scholarly journals Pulse-Propagation Modeling and Experiment for Femtosecond-Laser Writing of Waveguide in Nd:YAG

Crystals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 434 ◽  
Author(s):  
Tao Feng ◽  
Pankaj K. Sahoo ◽  
Francisco R. Arteaga-Sierra ◽  
Christophe Dorrer ◽  
Jie Qiao
Keyword(s):  
Femtosecond Laser ◽  
Experimental Validation ◽  
Pulse Propagation ◽  
Experimental Results ◽  
Propagation Loss ◽  
Type Ii ◽  
Input Energy ◽  
Propagation Equation ◽  
Propagation Modeling ◽  
Simulation Results

In this work, unidirectional pulse propagation equation (UPPE) modeling is performed to study the nonlinear laser-mater interaction in silicon and Nd:Y3Al5O12 (Nd:YAG) crystals. The simulation results are validated with reported experimental results for silicon and applied to Nd:YAG crystals with experimental validation. Stress-induced waveguides are written in Nd:YAG crystals using 515 nm, 300 fs pulses at a 1 kHz repetition rate. Waveguides having a mean propagation loss of 0.21 ± 0.06 dB/cm are obtained, which is lower than the previous reported values for Type-II waveguides written in Nd:YAG crystals. The modeling and experimental results consistently show that the modification (waveguide track) depth increases with input energy. A detailed analysis is presented to control the modal properties of the waveguide in the context of UPPE simulation.

scholarly journals Throughput Improvement in Femtosecond Laser Ablation of Nickel by Double Pulses

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6355
Author(s):  
Kunpeng Chu ◽  
Baoshan Guo ◽  
Lan Jiang ◽  
Yanhong Hua ◽  
Shuai Gao ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Delay Time ◽  
Femtosecond Laser Ablation ◽  
Experimental Results ◽  
Energy Ratio ◽  
Ablation Efficiency ◽  
Pulse Delay ◽  
Throughput Improvement ◽  
Energy Ratios ◽  
Simulation Results

In this study, femtosecond laser double pulses were tested to improve their nickel ablation efficiency. The experimental results indicated that compared with single pulses, double pulses with different delay times generated craters with larger diameters and depths. The results obtained for three sets of double pulses with different energy ratios indicated that double pulses with an energy ratio of 1:9 had the highest ablation efficiency, followed by those with energy ratios of 2:8 and 5:5. The double pulses with the aforementioned three energy ratios achieved the maximum ablation efficiency when the delay time was 3–4 ps. Compared with single pulses, double pulses with an energy ratio of 1:9 generated craters with an up to 34% greater depth and up to 14% larger diameter. In addition, an interference effect was observed with a double pulse delay time of 0 ps, which has seldom been reported in the literature. The double pulses were simulated using the two-temperature model. The simulation results indicated that double pulses with an energy ratio of 1:9 with a delay time of 4 ps can perform the strongest ablation. These simulation results are in line with the experimental results.

scholarly journals Design and Characterization of a Microwave Planar Sensor for Dielectric Assessment of Vegetable Oils

Electronics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 1030 ◽  
Author(s):  
Aleksandr Ivanov ◽  
Timur Agliullin ◽  
Dario Laneve ◽  
Vincenza Portosi ◽  
Artem Vorobev ◽  
...  
Keyword(s):  
Dielectric Permittivity ◽  
Electric Field ◽  
Numerical Simulations ◽  
Vegetable Oils ◽  
Experimental Validation ◽  
Experimental Results ◽  
Geometrical Parameters ◽  
Frequency Range ◽  
Simulation Results

We report on the numerical simulations and experimental validation of a microwave planar sensor based on two coupled rings operating in the 4–6 GHz range. The fabricated sensor is used to characterize the dielectric permittivity of vegetable oils. We optimized the geometrical parameters in order to improve the overlap between the oil samples under study and the electric field. The experimental results showed an excellent match with the simulation results. The fabricated sensor allowed to retrieve the oil permittivity with a sensitivity of about 35 MHz per permittivity unit in the frequency range of interest. This paves the way to the realization of compact and sensitive sensors for a wide plethora of fields ranging from industry and food to chemistry and biology.

