Optical transmission through generalized third-order Fibonacci multilayers

2014 ◽  
Vol 28 (16) ◽  
pp. 1450129
Author(s):  
Xubo Hu ◽  
Xiangbo Yang ◽  
Songhao Liu
Keyword(s):  
Numerical Simulation ◽  
Electromagnetic Wave ◽  
Optical Transmission ◽  
Wave Theory ◽  
Third Order ◽  
Central Wavelength ◽  
Transmission Coefficients ◽  
Transmission Properties ◽  
Optical Memories ◽  
Simulation Results

In this paper, by means of three kinds of methods we study the transmission properties of the light through the quasiperiodic multilayers vertically following the generalized third-order Fibonacci (GTOF) sequences. By means of the decomposition–substitution (DS) method we predict that the GTOF systems possess an interesting four-cycle transmissive characteristic at the central wavelength. Based on the electromagnetic wave theory, we then deduce the formulae of propagation matrices and transmission coefficients analytically at the central wavelength and obtain the numerical simulation results at the same time. The results obtained by three kinds of methods accord with each other and three kinds of methods are complementary. The cyclic transmissive characteristics may be useful for the designing of some optical memories, optical logical gates, and other optical controlling devices.

A study of azimuthal electromagnetic wave LWD based on self-adaptive hp finite element method

2018 ◽  
Vol 32 (34n36) ◽  
pp. 1840073
Author(s):  
Hui Li ◽  
Yi-Bo Jiang ◽  
Jian-Wen Cai
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Electromagnetic Wave ◽  
Real Time ◽  
Simulation Results ◽  
Peak Value ◽  
Element Method ◽  
Self Adaptive ◽  
Hp Finite Element

Azimuthal electromagnetic wave logging-while-drilling (LWD) technology can detect weak electromagnetic wave signal and realize real-time resistivity imaging. It has great values to reduce drilling cost and increase drilling rate. In this paper, self-adaptive hp finite element method (FEM) has been used to study the azimuthal resistivity LWD responses in different conditions. Numerical simulation results show that amplitude attenuation and phase shift of directional electromagnetic wave signals are closely related to induced magnetic field and azimuthal angle. The peak value and polarity of geological guidance signals can be used to distinguish reservoir interface and achieve real-time geosteering drilling. Numerical simulation results also show the accuracy of the self-adaptive hp FEM and provide physical interpretation of peak value and polarity of the geological guidance signals.

scholarly journals Highly Stable All-Fiber-Ring Short-Cavity Continuously Tuned Swept Source

Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 328
Author(s):  
Zhiwei Yang ◽  
Xu Wu ◽  
Deqin Ouyang ◽  
Huibin Sun ◽  
Shuangchen Ruan
Keyword(s):  
Numerical Simulation ◽  
Optical Coherence Tomography ◽  
Spectral Width ◽  
Output Spectrum ◽  
Fiber Ring ◽  
Swept Source ◽  
Central Wavelength ◽  
Simulation Results ◽  
Oct Imaging ◽  
The Stability

In this study, we present a swept source that can intelligently control its sweeping speed while satisfying the commercial stability and miniaturization standards. The source’s central wavelength of the output spectrum is 1300 nm and spectral width is greater than 100 nm. Meanwhile, the scan frequency can be adjusted to range from 20 to 100 kHz, and the stability degree of the optical capacity is less than 0.34%. Additionally, this study establishes a numerical model for the swept-source optical coherence tomography (SS–OCT) system and introduces a numerical simulation of the signal produced during the OCT imaging process. The simulation results are helpful to guide the design and construction of the future OCT systems.

