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oe1(光电查) - 科学论文

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出版时间
  • 2019
  • 2018
研究主题
  • microwave photonics
  • interdigital resonator
  • microwave gas sensor
  • PSE-coated
  • microwave photonic mixer
  • analog optical signal processing
  • phase shift
  • photonic array antenna
  • gain
  • integrate
应用领域
  • Optoelectronic Information Science and Engineering
机构单位
  • Inner Mongolia University
  • Jinan University
  • King Mongkut’s University of Technology North Bangkok
  • Beijing University of Posts and Telecommunications
  • Wroclaw University of Technology
  • Rajamangala University of Technology Suvarnabhumi
  • Southern University of Science and Technology
  • Charles Darwin University
  • University of Ottawa
  • University of Kent
508 条数据
?? 中文(中国)
  • Large-Dynamic Frequency Response Measurement for Broadband Electro-Optic Phase Modulators

    摘要: A novel method for characterizing the frequency responses of broadband electro-optic phase modulators (PMs) by employing stimulated Brillouin scattering (SBS) is proposed and experimentally demonstrated. In the proposed method, the SBS amplifies the +1st-order sideband and attenuates the -1st-order sideband of the phase-modulated signal from a PM under test. Thereby, the phase-modulated signal is converted into an optical single-sideband (OSSB) modulation signal. After square-law photodetection, the overall frequency responses are obtained. Removing the frequency responses of the SBS gain and the photodetector (PD) from the overall responses, the responses of the PM are thus achieved. Benefitting from the amplification of the SBS, the proposed method possesses a large dynamic range. Sub-Hz resolution and broadband measurement range are also achievable. A commercial broadband PM is experimentally characterized from 10 MHz to 50 GHz with a resolution of 5 MHz. According to the amplification of the SBS, the dynamic range is enhanced by 17.74 dB. The measurement result is verified by the conventional method utilizing optical spectrum analysis.

    关键词: stimulated Brillouin scattering,Electrooptic modulation,Phase modulation,microwave photonics,optical variables measurement

    更新于2025-11-28 14:24:03

  • Active ring resonance cavity assisted single-mode all-optical microwave oscillator

    摘要: A pure optical microwave oscillator with single mode oscillation is proposed and demonstrated. This system has no any electrical microwave devices as well as electro-optic (E/O) and opto-electronic (O/E) conversion. The oscillation frequency is chosen by Brillouin-selective sideband amplification, and the optical envelope detection and feedback modulation are implemented by a semiconductor optical amplifier (SOA). As a high-Q tunable optical comb filter, an active ring resonance cavity (ARRC) is employed to select one oscillation mode within the Brillouin gain region, and consequently a single mode oscillation signal can be generated. In the experiment, a single mode photonic microwave signal with frequency of 10.83 GHz and side-mode suppression ratio of 48 dB is obtained. The measured phase noise is ?88 dBc/Hz@10 kHz. In addition, the tunability is also demonstrated by adjusting the wavelength of the light source.

    关键词: Microwave photonics,SBS,All-optical microwave oscillator

    更新于2025-11-28 14:23:57

  • 100?GHz free spectral range-tunable multi-wavelength fiber laser using single–multi–single mode fiber interferometer

    摘要: Six single–multi–single (SMS) mode fiber-based Mach–Zehnder Interferometers (MZI) with different spooling radii are demonstrated as spatial mode filtering elements for multi-wavelength laser generation. Free spectral range (FSR) tuning of the multi-wavelength output generated is realized by alternating between the six MZIs, which have different macro-bending losses. Additional FSR tuning is also realized by changing the spooling radius of the two-mode step index fiber section within the MZI setups from 80 mm to 30 mm, giving an FSR tuning range of 0.89–0.99 nm. All generated multi-wavelength outputs show high stability over a test period of 100 min. The proposed multi-wavelength lasers are highly suitable for various microwave photonics applications the field of such as microwave signal source generation and microwave photonic filtering.

    关键词: free spectral range tuning,Mach–Zehnder Interferometer,microwave photonics,multi-wavelength fiber laser

    更新于2025-11-28 14:23:57

  • Eu-doped layered yttrium hydroxides sensitized by series of benzenedicarboxylate and sulphobenzoate anions

    摘要: A number of Eu-doped layered yttrium hydroxides intercalated with various benzenedicarboxylate (phthalate, isophthalate and terephthalate) and sulphobenzoate (2-, 3- and 4-sulphobenzoate) anions was obtained using hydrothermal microwave (HTMW) treatment. For the first time, phthalate, isophthalate and sulphobenzoate anions were intercalated into layered rare-earth hydroxides (LRHs). Two approaches to the synthesis of intercalated layered yttrium hydroxides were used: ion exchange reactions and homogeneous hydrolysis of rare-earth cations in the presence of the intercalated anion. Ion-exchange reactions between layered rare-earth hydroxides and a series of benzenedicarboxylic and sulphobenzoic acid salts were performed under conditions of HTMW treatment, which significantly increased the rate of intercalation. The structure of the first representative of layered rare-earth hydroxides intercalated with sulphobenzoate-type anions, namely layered yttrium hydroxide intercalated with 4-sulphobenzoate of composition Y3(OH)7(C7H4O5S)·H2O, was solved. Intercalation of benzenedicarboxylate and sulphobenzoate anions into Eu-doped layered yttrium hydroxides led to a substantial sensitization of Eu3+ luminescence. The local symmetry of Eu3+ was greatly decreased by intercalation of benzenedicarboxylate and sulphobenzoate anions.

