This paper studies wave power generation technology and designs a cross-wave generator based on S- type blade. When immersed in quiescent fluid, the device operates by changing the magnetic flux. The S-type blades can more effectively utilize the sea energy and improve the power generation efficiency of the waves. The device has stable performance, high efficiency, simple and practical, which is significant for the development of clean and renewable energy.
Abstract The generation of supercontinuum (SC) is the result of nonlinear effect and dispersion. In order to better understand the broadening mechanism of SC, this paper studies the influences of various dispersions on SC generation and evolution in photonic crystal fiber.
Using the methods based on the technique of self-similar analyzing, we find the parabolic asymptotic self-similar analytical solutions with third-order dispersion effect of constant coefficient Ginzburg-Landau equation which considers both the influence of high order dispersion and gain dispersion on the evolution of self-similar pulse. The self-similar amplitude function, phase function, strict linear chirp function and effective temporal pulse width are given in the paper. The results show that self-similar pulses still have linear chirp and remarkable third-order dispersion effect. And these theoretical results are consistent with numerical simulations.
A novel multi-channel wavelength demultiplexer (WDM) consisting of metal-insulator-metal waveguides and asymmetrically coupled nanodisk resonators is designed and simulated. The results show the WDM can export any single mode while undesirable modes are suppressed.
The evolution properties of the self-similar parabolic pulse(similariton) with higher-order effects in microstructured fiber amplifier with normal group-velocity dispersion are investigated in this paper. The numerical results show that the higher-order effects greatly distort similariton's waveform, frequency and the linearity of chirp. The drift of pulse center increases with distance. The influence of different higher-order effects on similariton is analyzed. High quality propagation of similariton can be attained by manipulating the geometrical parameters of the microstructured fiber amplifier. These results are significant in the further study of similariton propagation in high-power ultrashort fiber amplifier, laser and transmission system.
The decoherence of two qubits, coupled with one-mode cavity separately, has been investigated exactly. The results show that, for the resonant case, the decoherence behavior of system is similar to Markovian case when the coupling strength is weak, while the concurrence vanishes in finite time and might recover fractional initial entanglement before it permanently vanishes when the coupling strength is strong. And for detuning case, the entanglement could periodically recover after a period of time from its disappearance. These results are quite different from that of system subjected to Jaynes-Cummings model.
Airy beams have received considerable attention due to their unique features on propagation, including non-spreading, self-healing, self-accelerating, and parabolic trajectories. Here in this work we study the propagation of linearly polarized Airy beams with an added spherical phase in uniaxial crystal orthogonal to the optical axis. Based on the beam transmission theory in uniaxial crystals, the analytical expressions for the intensity distribution of the beams in different view planes are derived. Numerical calculations are performed and some novel propagation features are presented graphically. It is shown that the Airy beam with an added spherical phase remains linearly polarized but cannot keep other properties unchanged during propagation in uniaxial crystal. Such a beam maintains its intensity profile in the near-field, then with the propagation distance increasing, converts into the Gaussian-Airy beams with different orientations at two specified distances which are codetermined by the extraordinary and ordinary refractive index of the crystal (namely <i>n</i><sub>e</sub> and <i>n</i><sub>o</sub>) and the radius of the spherical phase, and most impressively, forms a mirror-like reflection profile in the far field, i.e., the intensity pattern in the far field returns to the initial Airy beam profile while its orientation on the transversal plane is reversed along the bisector line of the second and fourth quadrant. Note that the intensity pattern successively experiences two mirror transformations along the <i>x</i> and <i>y</i> coordinate axis when passing through these two critical positions, which can give rise to the mirror reflection effect for the whole Airy beam. Moreover, we further demonstrate that the sequences of these two mirror transformations are in close relation with the relative size between <i>n</i><sub>e</sub> and <i>n</i><sub>o</sub>. Therefore, the results obtained in this paper reveal new propagation features in anisotropic medium of Airy beams with added spherical phase and provide a novel route to controlling propagation properties like the pattern profile and orientation of the Airy beams through choosing appropriate anisotropic materials and the radius of the spherical phase factor. Considering that it is easy to obtain an Airy beam with an added spherical phase which can be realized with an Airy beam through an ideal lens, our investigation may lead to potential applications in many fields where the ability to change profile and orientation of the intensity pattern and the ability to determine the refractive index of anisotropic medium are both required.
In this paper, we investigate the Innovative and Entrepreneurship Education in electronics and information engineering under the background of emerging engineering education. Firstly, the innovation and entrepreneurship education system of electronic information engineering, which is composed of general education, professional education and innovation and entrepreneurship practice, is researched. Secondly, the teaching method of innovation and entrepreneurship course in electronic information engineering is discussed. Then the organization of students to participate is studied in various discipline competitions. Finally the cooperation of schools and enterprises is proposed. The results not only provides guidance for the students' innovation and entrepreneurship, but also helps to strengthen the close relationship between the development of higher education and local economic development.
Abstract Supercontinuum is widely used in spectroscopy, optical communication system, national defense security, biomedicine and other fields because of its wide spectrum and high coherence. Mid infrared laser have important value and application prospects in many fields, such as spectral analysis, remote sensing technology, space communication, military medical treatment. In this paper, the characteristics of mid-infrared supercontinuum with different distance, different incident pump power and different initial pulse width, are studied by split-step Fourier method (SSFM) based on nonlinear Schrodinger equation (NLSE).
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