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oe1(光电查) - 科学论文

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出版时间
  • 2019
研究主题
  • Distributed optical fiber sensing
  • Optical frequency domain reflection
  • Polynomial regression algorithm
  • Nonlinear tuning compensation
应用领域
  • Optoelectronic Information Science and Engineering
机构单位
  • Hebei University of Technology
777 条数据
?? 中文（中国） ▾

  • Synthesis, crystal structures, second harmonic generation response and temperature phase transitions of two noncentrosymmetric Cu(II)-hybrid halides compounds: [(R)-C7H16N2][CuX4] (X?= Cl or Br)

    摘要： (R)-(+)-3-aminoquinuclidine was used in the synthesis of [(R)-C7H16N2][CuCl4] (1) and [(R)-C7H16N2][CuBr4] (2), which both contain similar [CuX4]2- anions (X = Cl or Br). The structures of the two compounds were determined using single-crystal X-ray diffraction. The use of enantiomerically pure sources of (R)-C7H14N2 forces crystallographic noncentrosymmetry. These materials crystallize in the chiral space group P212121 (No. 19), which exhibits the enantiomorphic crystal class 222 (D2). In the molecular arrangement, the [CuX4]2- anions are linked to the organic cations through N-H...X and C-H...X hydrogen bonds to form cation-anion-cation molecular units, which are held together by means of offset face-to-face interactions giving a three-dimensional network. Thermal stability of the crystals was ascertained by TG measurement. Compounds (1) and (2) display several phases transition with higher transition temperature at T = 100°C. The Kurtz and Perry powder method using Nd:YAG laser shows that their second harmonic generation (SHG) efficiencies are about 0.81 and 0.82 times as large as that of KH2PO4 (KDP), respectively. Such a chiral hybrid metal halides skeleton could provide a new platform for future engineering in the areas including information storage, light modulators and optoelectronic functionalities.

    关键词： nonlinear optics,second harmonic generation,crystal structure,chiral hybrid halide,phase transitions

    更新于2025-09-23 15:23:52

  • Conditions for Parametric and Free-Carrier Oscillation in Silicon Ring Cavities

    摘要： We model optical parametric oscillation in ring cavities with two-photon absorption, focusing on silicon at 1.55 μm. Oscillation is possible if free-carrier absorption can be mitigated; this can be achieved using carrier sweep-out in a reverse-biased p-i-n junction to reduce the carrier lifetime. By varying the pump power, detuning, and reverse-bias voltage, it is possible to generate frequency combs in cavities with both normal and anomalous dispersion at a wide range of wavelengths including 1.55 μm. Furthermore, a free-carrier self-pulsing instability leads to rich dynamics when the carrier lifetime is sufficiently long.

    关键词： nonlinear optics,Frequency comb,silicon photonics

    更新于2025-09-23 15:23:52

  • Dechirping Compression Method for Nonlinear Frequency Modulation Waveforms

    摘要： This letter proposes a novel dechirp processing method for wideband nonlinear frequency modulation (NLFM) waveform which enables low sampling rate of data. As we know, NLFM waveform can easily realize optimal shape of power spectral density which helps to achieve better pulse compression result with low range sidelobes without signal-to-noise ratio degradation caused by weighting as we usually do for LFM waveforms. In the approach, hamming window is adopted in the generation of the NLFM waveform for better balance on the low range sidelobes and a relative small bandwidth. In dechirp operation, the NLFM radar echoes are mixed with a local reference LFM signal, and thus narrowband signals are resulted and only low sampling rate is needed. The dechirped NLFM signals are then up-sampled and inverse dechirped by software and ?nally matched ?ltering is conducted to complete pulse compression. Both numerically simulated data and real radar data are processed to verify the effectiveness of the proposed method.

    关键词： nonlinear frequency modulation (NLFM),sampling rate,pulse compression,Dechirp processing

    更新于2025-09-23 15:23:52

  • Limitations of graphene nanocoated optical tapers for high-power nonlinear applications

    摘要： In this letter, we investigate the limitations of graphene as a saturable absorber for high-power nonlinear optical applications. The response of graphene nanocoated optical tapers against the average optical power injected is tested. We point out that the power handled by such components is limited and their nonlinear properties are strongly and permanently modified when exposed to high optical power. The origin of the degradation of the components is discussed.

    关键词： nonlinear optics,mode-locking,fiber laser,Graphene,optical tapers

    更新于2025-09-23 15:23:52

  • Generalization of optical solitons with dual dispersion in the presence of Kerr and quadratic-cubic law nonlinearities

    摘要： In this work, nonlinear Schr?dinger’s equation along with group velocity dispersion and spatio-temporal dispersion is considered in (n + 1) dimensions with Kerr and quadratic-cubic law nonlinearities which expose the propagation of light pulses in fiber optics. Dark, singular and periodic singular optical solitons in (n + 1) dimensions are retrieved and generalized through versatile modified simple equation method. The constraint conditions that righteously guarantee the perseverance of these soliton solutions are obtained as an outgrowth. The results presented in this paper are new and generalized which are already available in the literature.

    关键词： constraints,(n + 1)-dimensional nonlinear Schr?dinger’s equation,modified simple equation method

    更新于2025-09-23 15:23:52

  • Averaged nonlinear equations for multimode fibers valid in all regimes of random linear coupling

    摘要： We develop averaged equations to model nonlinear propagation in multimode fibers that are valid in all regimes of random, linear, intermodal coupling. The propagation equations apply to the three existing regimes of linear coupling – the two previously studied all-mode (strong) and mode-group (weak) couplings and the new intermediate coupling regime. The equations are therefore general and can describe nonlinear propagation for all types of intermodal linear coupling that can exist between modes in a fiber supporting multiple spatial modes. Numerical simulations are performed to validate the new averaged propagation equations in the nonlinear regime.

