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The Quantum Properties of a Superposition of Vee Type Three-level Lasers
Issue:
Volume 9, Issue 4, July 2021
Pages:
64-69
Received:
26 May 2021
Accepted:
13 July 2021
Published:
22 July 2021
Abstract: The squeezing, and statistical properties of a superposed light beam produced by a lambda type three-level lasers configuration have been studied. We have determined the quadrature variances mean as well as variance photon number for cavity modes with the aid of the solutions of c-number Langevin equations associated with the normal order. We have carried out our analysis a light in a squeezing state can be produced by the system under consideration under the condition that the cavity decay constant is larger than the linear gain coefficient and the squeezing occurs in the minus-quadrature. Furthermore, we also obtain with the aid of the Q-functions and the density operator the superposition beam, and superposed light beams are determined in quadrature variance and mean photon number. The result shows that the mean photon number and the quadrature variance of the superposed light beam are the sum of the mean photon number and the quadrature variance of the constituent light beams.
Abstract: The squeezing, and statistical properties of a superposed light beam produced by a lambda type three-level lasers configuration have been studied. We have determined the quadrature variances mean as well as variance photon number for cavity modes with the aid of the solutions of c-number Langevin equations associated with the normal order. We have ...
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Plasma Surface Metallurgy of Materials Based on Double Glow Discharge Phenomenon
Zhong Xu,
Jun Huang,
Zaifeng Xu,
Xiaoping Liu,
Hongyan Wu
Issue:
Volume 9, Issue 4, July 2021
Pages:
70-87
Received:
13 July 2021
Accepted:
28 July 2021
Published:
4 August 2021
Abstract: Plasma Surface Metallurgy /Alloying is a kind of surface metallurgy/alloying to employ low temperature plasma produced by glow discharge to diffuse alloying elements into the surface of substrate material to form an alloy layer. It is different with ion nitriding technology, which is only applicable to the surface infiltration of non-metallic elements. “Double Glow Plasma Surface Metallurgy Technology”, also known as the “Xu-Tec Process” can utilize any chemical elements in the periodic table including solid metallic, gas non-metallic elements and their combination to realize plasma surface alloying, hence greatly expanded the field of surface alloying. Countless surface alloys with high hardness, wear resistance and corrosion resistance, such as high speed steels, nickel base alloys and burn resistant alloys have been produced on the surfaces of a variety of materials. This technology may greatly improve the surface properties of metal materials, comprehensively improve the quality of mechanical products, save a lot of precious alloy elements for human beings. Based on the plasma nitriding technology, the Xu-Tec Process has opened up a new material engineering field of “Plasma Surface Metallurgy”. This review article briefly presents the history of glow discharge and surface alloying, double glow discharge phenomenon, basic principle and current status of Double Glow Plasma Surface Metallurgy/Alloying. Industrial applications, advantages and future potential of the Xu-Tec process are also presented.
Abstract: Plasma Surface Metallurgy /Alloying is a kind of surface metallurgy/alloying to employ low temperature plasma produced by glow discharge to diffuse alloying elements into the surface of substrate material to form an alloy layer. It is different with ion nitriding technology, which is only applicable to the surface infiltration of non-metallic eleme...
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Independent Modulation of the Phase and Amplitude of Electromagnetic Waves Based on the Phase Change of VO2 and Mode Coupling
Tianrui Pan,
Yuan Pei,
Maosheng Wang,
Xiaojuan Xie,
Wanxia Huang
Issue:
Volume 9, Issue 4, July 2021
Pages:
88-93
Received:
11 July 2021
Accepted:
2 August 2021
Published:
12 August 2021
Abstract: Metasurfaces in a metal–semiconductor–metal configuration have been studied in multiple contexts, including perfect absorption and phase modulation. Nevertheless, limit progress has been achieved in independent phase modulation. To study further in this work, a metasurface composed of an Au film/ VO2 film/ Au patch array with square holes was proposed in this paper. Through simulating and analysing the optical properties, simulated results indicated that an extremely switchable function can be realized by modulating the phase transition of VO2, when VO2 was in the metal (semiconductor) phase, the whole structure represented as ON (OFF) state. Additionally, the efficient modulation depth is approximately 99.6% for the y-polarization at a wavelength of 2.019 µm. What’s more, by modulating symmetry-breaking of the structure or polarization, an extreme reflection phase change can been applied. As for the former, by adjusting the asymmetry degreed, the reflection phase can change from less than 180° to nearly 360°, and for the latter, the adjustment in polarization resulted in a phase change of nearly 180° for the x-polarization and nearly 360° for the y-polarization. While the amplitude remained almost constant at the corresponding wavelength. That is to say, an independent regulation of amplitude and phase was accomplished. And a two-mode one-port temporal coupled mode theory supported by full-wave simulations can explain the underlying physics of the designed independent phase modulation. The research findings mentioned above established the possibility for plasmonic integration as well as the design of multi-functional devices such as gradient metasurfaces and temperature-controlled switches.
Abstract: Metasurfaces in a metal–semiconductor–metal configuration have been studied in multiple contexts, including perfect absorption and phase modulation. Nevertheless, limit progress has been achieved in independent phase modulation. To study further in this work, a metasurface composed of an Au film/ VO2 film/ Au patch array with square holes was propo...
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Excel Files for Teaching About Wave Fronts and Rays for a Wave Moving in Media with Changing Index of Refraction
Issue:
Volume 9, Issue 4, July 2021
Pages:
94-101
Received:
10 August 2021
Accepted:
20 August 2021
Published:
27 August 2021
Abstract: In teaching about waves the students are learning how to find the refracted rays by using wave fronts or finding the wave fronts by using the rays. The usual teaching is based on models where the speed of the wave is constant in one medium and changes abruptly as the wave passes from one medium to another. This paper deals with ways of calculation the wave fronts and the rays for the case of a continuous changing of the index of refraction. For this purpose, Fermat’s principle is applied for multiple layers of very small thickness. Two models are presented for the speed of the waves: A model on which the wave speed depends on the square root of the depth of penetration of the wave and the other model, where the speed depends on a linear dependence. In both cases it is found that as the wave progresses it is “totally reflected”. In the case of the “square root dependence” the solution is a kind of cycloid which shows this behavior. In the linear case it is found that there is a moment where the wave is reflected, which is found by the maximum of a quantity “Z”. By using this quantity, the coordinates x and y can be calculated. As an application the refraction of the light in the atmosphere is calculated, where the dependence of the distance from the center of the earth is calculated and again the 2 models are applied. In this case the “square root” model gives a stronger deviation from the linear model. This helps the student to understand the change on the perceived position of the celestial bodies.
Abstract: In teaching about waves the students are learning how to find the refracted rays by using wave fronts or finding the wave fronts by using the rays. The usual teaching is based on models where the speed of the wave is constant in one medium and changes abruptly as the wave passes from one medium to another. This paper deals with ways of calculation ...
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