    关键词: Layered rare-earth hydroxides,anion exchange,LRH,hydrothermal microwave treatment,luminescence,hybrid materials

    更新于2025-11-21 11:20:42

  • Microwave-Assisted Synthesis of Quasi-Pyramidal CuInS <sub/>2</sub> -ZnS Nanocrystals for Enhanced Near-Infrared Targeted Fluorescent Imaging of Subcutaneous Melanoma

    摘要: Near-infrared (NIR) fluorescent CuInS2–ZnS nanocrystals (CIZS NCs) are synthesized via an ultra-fast, non-injection microwave (MW)-assisted nanoalloying process at 230 oC within 5 min using 1-dodecanethiol (DDT) as both the sulfur source and solvent under solvothermal (ST) condition. The structural and surface analyses reveal that DDT-functionalized CIZS NCs exhibit quasi-pyramids of tetragonal-phase with well-defined facets. The DDT-functionalized CIZS NCs present a photoluminescence quantum yield (PLQY) of 76% and a long-lived fluorescence lifetime of ≈0.6 μs in organic-phase. Subsequently, DDT-functionalized CIZS NCs are phase-transferred via ligand-exchange using 11-mercaptoundecanoic acid (MUA) into water-soluble MUA–CIZS NCs that exhibit a substantial PLQY of 55%. In addition, the NIR-fluorescent MUA-functionalized CIZS NCs in conjugation with folic acid (FA), as a tumor-targeting ligand, demonstrates enhanced tumor-targeted imaging ability. The FA–MUA–CIZS NC conjugates exhibit a cell viability of ≈75% even at the highest concentration of 1 mg mL–1 and a labeling efficiency of 95.4%. The in vivo imaging results corroborate that FA–MUA–CIZS NCs conjugates are actively targeted to folate receptor-positive B16F10 tumor-bearing C57BL/6 mice in 2 h. The histopathological and hematological studies confirm no significant changes in tissue architecture and blood biochemical parameters. The confocal microscopy studies reveal deep penetration and uniform distribution of FA–MUA–CIZS NCs conjugates in subcutaneous melanoma.

    关键词: CuInS2–ZnS nanocrystals,nano-bioprobe,nanoalloying approach,targeted bioimaging,microwave-solvothermal method

    更新于2025-11-21 11:08:12

  • Photoluminescence enhancement <i>via</i> microwave irradiation of carbon quantum dots derived from solvothermal synthesis of <scp>l</scp> -arginine

    摘要: Photoluminescence enhancement of carbon quantum dots was achieved via solvothermal synthesis followed by microwave irradiation. Nitrogen and phosphorous doped carbon quantum dots were prepared by solvothermal heating of L-arginine with phosphoric acid for 12 hours followed by microwave irradiation for 3 minutes. The photoluminescence enhancement was nearly two fold after microwave irradiation. The morphology, structure, and surface properties were the same for the solvothermal (CQDs-S) as well as after microwave (CQDs-M) irradiation. Thus, the enhancement is attributed to the decrease of surface defects within CQDs, which led to a decrease in the non-radiative transitions. The CQDs were quenched selectively by Fe3+ ions. The quenching led to the fabrication of the fluorescence probe for ferric ion determination. The CQDs-M had a low detection limit of 4.0 nM, while CQDs-S had a limit of 50 nM. This study gives a tool for enhancing photoluminescence quantum yields, which is highly desired for biosensing and bioimaging applications.

    关键词: Photoluminescence enhancement,Fluorescence probe,Solvothermal synthesis,Ferric ion determination,Microwave irradiation,Carbon quantum dots

    更新于2025-11-19 16:56:42

  • Microwave-assisted synthesis of graphene quantum dots and nitrogen-doped graphene quantum dots: Raman characterization and their optical properties

    摘要: In this report we will present completely new results on the improvement of the graphene quantum dots (GQDs) and nitrogen-doped graphene quantum dots (N-GQD) production method, using the microwave with different power levels and durations, from citric acid and urea. This is a new and unprecedented method of fabrication. The use of microwave has allowed ultra-fast fabrication of GQDs and nitrogen doped GQDs. These GQDs had their characteristics identi?ed by Raman scattering spectra for the characteristic C–C graphene vibration mode (G-peak) and defects of GQDs (D-peak). The absorption spectra of GQDs samples were fabricated under different conditions, with the expectation of different sizes, to be compared and analyzed. These absorption spectra were also compared with those of the N-GQD produced under the same conditions. The absorption mechanism of GQDs and N-GQD will be presented in detail. Measurements of the photoluminescence (PL) spectra in GQDs and N-GQD have also been recorded and analyzed. The ?uorescence mechanism will be presented, explained, and compared with other international publications of other authors. Some of the TEM and HR-TEM images of these two samples were also presented to con?rm the shape, size and in-plane spacing lattice of the GQD structure.

