- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Estimation of Signal-to-Cross Talk Ratio of Stimulated-Raman-Scattering-Induced Cross Talk in Wavelength-Division-Multiplexing-Based Radio-over-Fiber Links
摘要： This paper evaluates the signal-to-cross talk ratio (SXR) of cross talk induced by stimulated Raman scattering (SRS) in radio-over-fiber (RoF) systems based on wavelength-division multiplexing. The reported study has modeled the relations of SXR to modulation frequency, optical power, transmission length, and effective area of fiber for various values of the walk-off parameter. The summary of experimental reveals that SXR decreases with increases in channel input power and transmission distance and increased with increases in fiber effective area and modulation frequency. Results showed that increasing the walk-off parameter from 13.6 to 81.6 ps/km increased the SXR by almost 6 dBm. Furthermore, various fibers, including standard single-mode fiber (SMF), Corning LEAF, and Alcatel TeraLight were tested for their capacity to mitigate SRS-induced cross talk. These tests demonstrated that standard SMF suppressed SRS cross talk effectively and offered values of SXR 3 dBm and 6 dBm higher than the values exhibited by Alcatel TeraLight and Corning LEAF, respectively.
关键词： wavelength-division multiplexing (WDM),signal-to-cross talk ratio (SXR),stimulated Raman scattering (SRS),single-mode fiber (SMF),radio over fiber (RoF)
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE 13th Annual International Conference on Nano/Micro Engineered and Molecular Systems (NEMS) - Singapore, Singapore (2018.4.22-2018.4.26)] 2018 IEEE 13th Annual International Conference on Nano/Micro Engineered and Molecular Systems (NEMS) - Novel Mechanical Coupling Piezoelectric Micromachined Ultrasonic Transducers Based on Base Excitation System
摘要： This paper presented a novel piezoelectric micromachined ultrasonic transducer (PMUT) based on mechanical coupling between an annular diaphragm and a circular diaphragm stacking together. The circular diaphragm whose pedestal grounded on the middle of the annular diaphragm, which formed a base excitation system. Compared to the non-coupled traditional circular diaphragm PMUTs, the proposed PMUTs achieved higher transmission sensitivity by 173% with the resonant frequency of 6.14 MHz in water, due to the base excitation amplification of the circular diaphragm. Also, the array transmission performance of the proposed PMUT and non-coupled traditional PMUT with circular diaphragm was compared in the same array dimension. The results indicated that the array composed by the proposed PMUT had less cross-talk effect, which kept the central working frequency almost the same when it work solely.
关键词： mechanical coupling,PMUT,high transmission sensitivity,low cross-talk effect
更新于2025-09-19 17:15:36
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Control and calibration recipes for photonic integrated circuits
摘要： This paper presents the key ingredients and the best practices for implementing simple, effective and robust control and calibration procedures for arbitrary photonic integrated circuit (PIC) architectures. Three main features are presented and discussed: a technique to cancel out the effects of mutual crosstalk among thermal tuners, the exploitation of labelling to identify different optical signals, the use of input modulated signal to automatically reshape the frequency response of the device. Examples of application are then illustrated to show the validity and generality of the approach, namely a cross-bar interconnect matrix router, a variable bandwidth filter and third order coupled microring filter. Further, the automatic and dynamic generation of the lookup table of add/drop hitless filters operating on a dense wavelength division multiplexing grid is demonstrated. The lookup table achieved with the proposed approach can dynamically update itself to new conditions of the chip or new requirements of operation, such as variations in channel modulation format or perturbation induced by neighboring devices due to a change in their working point.
关键词： control,optical filters,microring resonators,pilot tones,integrated photonics,calibration,look up tables,thermal cross talk,tuning,locking
更新于2025-09-16 10:30:52
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Low cross-talk waveguide intersections for TE polarization using photonic crystals
摘要： In this paper, two low cross-talk and wide bandwidth waveguide intersections are proposed based on novel types of resonators which are created using rotated photonic crystal lattices. A lattice of the air holes in a GaAs substrate is used to realize the waveguides. By inserting a second lattice of holes which resembles the main lattice, with a particular amount of scaling and rotation, we have created a resonator which can diminish the cross-talk in waveguide intersections. Two new topologies have been proposed based on the mentioned resonators, one with two sets of waveguides (four arms) and the other one with three sets of the waveguides (six arms). Plane wave expansion (PWE) and finite difference time domain (FDTD) methods are used for numerical simulation of the intersections. Simulation results indicate that a bandwidth of 49.1 nm and a cross-talk level of -40 dB can be obtained for the intersection of two waveguides using the configuration proposed in this paper.
