tb3+-doped LiSrPO4 phosphors for W-LEDs applications
摘要： Tb3+ and Eu3+-doped LiSrPO4 (LSPO) were produced via a modified sol-gel route. Structural and optical characterization was performed by X-ray diffraction (XRD) and photoluminescence spectroscopy (PL), respectively. The results reveal that the presence of dopants has an effect on the LSPO structure. PL spectra of the LSPO:Tb, Eu (LSPOTE) phosphor consisted of major emission lines associated with 5D3,4-7FJ (J = 3, 4, 5 and 6) and 5D0-7FJ (J = 0, 1, 2, 3 and 4) transitions of Tb3+ and Eu3+ ions, respectively. A change in emission spectra was observed when the excitation wavelength was changed. Under middle-ultraviolet excitation (227 nm), the Tb3+ and Eu3+-doped LiSrPO4 phosphor exhibited white emission. The results suggest that the LiSr0.97PO4:Tb0.01,Eu0.02 phosphors prepared in the present work could be used in combination with AlGaN chips to fabricate white LEDs.
关键词： Terbium,Lithium strontium orthophosphate,Europium,White LEDs
更新于2025-09-16 10:30:52
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Lithium-Ion Capacitor for Photovoltaic Energy System
摘要： A design of photovoltaic energy system consisting of a solar panel and hybrid supercapacitor is discussed. The application of lithium-ion capacitor in photovoltaic energy system is considered to be a novel promising way in order to fill up the gap between the specific energy, power and service life of the battery and supercapacitor. In this work there was developed an advanced lithium-ion capacitor that can provide both a sufficiently high energy density and the increased power density and service life. Developing the lithium-ion capacitors, the capacity of cathode can vary over a wide range, reaching the value required for the optimum photovoltaic energy system performance.
关键词： photovoltaic energy systems,supercapacitors,batteries,lithium-ion capacitors,hybrid electrochemical capacitors
更新于2025-09-16 10:30:52
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Three‐stage kinetics of laser‐induced LiFePO <sub/>4</sub> decomposition
摘要： This paper reports about new insight into a problem of a laser–matter interaction during Raman probing of lithium iron phosphate (LiFePO4), discusses phase transformation kinetics in powder samples, and provides methodological recommendations. LiFePO4 is the second most popular positive electrode material in the global lithium battery industry, but the use of Raman spectroscopy for its structural characterization is hampered by the laser‐induced degradation. The statistical/big‐data approach to Raman spectra measurements is utilized to revise the problem and suggest a simple model of laser‐induced phase transformations in powder LiFePO4. The results are proposed to be used for better understanding of the physics and chemistry of other processes taking place in electrochemical cells, namely, lithiation/delithiation and thermal stability/safety studies. Simple recommendations for nondestructive LiFePO4 characterization by Raman spectroscopy are formulated.
关键词： lithium iron phosphate,nondamaging characterization,statistical Raman spectroscopy,lithium batteries,statistical Raman microscopy
更新于2025-09-12 10:27:22
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Facile synthesis of heteroatom doped and undoped graphene quantum dots as active materials for reversible lithium and sodium ions storage
摘要： Zero-dimensional graphene quantum dots have attractive properties but the synthesis of graphene quantum dots in a simple and scalable technique is tedious, which limits its utilization in different energy storage application. In this study, we present a simple and scalable approach to produce graphene quantum dots and heteroatom doped graphene quantum dots using chemical vapor deposition technique. Graphene quantum dots are prepared using alloy-based catalyst and methane as a carbon source. Boron-doped and nitrogen-doped graphene quantum dots are prepared at low temperature using graphite oxide without the use of dialysis bag. Here, the electrochemical lithium and sodium ion storage properties of doped and undoped graphene quantum dots are studied without being used as a supporting material for the performance enhancement as reported in previous reports. Boron doped GQD (B-GQD) exhibits a high specific capacity of 1097 mAh g?1 at a specific current of 50 mA g?1 for lithium and sodium ion batteries respectively. B-GQD exhibits high volumetric energy density of 537 Ah L?1 and 214 Ah L?1 with an average voltage of 0.43 V and 0.57 respectively for lithium ion and sodium ion batteries. Also, the cells observe a satisfactory cyclic performance for 500 cycles with good capacity retention. Detailed investigations show that the edge defects present in GQD and doped GQDs help to enhance the electrochemical storage performance of lithium and sodium ions.
关键词： Doped,Lithium ion battery,Quantum dots,Sodium ion battery,Anode material
更新于2025-09-12 10:27:22
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Periodic Poling with Short Period for Thin Film Lithium Niobate Waveguides
摘要： Lithium niobate (LN) is a favourable material for many applications, especially in integrated optics, due to its excellent electro-optic, acousto-optic, and nonlinear optic properties. One promising application of LN is second-harmonic generation (SHG). For enhancing the efficiency of SHG, phase matching between the interacting waves is needed, which is often realized by employing quasi-phase matching (QPM). QPM is typically realized by periodic poling of LN, i.e. the periodic flipping of the crystal orientation. The needed period is determined by the wavelengths as well as by the wave vectors of the fundamental- and the second-harmonic waves (FW and SH, respectively). For the case of backward SHG with a fundamental wavelength of 1.55 μm, where the SH wave travels in the opposite direction to the FW, typically sub-micrometer periods of the poled LN are required. Here, we demonstrate the realization of short-period QPM structures in LN-on-insulator (LNOI) thin-film substrates with a thickness of 600 nm. We aim to fabricate periodically poled LNOI (PPLNOI) waveguides with a periodicity as small as 1 μm, facilitating efficient nonlinear interaction due to the strong mode confinement.
关键词： periodic poling,second-harmonic generation,integrated optics,Lithium niobate,quasi-phase matching
更新于2025-09-12 10:27:22
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Second-Harmonic Generation in Lithium Niobate Metasurfaces
摘要： Lithium niobate (LN), a birefringent crystal, is an attractive material for nonlinear photonics due to its wide transparency range and high second-order nonlinearity. Among other applications, it has been used for fabrication of fast optical modulators and nonlinear frequency converters. However, almost all implementations to date were using bulk LN crystals or waveguides. Although isolated Mie-type nanoresonators in lithium niobate have been shown very recently [1], functional metasurfaces based on densely packed arrangements of such nanoresonators have not yet been demonstrated. In order to close this gap, we have designed, fabricated and experimentally investigated a nonlinear metasurface consisting of an array of nanocubes featuring Mie-type resonances.
关键词： metasurfaces,nonlinear photonics,Mie-type resonances,second-harmonic generation,Lithium niobate
更新于2025-09-12 10:27:22