- 标题
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Design and development of a novel level transmitter utilizing lithium niobate (LiNbO3) Mach-Zehnder modulator for hazardous regions
摘要： In the proposed work, a very low-cost transducer and a novel photonic based transmission technique have developed for liquid level measurement. Two copper parallel plates are used to measure the liquid level in the sensing tube. For transmission of the measured quantity to the remote location, electrical (1–5 V DC), as well as optical technique, has been used. A lithium niobate (LiNbO3) based Mach Zehnder interferometer has been used for the optical transmission. In the proposed method 40GHz, Photline made MXAN-LN-40 light intensity Mach-Zehnder modulator was used. The optical output was analyzed with the help of optical spectrum analyzer (MS9710B) as well as optical meter. Optical transmission was not affected by EMI interference and very advantageous in the inflammable regions. With the help of the proposed method, the sensitivity of 7.02 pF/cm. from the sensor and ?0.236 dBm/cm. from the modulator were achieved. The output of the sensor, signal conditioning, and optically transmitted data has been analyzed experimentally.
关键词： Level transmitter,Optical intensity modulator,Optical spectrum analyzer (OSA),Level sensor,Optical power meter
更新于2025-09-23 15:23:52
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Spin-Hamiltonian parameters and tetragonal distortion for the (WO6)7? octahedral centers in the WO3-doped Zn(PO4)2 ZnO nanopowders
摘要： The spin-Hamiltonian parameters (g factors g//, g⊥ and hyperfine structure constants A//, A⊥) of the tetragonal (WO6)7? octahedral center in the WO3-doped Zn3(PO4)2ZnO nanopowders are investigated from the high-order perturbation formulas resting on the two-mechanism (crystal-field and charge-transfer mechanisms) model with a suitable assignment of the absorption band at about 14,370 cm?1. The calculated results are in keeping with the experimental values. The tetragonal distortion of the (WO6)7? octahedral center is also achieved on the basis of the calculation. The outcomes are discussed.
关键词： W5+,Optical spectrum,Zn3(PO4)2ZnO,Crystal-and ligand-field theory,Spin-Hamiltonian parameters
更新于2025-09-23 15:22:29
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High sensitivity sensing system theoretical research base on waveguide-nano DBRs one dimensional photonic crystal microstructure
摘要： In this paper, we propose a novel wavelength modulation system dedicated to improve the performance of the integrated silicon microsensor. This system includes light source, waveguide, distributed Bragg reflectors (DBRs) and optical spectrum analyzer. Here, the silicon waveguide and two nano DBRs were designed to be one dimensional photonic crystal structure, which can implement wider modulation range in the photonic band gap. The rigorous coupled wave analysis (RCWA) method was used to quantitatively calculate transmissivity of each wavelength photon, and then spectral data in different displacement were obtained. By analyzing the defect modes in the spectrum, typical performance indicators of this modulation system are demonstrated as follows: The wavelength defect mode can be modulated from 1.2 μm to 2.7 μm, corresponding displacement is from 0 to 1.5 μm; System sensitivity is up to 1.23-1.41, linearity ranges from 0.99 to 0.9999 for order 1 defect mode; The minimum peak transmittance of defect mode is greater than 0.68 based on 1 pm wavelength calculated step. Compared with the same type of system reported, the performance indicators have obvious advantages, and it is expected to directly improve the sensor performance by combining with the existing micro-mechanical structure.
关键词： Optical instruments,Optical spectrum analysis,Optical systems,Optical design of instruments
更新于2025-09-23 15:19:57
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[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) - Optical Spectrum Measurement and Analysis for Flexible WDM System Using Faster R-CNN-based Object Detection
摘要： An optical spectrum measurement and analysis method using faster R-CNN-based object detection technique is proposed. This method can simultaneously analyze OSNR, bandwidth, and center wavelength of FWDM system. The average accuracy reaches 98.6%.
关键词： Optical performance monitoring,Object detection,Optical spectrum analysis
更新于2025-09-16 10:30:52
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Laser modification of high-pressure high-temperature nanodiamonds
摘要： Micro-thin semitransparent films of purified high pressure high temperature nanodiamonds were produced on a glass substrate. A focused 632.8 nm He-Ne laser irradiation is shown to cause an emission of light in the green region of the optical spectrum accompanied with laser-induced blackening of the obtained films. Possible mechanisms of the observed phenomenon are discussed.