    关键词： Space-division multiplexing,Nonlinear optics,Multimode fibers

    更新于2025-09-23 15:23:52

  • One-drop Self-assembly and Size Control of Organic Nonlinear Optical Crystal DSNS Nanowires

    摘要： In this study, we demonstrate a one-drop self-assembly method for fabricating nanowires (NWs) of organic second-order nonlinear optical (NLO) material, 4-N, N-dimethylamino-4'-N'-methyl- stilbazolium 2-naphthalenesulfonate (DSNS). By controlling the parameters of the self-assembly process, we successfully controlled the length of DSNS from a few micrometers to millimeters. The obtained NWs have very high surface quality with surface roughness <150 pm, which is highly beneficial for fabricating integrated optical devices. DSNS NW has the same triclinic crystal structure as that of bulk crystal and exhibits excellent second-order NLO and fluorescent properties, which could provide wide opportunities for on-chip optoelectronic devices and integrated photonic systems. Furthermore, the one-drop self-assembly method only requires reagents in microgram quantities, and thus this method is extremely environment-friendly.

    关键词： one-drop self-assembly,organic nanowire,size control,nonlinear optical material

    更新于2025-09-23 15:23:52

  • Exceptional Two-Photon Absorption in Alkynylruthenium-Gold Nanoparticle Hybrids

    摘要： Ruthenium alkynyl “star” complexes with tri(2-thienyl)-, tris(1,2,3-triazolyl)-, or triphenyl-benzene cores stabilize gold nanoparticles (AuNPs). Cyclic voltammetry, transmission electron microscopy, molecular modeling, dynamic light scattering, X-ray photoelectron spectroscopy, and energy-dispersive X-ray spectroscopy studies are consistent with ca. 5 trithienyl- or triazolyl-benzene-cored star complexes decorating the exterior of each AuNP. The ca. 2.5 nm diameter (by TEM) trithienylbenzene-cored gold nanoparticle hybrids are significantly less absorbing than classical Brust nanoparticles stabilized by 1-dodecanethiol; with femtosecond pulsed radiation, they exhibit exceptionally strong saturable absorption and two-photon absorption across the visible range and into the NIR region (3,000,000 GM at 500 nm, 46,000 GM at 750 nm; 1 GM = 10-50 cm4 s photon-1).

    关键词： Gold nanoparticles,nonlinear optics,inorganic materials,metal alkynyl complexes,organometallics.

    更新于2025-09-23 15:23:52

  • Analysis of Nonlinear Dynamics of a Quadratic Boost Converter Used for Maximum Power Point Tracking in a Grid-Interlinked PV System

    摘要： In this paper, the nonlinear dynamics of a PV-fed high-voltage-gain single-switch quadratic boost converter loaded by a grid-interlinked DC-AC inverter is explored in its parameter space. The control of the input port of the converter is designed using a resistive control approach ensuring stability at the slow time-scale. However, time-domain simulations, performed on a full-order circuit-level switched model implemented in PSIM c software, show that at relatively high irradiance levels, the system may exhibit undesired subharmonic instabilities at the fast time-scale. A model of the system is derived, and a closed-form expression is used for locating the subharmonic instability boundary in terms of parameters of different nature. The theoretical results are in remarkable agreement with the numerical simulations and experimental measurements using a laboratory prototype. The modeling method proposed and the results obtained can help in guiding the design of power conditioning converters for solar PV systems, as well as other similar structures for energy conversion systems.

    关键词： subharmonic oscillations,DC-DC converters,maximum power point tracking (MPPT),nonlinear dynamics,photovoltaic (PV),quadratic boost

    更新于2025-09-23 15:23:52

  • Enhanced Second Harmonic Generation from Ferroelectric HfO <sub/>2</sub> -Based Hybrid Metasurfaces

    摘要： Integrated nonlinear metasurfaces leading to high-efficiency optical second harmonic generation (SHG) are highly desirable for optical sensing, imaging, and quantum photonic systems. Compared to traditional metal-only metasurfaces, their hybrid counterparts, where a non-centrosymmetric nonlinear photonic material is incorporated in the near field of a metasurface, they can significantly boost SHG efficiency. However, it is difficult to integrate such devices on-chip due to material incompatibilities, thickness scaling challenges and the narrow band gaps of nonlinear optical materials. Here, we demonstrate significantly enhanced SHG in on-chip integrated metasurfaces by using nanometer thin films of ferroelectric Y:HfO2. This material has the merit of CMOS compatibility, ultra-violet transparency up to 250 nm and significant scalability down to sub 10 nm when deposited on silicon. We observe a twenty times magnitude enhancement of the SHG intensity from the hybrid metasurface compared to a bare ferroelectric HfO2 thin film. Moreover, a 3-fold SHG enhancement is observed from the hybrid metasurface compared to a control structure using non-ferroelectric HfO2, demonstrating a major contribution to the SHG signal from ferroelectric Y:HfO2. The effective second-order nonlinear optical coefficient χ(2) of Y:HfO2 is determined to be 6.0 ± 0.5 pm/V, which is comparable to other complex nonlinear photonic oxide materials. Our work provides a general pathway to build an efficient on-chip nanophotonic nonlinear light source for SHG using ferroelectric HfO2 thin films.

    关键词： second harmonic generation (SHG),nonlinear photonics,metasurface,plasmonics,ferroelectric Y:HfO2

    更新于2025-09-23 15:23:52