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- 摘要
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- 实验方案
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A widely tunable bandpass filter adopting novel fully tunable resonators
摘要： A widely tunable bandpass filter adopting a novel fully tunable resonator is proposed in this letter. The fully tunable resonator is mainly consisted of an open ring, a frequency tuning structure, and a coupling tuning structure. Adopting the fully resonators, the center frequency, the input/output external Q value, and the coupling coefficients can be tuned at the same time. And the tuning range of a tunable filter adopting the novel fully tunable resonators can be expanded. The fully tunable resonators can be combined to achieve more excellent suppression performance. A widely tunable bandpass filter consisted of five fully tunable resonators with 86.5% frequency tuning range is designed, fabricated, and measured. The simulated results are in good agreement with the measured ones.
关键词： widely tunable filter,coupling tuning structure,open ring,fully tunable resonators,more excellent suppression
更新于2025-09-23 15:23:52
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AIP Conference Proceedings [Author(s) 4TH ELECTRONIC AND GREEN MATERIALS INTERNATIONAL CONFERENCE 2018 (EGM 2018) - Bandung, Indonesia (27–28 July 2018)] - Design and analysis of fiber Bragg grating tunable filter utilizing thermal technique
摘要： In this paper a tunable filter based on fiber Bragg grating (FBG) utilizing thermal technique is theoretically investigated and experimentally validated. According to the results, a tuning range is achieved about 1.5 nm in C-band region. While, for L-band region the wavelength shift is slightly greater than in the C-band region about 1.6 nm. This shifting is due to changing in thermo-optic and thermal expansion of fiber, which causes changing in refractive index and then Bragg wavelength. The experimental validation is done at wavelength 1552.7 nm, the tunability is about 1.2428 nm when the temperature is varied from 21°C to 61°C.
关键词： thermal expansion,fiber Bragg grating,thermo-optic effect,thermal technique,tunable filter
更新于2025-09-23 15:23:52
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[IEEE 2018 Wave Electronics and its Application in Information and Telecommunication Systems (WECONF) - Saint-Petersburg, Russia (2018.11.26-2018.11.30)] 2018 Wave Electronics and its Application in Information and Telecommunication Systems (WECONF) - Temperature Measurement Using Endoscopic Acousto-Optical Spectral Imaging System
摘要： The problem of measuring spatial temperature distribution over the surface of hard-to-reach objects with a non-uniform emissivity distribution is considered. We propose to solve it using acousto-optical spectral imaging system. This approach enables precise non-contact temperature measurements as well as contrast visualization in arbitrary narrow spectral bands. The temperature measurement of filament lamp using rigid borescope and acousto-optic imaging filter is presented.
关键词： endoscopy,non-destructive testing,spectral imaging,temperature measurement,acousto-optical tunable filter
更新于2025-09-23 15:22:29
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The AOTF-based NO<sub>2</sub> camera
摘要： The abundance of NO2 in the boundary layer relates to air quality and pollution source monitoring. Observing the spatiotemporal distribution of NO2 above well-delimited (flue gas stacks, volcanoes, ships) or more extended sources (cities) allows for applications such as monitoring emission fluxes or studying the plume dynamic chemistry and its transport. So far, most attempts to map the NO2 field from the ground have been made with visible-light scanning grating spectrometers. Benefiting from a high retrieval accuracy, they only achieve a relatively low spatiotemporal resolution that hampers the detection of dynamic features. We present a new type of passive remote sensing instrument aiming at the measurement of the 2-D distributions of NO2 slant column densities (SCDs) with a high spatiotemporal resolution. The measurement principle has strong similarities with the popular filter-based SO2 camera as it relies on spectral images taken at wavelengths where the molecule absorption cross section is different. Contrary to the SO2 camera, the spectral selection is performed by an acousto-optical tunable filter (AOTF) capable of resolving the target molecule's spectral features. The NO2 camera capabilities are demonstrated by imaging the NO2 abundance in the plume of a coal-fired power plant. During this experiment, the 2-D distribution of the NO2 SCD was retrieved with a temporal resolution of 3 min and a spatial sampling of 50 cm (over a 250 × 250 m2 area). The detection limit was close to 5 × 1016 molecules cm?2, with a maximum detected SCD of 4 × 1017 molecules cm?2. Illustrating the added value of the NO2 camera measurements, the data reveal the dynamics of the NO to NO2 conversion in the early plume with an unprecedent resolution: from its release in the air, and for 100 m upwards, the observed NO2 plume concentration increased at a rate of 0.75–1.25 g s?1. In joint campaigns with SO2 cameras, the NO2 camera could also help in removing the bias introduced by the NO2 interference with the SO2 spectrum.
关键词： NO2,AOTF,plume,remote sensing,air quality,camera,acousto-optical tunable filter
更新于2025-09-23 15:22:29
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Strong Coupling of Magnons to Microwave Photons in Three-Dimensional Printed Resonators
摘要： We report on ferromagnetic resonant mode hybridization in re-entrant cavities made with a commercial three-dimensional (3D) printer, followed by conventional 3D metalization with copper and tin. The cavity volume was only 7% that of a standard cavity resonating at the same frequency, while maintaining a high quality factor. Simulations were in very good agreement. We obtained an effective coupling of about 40 MHz in two cavities at room temperature. These experimental results demonstrate the utility of tunable filters based on complex 3D printed cavities.