EFFECT OF DEVIATION ON OPTICAL TRANSMISSION THROUGH THUE–MORSE MULTILAYERS

2008 ◽  
Vol 22 (20) ◽  
pp. 1913-1921
Author(s):  
YUXING CHEN ◽  
XIANGBO YANG
Keyword(s):  
Thin Films ◽  
Optical Transmission ◽  
Critical Value ◽  
Transmission Property ◽  
Central Wavelength ◽  
Transmission Coefficients ◽  
Perfect System ◽  
Number Of Layers ◽  
Precise Machine ◽  
Simple Systems

In this paper, we propose a deviation model and consider the transmission property of Thue–Morse (TM) multilayers with deviations. It is found that at the central wavelength for very simple systems, the transmission coefficients (TCs) have nothing to do with the deviation of a machine, but when a multilayer system becomes more complex, one should use the most precise machine in order to make the system possess the designed value of TC. However, if superlattices become more complicated, one may choose a machine with a suitable relative error, but not the most accurate machine, to manufacture a perfect system. Additionally, after the number of layers exceeds some critical value, the very sophisticated optical superlattices could only be manufactured by very precise machines. The results would be useful for designing and manufacturing thin films of optical superlattices.

Transparent-Component-Decimation Method for Studying the Optical Transmission of One Kind of Aperiodic Superlattices

2011 ◽  
Vol 138-139 ◽  
pp. 1215-1220
Author(s):  
Xu Bo Hu ◽  
Jun Feng Li
Keyword(s):  
Optical Transmission ◽  
Central Wavelength ◽  
Transmission Coefficients ◽  
Bright Future ◽  
The Family ◽  
Decimation Method

Transparent-component-decimation (TCD) method may simplify the aperiodic sequences to the simplest form and one can obtain the transmissive characteristics without complicated calculations. Applying this method to the Family A of Generalized Thue-Morse [FAGTM(n)] aperiodic superlattices, we obtain directly the formulas of the transmission coefficients at the central wavelength. The results are in accord with the previous published results. It shows that the TCD method can be used to study optical transmission normally through aperiodic multilayers directly and exactly and has bright future.

scholarly journals Output Pulse Characteristics of a Mamyshev Fiber Oscillator

Photonics ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 590
Author(s):  
Haili Han ◽  
Nan-Kuang Chen ◽  
Liqiang Zhang ◽  
Yanru Xie ◽  
Zhen Tian ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Pulse Duration ◽  
Group Velocity Dispersion ◽  
Wide Spectrum ◽  
Output Pulse ◽  
Central Wavelength ◽  
Passive Fiber ◽  
Simulation Results ◽  
The One ◽  
Pulse Characteristics

The dependence of the output pulse characteristics of a Mamyshev fiber oscillator on cavity parameters is investigated in detail. We analyze the change in pulse spectrum bandwidth, pulse duration, dechirped pulse duration and chirp with the change in fiber group velocity dispersion, fiber nonlinearity, gain, and filters by putting forward a numerical model. In particular, as one of the most important components, the effect of filters bandwidth and the central wavelength interval between them is discussed. The passive fibers are classified into two kinds according to their locations in the cavity, which are the one before the gain fiber and the one after the gain fiber. Numerical simulation results show that a wide spectrum can be obtained by increasing the nonlinearity of the second passive fiber, while the change in nonlinearity of the first passive fiber has a weak effect on spectrum broadening. A wide spectrum could also be obtained by increasing the nonlinearity or the small-signal gain coefficient of the gain fiber. A Yb-doped Mamyshev fiber oscillator is demonstrated. The results show the increase in pump power, which agrees reasonably well with the numerical simulation results.

Avalanche Features in Silicon Schottky-FETs in Accordance with Numerical Simulation Results

2006 ◽  
Vol 65 (16) ◽  
pp. 1533-1546
Author(s):  
Yu. Ye. Gordienko ◽  
S. A. Zuev ◽  
V. V. Starostenko ◽  
V. Yu. Tereshchenko ◽  
A. A. Shadrin
Keyword(s):  
Numerical Simulation ◽  
Simulation Results

Tail shapes lead to different propulsive mechanisms in the body/caudal fin undulation of fish

2020 ◽  
pp. 095440622096768
Author(s):  
Jialei Song ◽  
Yong Zhong ◽  
Ruxu Du ◽  
Ling Yin ◽  
Yang Ding
Keyword(s):  
Numerical Simulation ◽  
Aspect Ratio ◽  
High Efficiency ◽  
The Body ◽  
Caudal Fin ◽  
Fish Model ◽  
Swimming Efficiency ◽  
Simulation Results ◽  
Propulsive Mechanism ◽  
High Depth