    关键词: graphene quantum dots (GQDs),PL spectra,nitrogen-doped graphene quantum dots (N-GQD),microwave,Raman spectra,absorption spectra

    更新于2025-11-19 16:56:42

  • Visible light-driven photoelectrocatalytic degradation of Acid Yellow 17 using Sn3O4 flower-like thin films supported on Ti substrate (Sn3O4/TiO2/Ti)

    摘要: This article reports a new method for preparing mixed valence tin oxide (Sn3O4) flower-like nanostructures using a microwave-assisted route. Thin-film Sn3O4/TiO2/Ti electrodes demonstrated highly efficient visible light driven photocatalytic degradation of monoazo acid yellow 17 (AY17) dye, reaching 95% color removal after 60 min at pH 2. Moreover, under low bias potential (0.5 V), the photoelectrocatalytic efficiency increased to 97% color removal and 83% removal of total organic carbon at a kinetic rate almost 3 times higher than in photocatalysis. Liquid chromatography mass spectrometry was used to identify intermediate formation, and oxidation performance was proposed for photocatalytic and photoelectrocatalytic degradation with no organics identified after 120 min of treatment. The results indicate that Sn3O4/TiO2/Ti photoelectrodes offer a simple, green method for wastewater treatment employing visible light source.

    关键词: Dye degradation,Photoelectrocatalysis,Microwave-assisted hydrothermal synthesis,Sn3O4,Visible-light photocatalysis

    更新于2025-11-19 16:56:35

  • One-step Aqueous Synthesis of Zn-based Quantum Dots as Potential Generators of Reactive Oxygen Species

    摘要: The actual incorporation of dopant species into the ZnS Quantum Dots (QDs) host lattice will induce structural defects evidenced by a red shift in the corresponding exciton. The doping should create new intermediate energetic levels between the valence and conduction bands of the ZnS and affect the electron-hole recombination. These trap states would favour the energy transfer processes involved with the generation of cytotoxic radicals, so-called Reactive Oxygen Species, opening the possibility to apply these nanomaterials in cancer research. Any synthesis approach should consider the direct formation of the QDs in biocompatible medium. Accordingly, the present work addresses the microwave-assisted aqueous synthesis of pure and doped ZnS QDs. As-synthesized quantum dots were fully characterized on a structural, morphological and optical viewpoint. UV-Vis analyzes evidenced the excitonic peaks at approximately 310 nm, 314 nm and 315 nm for ZnS, Cu-ZnS and Mn-ZnS, respectively, Cu/Zn and Mn/Zn molar ratio was 0.05%. This indicates the actual incorporation of the dopant species into the host lattice. In addition, the Photoluminescence spectrum of non-doped ZnS nanoparticles showed a high emission peak that was red shifted when Mn2+ or Cu2+ were added during the synthesis process. The main emission peak of non-doped ZnS, Cu-doped ZnS and Mn-doped ZnS were observed at 438 nm, 487 nm and 521 nm, respectively. Forthcoming work will address the capacity of pure and Cu-, Mn-ZnS quantum dots to generate cytotoxic Reactive Oxygen Species for cancer treatment applications.

    关键词: Cancer research,ZnS Quantum Dots,Doping,Microwave-assisted synthesis,Reactive Oxygen Species

    更新于2025-11-19 16:46:39

  • In Situ Microwave-Assisted Fabrication of Hierarchically Arranged Metal Sulfide Counter Electrodes to Boost Stability and Efficiency of Quantum Dot-Sensitized Solar Cells

    摘要: This study describes preparation of metal sulfide counter electrodes (CEs) through one-pot microwave-assisted route to improve power conversion efficiency (PCE) of quantum dot-sensitized solar cells at a lower cost. The CuS nanorods, Ni0.96S nanoparticles, and PbS nanocubes are synthesized and deposited in situ on fluorine-doped tin oxide substrate to serve as CEs without further post-treatment. Effects of several reaction parameters including sulfur precursor (Na2S, C2H5NS, CH4N2S), Cu concentration, reaction time, and choice of cation (Cu, Ni, Pb) on the CEs morphology, electrochemical characteristics, and PCE are studied. Furthermore, nanostructure formation and thin film growth are studied and correlated with PCE, from which morphology- and composition-performance relationships can be inferred. Hierarchically assembled nanorod CuS CEs exhibit higher electrochemical stability in the S2–/Sn2– redox reaction. Together with the efficient charge transfer and higher diffusion coefficient of polysulfide redox at the electrode/electrolyte interface, deduced from electrochemical impedance spectroscopy and Tafel analyses, a PCE of 8.32% is achieved for the CuS CE. The enhanced photovoltaic performance is ascribed to the 1D CuS nanorods forming a diffusive structure which decreases charge transfer impedance and facilitates regeneration of polysulfide redox leading to a higher short-circuit current density and fill factor.

    关键词: In situ deposition,quantum dot-sensitized solar cells,counter electrode,CuS,microwave-assisted synthesis

    更新于2025-11-14 17:04:02