关键词： Cross-talk,Optical waveguide,Photonic crystal,Integrated optics,Waveguide intersection
更新于2025-09-12 10:27:22
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Evaluation of Switching Loss Contributed by Parasitic Ringing for Fast Switching Wide Band-Gap Devices
摘要： Parasitic ringing is commonly observed during the high-speed switching of wide band-gap (WBG) devices. Additional loss contributed by parasitic ringing becomes a concern especially for high switching frequency applications. This paper investigates the effects of parasitic ringing on switching loss of WBG devices in a phase-leg configuration. An analytical switching loss model considering parasitics in power devices and application circuit is derived. Two switching commutation modes, gate drive dominated mode and power loop dominated mode, are investigated, respectively, and the switching loss induced by damping ringing is identified. It is found that this portion of the loss is at most the energy stored in parasitics, which always exists regardless of the switching speed and parasitic ringing. Therefore, with the given WBG device in the specific application circuit, damping more severe parasitic ringing during faster switching transient would not introduce higher switching loss. Additionally, the extra switching loss induced by resonance among parasitics and cross-talk is investigated. It is observed that severe resonance and its resultant over-voltage during the turn-on transient worsens the cross-talk, causing large shoot-through current and excessive switching loss. The theoretical analysis has been verified by the double pulse test with a 1200-V/50-A SiC-based phase-leg power module.
关键词： fast speed switching,switching loss,parasitic ringing,overshoot voltage,cross-talk,Wide Bandgap
更新于2025-09-09 09:28:46
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[Papers] Quantum Efficiency Simulation and Electrical Cross-talk Index Development with Monte-Carlo Simulation Based on Boltzmann Transport Equation
摘要： This paper explains a new method to model a photodiode for accurate quantum efficiency simulation. Individual photo-generated particles are modeled by Boltzmann transport equation, and simulated by Monte-Carlo method. Good accuracy is confirmed in terms of similarities of quantum efficiency curves, as well as color correction matrices and SNR10s. Three attributes - "initial energy of the electron", "recombination of electrons at the silicon surface" and "impurity scattering" - are tested to examine their effectiveness in the new model. The theoretical difference to the conventional method with drift-diffusion equation is discussed as well. Using the simulation result, the relationship among the cross-talk, potential barrier, and distance from the boundary has been studied to develop a guideline for cross-talk suppression. It is found that a product of the normal distance from the pixel boundary and the electric field perpendicular to the Z-axis needs to be more than 0.02V to suppress the probability of electron leakage to the adjacent pixel to less than 10%.
关键词： cross-talk,quantum efficiency,simulation,image sensor,BTE,Boltzmann transport equation
更新于2025-09-09 09:28:46
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A quad polarimetric SAR calibration algorithm using rotation symmetry
摘要： Polarimetric calibration, precisely deciphering the polarimetric information hidden in the polarized characteristics of a radar scene, is the core step before applying quad polarimetric synthetic aperture radar (PolSAR) data for ground parameter inversion and classification. The previously published techniques for polarimetric calibration generally use at least one known point calibration target to completely determine the polarimetric distortions (cross-talks and channel imbalances) between the various polarized channels. This paper describes a novel method that solely relies on the image itself with the property of rotation symmetry. The algorithm derives the entire cross-talk and channel imbalance parameters using an iterative operation to circularly modify the observed average covariance matrix, which is independent on the known point calibration targets in the illuminated scene. The proposed method is validated to be reliable and efficient through polarimetric calibration experiments using the airborne C-band and RadarSat-2 quad polarimetric SAR images. The experimental results indicate that the new technique achieves similar calibration precision to the Ainsworth algorithm but without using any known calibration point target.
关键词： Polarimetric calibration,cross-talk,channel imbalance,quad polarimetric SAR,rotation symmetry
更新于2025-09-09 09:28:46
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Optical sectioning in multifoci Raman hyperspectral imaging
摘要： In this study, we compared the depth discrimination and speed performance of multifoci Raman hyperspectral imaging with the reference standard of a single laser point confocal Raman mapping. A liquid crystal spatial light modulator was employed for the generation of multifoci laser beams, and a digital micromirror device was used as a software‐configurable reflective pinhole array. The patterns of the laser foci and pinhole array can be rapidly changed without requiring any hardware alterations. Confocal patterns with different distance‐to‐size ratios were tested and compared. After optimization of the laser‐foci pattern, we demonstrated the feasibility of multifoci Raman hyperspectral microscopy for recording depth‐resolved molecular maps of biological cells (Acanthamoeba castellanii trophozoites). Micrometric depth discrimination and short acquisition times (20 min for single plane confocal image) were achieved.
关键词： single cell imaging,cross‐talk,confocal Raman imaging,multi‐beam,optical sectioning
更新于2025-09-04 15:30:14