In this paper, we investigate the hydrodynamics of swimmers with three caudal fins: a round one corresponding to snakehead fish ( Channidae), an indented one corresponding to saithe ( Pollachius virens), and a lunate one corresponding to tuna ( Thunnus thynnus). A direct numerical simulation (DNS) approach with a self-propelled fish model was adopted. The simulation results show that the caudal fin transitions from a pushing/suction combined propulsive mechanism to a suction-dominated propulsive mechanism with increasing aspect ratio ( AR). Interestingly, different from a previous finding that suction-based propulsion leads to high efficiency in animal swimming, this study shows that the utilization of suction-based propulsion by a high- AR caudal fin reduces swimming efficiency. Therefore, the suction-based propulsive mechanism does not necessarily lead to high efficiency, while other factors might play a role. Further analysis shows that the large lateral momentum transferred to the flow due to the high depth of the high- AR caudal fin leads to the lowest efficiency despite the most significant suction.

scholarly journals Experiment and simulation about the effect of wear-ring abrasion on the performance of a marine centrifugal pump

2021 ◽  
Vol 13 (2) ◽  
pp. 168781402199811
Author(s):  
Wu Xianfang ◽  
Du Xinlai ◽  
Tan Minggao ◽  
Liu Houlin
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Pump ◽  
Pressure Pulsation ◽  
Vibration Velocity ◽  
Test Results ◽  
Obvious Effect ◽  
Performance Change ◽  
Pump Test ◽  
Simulation Results ◽  
Axis Passing

The wear-ring abrasion can cause performance degradation of the marine centrifugal pump. In order to study the effect of front and back wear-ring clearance on a pump, test and numerical simulation were used to investigate the performance change of a pump. The test results show that the head and efficiency of pump decrease by 3.56% and 9.62% respectively at 1.0 Qd due to the wear-ring abrasion. Under 1.0 Qd, with the increase of the front wear-ring the vibration velocity at pump foot increases from 0.4 mm/s to 1.0 mm/s. The axis passing frequency (APF) at the measuring points increases significantly and there appears new characteristic frequency of 3APF and 4APF. The numerical simulation results show that the front wear-ring abrasion affects the flow at the inlet of the front chamber of the pump and impeller passage. And the back wear-ring abrasion has obvious effect on the flow in the back chamber of the pump and impeller passage, while the multi-malfunction of the front wear-ring abrasion and back wear-ring abrasion has the most obvious effect on the flow velocity and flow stability inside pump. The pressure pulsation at Blade Passing Frequency (BPF) of the three schemes all decrease with the increase of the clearance.

scholarly journals Development of Depth-Limited Wave Boundary Layers over a Smooth Bottom

2020 ◽  
Vol 9 (1) ◽  
pp. 27
Author(s):  
Hitoshi Tanaka ◽  
Nguyen Xuan Tinh ◽  
Xiping Yu ◽  
Guangwei Liu
Keyword(s):  
Numerical Simulation ◽  
Boundary Layer ◽  
Boundary Layers ◽  
Wave Motion ◽  
Numerical Study ◽  
Experiment Data ◽  
Tidal Motion ◽  
Long Period ◽  
Simulation Results ◽  
Wave Boundary

A theoretical and numerical study is carried out to investigate the transformation of the wave boundary layer from non-depth-limited (wave-like boundary layer) to depth-limited one (current-like boundary layer) over a smooth bottom. A long period of wave motion is not sufficient to induce depth-limited properties, although it has simply been assumed in various situations under long waves, such as tsunami and tidal currents. Four criteria are obtained theoretically for recognizing the inception of the depth-limited condition under waves. To validate the theoretical criteria, numerical simulation results using a turbulence model as well as laboratory experiment data are employed. In addition, typical field situations induced by tidal motion and tsunami are discussed to show the usefulness of the proposed criteria.

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