关键词： optical spectrum,laser modification,nanodiamonds,sp2-carbon,sp3-carbon,high-pressure high-temperature
更新于2025-09-12 10:27:22
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Nonlinear process-induced spectral changes in hydrogenated amorphous silicon core optical fibre
摘要： In this paper, the spectral properties of temporal double pulses centred at the same central wavelength and two different central wavelengths are numerically presented based on hydrogenated amorphous silicon core optical fibre. In order to characterise the output spectra of double pulses, the group velocity dispersion and various nonlinear processes including self-phase modulation, cross-phase modulation, two-photon absorption, free carrier absorption and free carrier dispersion are considered in the theoretical model. Numerical results show that, under fixed fibre length condition, the widths of the outcome spectra are strongly dependent on the delay times, peak powers and initial chirps of input double pulses, i.e. widths of the output spectra are proportional to the launched peak powers, and the delay times control the separation between two pulses, resulting in the spectral change within a proper delay time, and the spectral widths are compressed or extended by judiciously adjusting the initial chirps imposed on the input pulses.
关键词： nonlinear processes,optical spectrum,optical fibre,Nonlinear optics,hydrogenated amorphous silicon
更新于2025-09-10 09:29:36
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AIP Conference Proceedings [Author(s) INTERNATIONAL CONFERENCE ON INVENTIVE MATERIAL SCIENCE APPLICATIONS: ICIMA-2018 - Tamil Nadu, India (27–28 September 2018)] - An optical millimeter wave generation using carrier suppression modulation scheme based on frequency 12 tupling lithium niobate mach zehnder modulator without an optical filter
摘要： This article presents a novel method for the generation of optical millimeter wave (mmw) from a microwave signal using a single Lithium Niobate Mach Zehnder Modulator (LiNbO3 MZM). The carrier suppression scheme supports the experimental setup for achieving 12-tupling frequency by suppressing the sidebands of wave signal by fixing the modulation and bias voltage as 10V. The absence of optical filter leads to fast tuning of required frequency by the modulator which helps to achieve 12 tupling frequencies effectively. The pseudorandom bit sequence in the rate of 50 Gbps is transmitted through a single mode optical fiber for a distance of 60 km. The experiment achieves a high data rate, less complexity and better performance in the absence of an optical filter and an amplifier when compared to other conventional methods. The proposed method performs error free transmission along the fiber of length 60 km and the efficiency of the generated mmw is analyzed by using optical spectrum, RF spectrum and eye diagram visualizers. The quality factor is also included in the paper using Bit Error Rate (BER) analyzer to prove that the energy loss is negligible in the setup.
关键词： Millimeter wave generation Radio over Fiber,Optical Spectrum,Frequency 12-tupling,Lithium Niobate Mach-Zehnder modulator,Optical carrier suppression
更新于2025-09-04 15:30:14
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Systematic analysis of the fine structure of energy level structures and spin-Hamiltonian parameters of V3+ ion in corundum with dynamic Jahn-Teller effect
摘要： Systematic analysis of fine structure of the whole energy levels and spin-Hamiltonian parameters ( zero-field splitting (ZFS) parameter D and g-factors g// and g?) for the ground state 3A2 ( 3T1 ) of V3+ ion in corundum are presented in detail with complete diagonalization method (CDM) of 45×45 energy matrix, in which the full configuration interactions are taken in account . The reduction of the splittings of excited electronic 3T2 ( t2ge ) term with orbital triplet degenerate caused by spin-orbit (SO) and lower trigonal crystal field (CF) is studied by T2?e model dynamic Jahn-Teller theory, and Ham deduction factor , the Jahn-Teller energy EJT and Huang-Rhys factor S are estimated. The studies are performed within the strong-field scheme with molecular orbit (MO) approximation, in which the two SO coupling parameter model is used and the SO contributions from both the central 3d ion and ligands are taken in account.The calculated results are in good agreement with the experimental data, and the local structure of [VO6]9- cluster with C3 point group symmetry are determined quantitatively.
关键词： Dynamic Jahn-Teller effect,Electron paramagnetic resonance,V3+ ion,Optical spectrum,Complete diagonalization method
更新于2025-09-04 15:30:14