关键词： magnon photon polariton,3D Cavity spintronic,Yttrium Iron Garnet,3D printing,tunable filter
更新于2025-09-23 15:22:29
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Simple Coupled-Line Tunable Bandpass Filter With Wide Tuning Range
摘要： In this paper, a tunable bandpass filter using coupled line with a wide tuning range is proposed. The proposed filter has a simple structure which is composed of a coupled-line section and two pairs of varactors. Meanwhile, simultaneously tuning on bandwidth and center frequency are introduced by varactors. The tunability is mainly realized by varactors connected to one end of the coupled line and varactors between port and coupled line provides an impedance matching. A theoretical analysis is presented to illustrate the tunability by using even- and odd-mode theory. Additionally, the detailed effect of the two types of varactors is researched, respectively. To verify the concept, a prototype is designed, fabricated, and measured. The transmission zero exhibited in measurement is introduced by bias circuits. The measured results show that the tunable bandpass filter achieves a tunable center frequency of 0.494-1.257 GHz (87.15%) and a 3-dB bandwidth of 0.282-0.943 GHz (334%).
关键词： wide tuning range,tunable filter,Bandpass filter,coupled line
更新于2025-09-23 15:21:01
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A phase-change thin film-tuned photonic crystal device
摘要： This paper reports a tunable photonic device that incorporates a thin layer of phase-change material, Ge2Sb2Te5 (GST), in a photonic crystal (PC) structure. The PC structure is based on a one-dimensional grating waveguide with a metal cladding. The metal-cladded PC structure supports a guided-mode resonance (GMR) that selectively absorbs light at a particular wavelength. Inserting the GST material into the gating waveguide makes it possible to control the GMR mode. Here, the GST-PC device was numerically designed and optimized to obtain significant tuning of the GMR mode around 1550 nm. The tuning phenomena were experimentally demonstrated by the heat-induced phase change between crystalline and amorphous phases of the GST thin film. A spectral shift of the resonant wavelength from 1440 nm to 1610 nm was achieved via the crystallization process. The phase tuning of GST exhibits good repeatability as demonstrated by switching between amorphous and crystalline phases of GST for multiple cycles. The GST-PC device represents a new approach for tuning optical resonances with potential applications including but not limited to integrated photonic circuits, optical communications, and high-performance optical filters.
关键词： tunable filter,Photonic crystal,phase-change material
更新于2025-09-23 15:21:01
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[IEEE 2018 Second International Conference on Computing Methodologies and Communication (ICCMC) - Erode (2018.2.15-2018.2.16)] 2018 Second International Conference on Computing Methodologies and Communication (ICCMC) - STORE WHEN BLOCKED AFTER FAIR PRIORITIZED PREEMPTION (SBFPP) PROTOCOL FOR NON BLOCKING OPTICAL BURST SWITCHED NETWORKS
摘要： Just Enough Time is the most promising protocol of optical burst switched network, Different prioritization on the basis of fairness algorithms have been given for increasing the utilization of link. Still there is probability of blocking in the network at high load. In this Paper we have proposed a none blocking Optical Burst Switched network by proposing a new protocol for optical Burst switched network. In this paper we have also compared the blocking probabilities of JET with some fairness protocols with our proposed protocol. A simulated output for effective bandwidth utilization and dropping probabilities of all the outputs are also presented and compared.
关键词： Fair Prioritized Preemption (FPP),Acoustic Optical tunable filter (AOTF),Optical Burst Switching,Last available unscheduled channel with void filling (LAUC-VF)
更新于2025-09-23 15:21:01
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Performance improved tunable millimeter-wave signal generation employing UFBG based AOTF with bit walk-off effect compensation
摘要： A scheme for the generation of mm-wave signals at different frequencies with improved performance is proposed and demonstrated by employing a uniform fiber Bragg grating based acousto-optic tunable filter (UFBG-AOTF). The different frequencies carry different information at a required data rate according to their application. This method reduces the complexity of the system by alleviating the cascaded Mach-Zehnder modulators (MZM) and a good transmission performance can be achieved by the FBG. In the previous system, the distance of transmission is reduced to 15 km due to bit walk-off effect and it also reduces the BER values at larger distances. In the proposed system, the bit walk-off effect is discussed and compensated to increase the transmission distance up to 60 km. The simulation results along with clear eye-diagrams show that the BER values are improved at larger distances than the previous system which proves the performance improvement of the proposed system.
关键词： optical millimeter-wave,radio-over-fiber,bit walk-off effect,acousto-optic tunable filter,uniform fiber Bragg grating
更新于2025-09-19 17:15:36
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Continuously tunable fiber laser based on Fano resonance filter of thin-fiber-taper-coupled conical microresonator
摘要： Through Fano resonance, the resonant modes exhibiting peak-like shapes on the bandpass spectrum of the thin-fiber-taper-coupled conical microresonator are generated. For the first time, this thin-fiber-taper-coupled conical microresonator functions as a Fano filter, and is applied as a tunable internal-cavity bandpass filter for an Erbium-doped fiber ring laser. If the size of the conical microresonator in the coupling junction is adjusted by displacing the fiber taper along the resonator axis, the wavelength of the output laser is able to be tuned linearly and continuously with a coefficient of 0.225 nm/mm.
关键词： Fano resonance,Conical microresonator,Fiber ring laser,Whispering gallery mode,Tunable filter
更新于2025-09-19 17:13:59