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oe1(光电查) - 科学论文

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出版时间
  • 2018
研究主题
  • Signal-to-Noise Ratio (SNR)
  • Infinite Gain Multiple Feedback (IGMF)
  • Visible Light Communications (VLC)
  • LED
  • Trans-Impedance Amplifier (TIA)
应用领域
  • Optoelectronic Information Science and Engineering
机构单位
  • University of Northumbria
  • University of Huddersfield
233 条数据
?? 中文（中国） ▾

  • [IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Research on Adaptive Optimal Shaping Gain Selection MethodBased on Huffman Coding

    摘要： In this paper, an adaptive optimal shaping gain selection method based on huffman coding is proposed. By non-uniform mapping, the input signal satisfies the optimal (secondary) distribution under different SNR, that is, the input signal is infinitely close to Maxwell Boltzmann distribution, so that the channel capacity wirelessly approaches the Shannon limit. The method not only improves the transmission performance of the system, increases the shaping gain, but also saves the algorithm complexity and system cost, and realizes the optimal distribution of the optimal (secondary)input signals under different SNR, thereby infinitely approaching the high-speed transmission of the channel capacity.

    关键词： adaptive,Shannon limit,shaping gain,probabilistic shaping

    更新于2025-09-16 10:30:52

  • [IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Analysis on Gain And Noise Figure of Direct Modulation RoF Link

    摘要： The equivalent circuit model of direct modulation RoF link is introduced. Based on this model, the mathematical expressions of link gain and noise figure are both derived. The factors affecting the transmission characteristics, especially the parasitic parameters of lasers and detectors, are further analyzed. Finally, a general method to improve link gain and reduce noise figure is given.

    关键词： gain,direct modulation,RoF,noise figure

    更新于2025-09-16 10:30:52

  • Simulation of optical fiber amplifier gain using equivalent short fibers

    摘要： Electromagnetic wave propagation in optical fiber amplifiers obeys Maxwell equations. Using coupled mode theory, the full Maxwell system within an optical fiber amplifier is reduced to a simpler model. The simpler model is made more efficient through a new scale model, referred to as an equivalent short fiber, which captures some of the essential characteristics of a longer fiber. The equivalent short fiber can be viewed as a fiber made using artificial (unphysical) material properties that in some sense compensates for its reduced length. The computations can be accelerated by a factor approximately equal to the ratio of the original length to the reduced length of the equivalent fiber. Computations using models of two commercially available fibers – one doped with ytterbium, and the other with thulium – show the practical utility of the concept. Extensive numerical studies are conducted to assess when the equivalent short fiber model is useful and when it is not.

    关键词： Scale model,Ytterbium,Thulium,Laser gain,Fiber amplifier

    更新于2025-09-16 10:30:52

  • [IEEE 2019 International Seminar on Intelligent Technology and Its Applications (ISITIA) - Surabaya, Indonesia (2019.8.28-2019.8.29)] 2019 International Seminar on Intelligent Technology and Its Applications (ISITIA) - Application of High Gain Zeta Converter For Photovoltaic System

    摘要： Photovoltaics are generally used to convert solar energy into electrical energy. If the number of photovoltaic module are limited, then the output voltage will be small. In order to connect the inverter to the grid directly without any transformer devices, it requires extra high gain boost converter. In practice, conventional boost converter only able to increase the input voltage about 4 times. Therefore, this research will implement and analyze the performances of integrated quadratic-boost-zeta high gain DC-DC converter for photovoltaic application. The advantage of this converter is having a high ratio voltage conversion with a small duty cycle and requires few components. From the experiment, this converter can convert input voltage from 18 V to 330 V on duty cycle of 65,92%.

    关键词： photovoltaic,quadratic boost zeta converter,coupled inductor,high gain

    更新于2025-09-16 10:30:52

  • Tunable random fiber laser with half-open-cavity configuration

    摘要： A half-open-cavity random ?ber laser with a simple structure and adjustable wavelength has been proposed and demonstrated, which uses stimulated Brillouin scattering and erbium-doped ?ber to provide hybrid gain and Rayleigh scattering as random distribution feedback. With the pump power of the 980 nm lasers increasing, the highest 7th-order Stokes laser output can be obtained, when the Brillouin pump wavelength and power are ?xed at 1560 nm and 7.4 dB m respectively. Furthermore, the output wavelength of the Brillouin random laser can be tunable in the range of from 1529 nm to 1588 nm with the Stokes order number remained 7, indicating that the random ?ber laser has a wavelength adjustable range of 36 nm.

    关键词： Hybrid gain,Tunable wavelength,Random ?ber laser

    更新于2025-09-16 10:30:52

  • Effects of the gamma-ray irradiation on the structure, spectral and laser damage threshold of Nd:GSAG crystal

    摘要： Nd:GSAG crystal was irradiated by 60Co gamma-ray with the irradiation doses of 0, 2, 10 and 20 Mrad, respectively, to investigate its radiation resistant properties. XRD and Raman spectra characterization results indicate that the crystal structure was unchanged by the irradiation. Therefore, the color change of the crystal caused by irradiation could be attributed to the formation of the color centers inside the crystal. Only slightly decreased of the transmittance and laser damage threshold of the crystal with the irradiation dose of 20 Mrad indicate the crystal is of excellent radiation resistant ability. All the results suggest that Nd:GSAG crystal can be considered as a potential laser gain medium for being used in radiant environment.