Simulation of carding condensing process

2021 ◽  
pp. 004051752098812
Author(s):  
Xixi Qian ◽  
Yuanying Shen ◽  
Qiaoli Cao ◽  
Jun Ruan ◽  
Chongwen Yu
Keyword(s):  
Experimental Results ◽  
Simulation Results ◽  
Carding Machine ◽  
The Web

A simulation describing the fiber movement during the condensation was conducted, and the effect of the condensation in the carding machine was studied. The simulation results showed that the condensation has the blending and the evening effect on the condensed sliver, which can be explained by the fiber rearrangement. Moreover, the increasing web width and the decreasing condensing length can result in a more uniform sliver. Further, the evening effect of the web width on the web was verified by experiments. The simulation results were in general agreement with the experimental results.

Modulation instability in nonlinear chiral fiber

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Demissie Jobir Gelmecha ◽  
Ram Sewak Singh
Keyword(s):  
Theoretical Model ◽  
Numerical Simulations ◽  
Pulse Propagation ◽  
Modulation Instability ◽  
Constitutive Relations ◽  
Gain Spectrum ◽  
Circularly Polarized ◽  
Left Handed ◽  
Simulation Results ◽  
The Difference

AbstractIn this paper, the rigorous derivations of generalized coupled chiral nonlinear Schrödinger equations (CCNLSEs) and their modulation instability analysis have been explored theoretically and computationally. With the consideration of Maxwell’s equations and Post’s constitutive relations, a generalized CCNLSE has been derived, which describes the evolution of left-handed circularly polarized (LCP) and right-handed circularly polarized (RCP) components propagating through single-core nonlinear chiral fiber. The analysis of modulation instability in nonlinear chiral fiber has been investigated starting from CCNLSEs. Based on a theoretical model and numerical simulations, the difference on the modulation instability gain spectrum in LCP and RCP components through chiral fiber has been analyzed by considering loss and chirality into account. The obtained simulation results have shown that the loss distorts the sidebands of the modulation instability gain spectrum, while chirality modulates the gain for LCP and RCP components in a different manner. This suggests that adjusting chirality strength may control the loss, and nonlinearity simultaneously provides stable modulated pulse propagation.

Coupled Pitch Links for Multiharmonic Isolation Using Fluidic Circuits

2014 ◽  
Vol 59 (4) ◽  
pp. 1-11
Author(s):  
Lloyd H. Scarborough III ◽  
Christopher D. Rahn ◽  
Edward C. Smith ◽  
Kevin L. Koudela
Keyword(s):  
Experimental Validation ◽  
Analytical Models ◽  
Main Rotor ◽  
Fluidic Devices ◽  
Simulation Results ◽  
Fluidic Circuits ◽  
Blade Loads

Replacing stiff pitch links on rotorcraft with coupled fluidic devices has the potential to reduce the aerodynamic blade loads transmitted through the pitch links to the swashplate. Analytical models of two fluidic devices coupled with three different fluidic circuits are derived. These passive fluidlastic systems are tuned, by varying the fluid inertances and capacitances of each fluidic circuit, to reduce the transmitted pitch-link loads. The different circuit designs result in transmitted pitch-link loads reduction at up to three main rotor harmonics. The simulation results show loads reduction at the targeted out-of-phase and in-phase harmonics of up to 88% and 93%, respectively. Experimental validation of two of the fluidic circuits demonstrates loads reduction of up to 89% at the out-of-phase isolation frequencies and up to 81% at the in-phase isolation frequencies.

The Effect of Different Turbulence Models on the Emitter Discharge by Using Computational Fluid Dynamics

2013 ◽  
Vol 662 ◽  
pp. 586-590
Author(s):  
Gang Lu ◽  
Qing Song Yan ◽  
Bai Ping Lu ◽  
Shuai Xu ◽  
Kang Li
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Turbulence Models ◽  
Experimental Results ◽  
Turbulent Model ◽  
Simulation Results ◽  
Rsm Model ◽  
Dynamics Method ◽  
Emitter Discharge

Four types of Super Typhoon drip emitter with trapezoidal channel were selected out for the investigation of the flow field of the channel, and the CFD (Computational Fluid Dynamics) method was applied to simulate the micro-field inside the channel. The simulation results showed that the emitter discharge of different turbulent model is 4%-14% bigger than that of the experimental results, the average discharge deviation of κ-ω and RSM model is 5, 4.5 respectively, but the solving efficiency of the κ-ω model is obviously higher than that of the RSM model.

Design of Magnetic Levitated Thrust Bearing Experiment Table

2011 ◽  
Vol 199-200 ◽  
pp. 597-602
Author(s):  
Shou Fa Liu ◽  
Zhang Jie Shi ◽  
Chun Feng Li
Keyword(s):  
Thrust Bearing ◽  
Deformation Measurement ◽  
Experimental Results ◽  
Electromagnetic Parameters ◽  
Ansys Simulation ◽  
Overall Design ◽  
Experimental Parameters ◽  
Structural Dimensions ◽  
Simulation Results

In this paper, the overall design of magnetic levitated thrust bearing experiment table was completed, of which the main experimental parameters those are electromagnetic parameters and structural dimensions were determined, in addition, the joint debugging and deformation measurement are performed. Analysis results showed that theoretical value, ANSYS simulation results and experimental results were similar, which said that it is feasible to perform stiffness check of the thrust collar on the experiment table.

scholarly journals Numerical Simulations of V-Shaped Plates Subjected to Blast Loadings: A Validation Study

2016 ◽  
Vol 10 (11) ◽  
pp. 203
Author(s):  
Mohd Zaid Othman ◽  
Qasim H. Shah ◽  
Muhammad Akram Muhammad Khan ◽  
Tan Kean Sheng ◽  
M. A. Yahaya ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Numerical Simulations ◽  
Variable Mass ◽  
Blast Loading ◽  
Experimental Results ◽  
Average Difference ◽  
Simulation Results ◽  
Blast Loadings ◽  
Carrier Vehicle ◽  
Good Agreement

A series of numerical simulations utilizing LS-DYNA was performed to determine the mid-point deformations of V-shaped plates due to blast loading. The numerical simulation results were then compared with experimental results from published literature. The V-shaped plate is made of DOMEX 700 and is used underneath an armour personal carrier vehicle as an anti-tank mine to mitigate the effects of explosion from landmines in a battlefield. The performed numerical simulations of blast loading of V-shaped plates consisted of various angles i.e. 60°, 90°, 120°, 150° and 180°; variable mass of explosives located at the central mid-point of the V-shaped vertex with various stand-off distances. It could be seen that the numerical simulations produced good agreement with the experimental results where the average difference was about 26.6%.

Random-Access Multilevel Storage in Phase Change Memory by Staircase-Like Pulse Programming

2011 ◽  
Vol 497 ◽  
pp. 111-115
Author(s):  
Ryota Kobayashi ◽  
Tomoyuki Noguchi ◽  
You Yin ◽  
Sumio Hosaka
Keyword(s):  
Phase Change ◽  
Phase Change Memory ◽  
Random Access ◽  
Experimental Results ◽  
Device Resistance ◽  
Multilevel Storage ◽  
Simulation Results ◽  
Change Memory

We have investigated random-access multilevel storage in phase change memory by staircase-like pulse programming. Staircase-like pulse consists of first sub-pulse and second sub-pulse. Our simulation exhibited that any resistance levels are expected to be randomly accessed by controlling the crystallization with different widths of second sub-pulset2. Based on the simulation results, we did experiment on staircase-like pulse programming. Experimental results showed that the device resistance gradually increased with reducing second sub-pulset2to 0 ns. In other words, random access to any resistance levels was demonstrated to be possible simply by changingt2.

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