    关键词： Gamma-ray,Damage threshold,Nd:GSAG,Laser gain medium,Radiation resistant

    更新于2025-09-16 10:30:52

  • [IEEE IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Society - Lisbon, Portugal (2019.10.14-2019.10.17)] IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Society - Coupled-Inductor-Based Differential Boost Inverter with Wide Input Voltage Range for Photovoltaic Generation Applications

    摘要： The differential boost inverter has been widely used as a microinverter for the renewable distributed generations as it achieves an ac voltage with amplitude larger than the dc input. However, the unlimited voltage gain of the boost inverter is practically unachievable due to the existence of the parasitic resistance of the input inductor, which narrows the input voltage range and distorts the output voltage waveform as the turn-on duty ratio of the power switches approaches unity. To solve this problem, a novel coupled-inductor-based differential boost inverter is proposed, which uses a two-winding or three-winding coupled inductor to enhanced voltage gain. As a result, the input voltage range of the proposed inverter is significantly widened, facilitating grid-connected applications with a very low dc input voltage, compatible to the outputs of most PV panels. Moreover, the leakage inductance energy of the coupled inductor is recycled with voltages across the power switches clamped to the dc link capacitor by using a lossless diode. A prototype with 30 V dc input, 155 V ac output, nominal power 200 W, was built, which achieves a high voltage-boost, while keeping relatively low voltages stresses on the semiconductor devices.

    关键词： coupled-inductor boost inverter,PV generation application,leakage inductance effect,high voltage gain

    更新于2025-09-16 10:30:52

  • [IEEE 2019 IEEE High Power Diode Lasers and Systems Conference (HPD) - Coventry, United Kingdom (2019.10.9-2019.10.10)] 2019 IEEE High Power Diode Lasers and Systems Conference (HPD) - Simulation of the slow-axis beam properties of broad-area lasers and its use in the development of high-brightness sources

    摘要： The objective of this work is to demonstrate that the slow-axis beam properties of broad-area diode lasers can be predicted by numerical modeling and that the results guide design decisions in the semiconductor laser development. We present a numerical study for 6 different semiconductor laser single emitter designs and compare the computed results to experimental values. The devices differ in width of the contact opening, cavity length, position and depth of an index trench, and facet re?ectivity.

    关键词： Semiconductor Lasers,Index-Guided,Beam Propagation Method,Lasers,Modeling,Gain-Guided,Frequency Domain,Simulation,Thermal Lens,Diode Lasers,Broad-Area

    更新于2025-09-16 10:30:52

  • Emission cross section and optical gain of 1.06mm laser Nd 3+ doped borate glasses

    摘要： In this paper we develop the optical pumping system based on 805 nm laser diode as photo-pumped source. Laser with a wavelength of 1064 nm is used as reference source and passed in a laser glass medium. Laser glass medium was synthesized from chemical compositions of (65-x)B2O3-15Na2O-10PbO-5ZnO-5Li2O-xNd2O3 (with x = 0.05, 0.1, 0.5, 1.0, 2.0 and 4.0). The emission spectra confirms that there are three emission peaks located at 946 nm, 1064 nm and 1350 nm corresponding to 4F3/2→4I9/2, 4F3/2→4I11/2 and 4F3/2→4I13/2 respectively. The emission cross section relatively higher for the 4F3/2→4I11/2 transition shows the compatibility of these glasses for near infra-red laser application. The measurements of optical gain had been carried out by using lock-in amplifier with voltage as output signal. From output voltage converted to optical gain in dB. The glass medium with 1.0 Nd3+ label was obtained the maximum optical gain with incident power 900 mW.

    关键词： Emission Cross Section,Glasses,Optical Gain

    更新于2025-09-16 10:30:52

  • Development of Eu3+ doped boro-tellurite oxyfluoride glass and their Judd-Ofelt analysis for red laser gain medium application

    摘要： This paper investigated the physical, optical, luminescence and radiative properties of Eu3+ doped borotellurite oxyfluoride glass with composition (30-x)TeO2-30B2O3-10ZnF2-30BaO-xEu2O3 where x are 0.05, 0.10, 0.50, 1.00 and 1.50 mol%. The glass samples were fabricated by melt and quenching method. The physical and optical properties were investigated from density, molar volume and refractive index. Meanwhile absorption spectra that show several transitions in the ultraviolet to near infrared region interpret the optical properties of the glass sample. The emission spectra of glass sample were measured under excited ?ex = 394 nm. The highest peak of emission spectra occurs in 1.5 mol% of Eu2O3 due to 5D0→7F2 transition centered at 613 nm. The emission intensity was increased by the addition of Eu2O3 from 0.05 mol% to 1.5 mol%. In addition, Judd-Ofelt (JO) theory was used to define the radiative properties and lasing potential of the glass sample. The value of JO parameter ?2, ?4, ?6 was calculated and compared with literatures. Other radiative properties including experimental (fexp) and calculated (fcal) oscillator strengths, stimulated emission cross-sections (σ), radiative transition probability (AR), experimental and calculated branching ratios (?R) of glass sample were determined and discussed in term of red laser gain medium application.

    关键词： Oxyfluoride glass,Europium,Gain medium

    更新于2025-09-16 10:30:52