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[IEEE 2018 IEEE International Conference on Electrical Engineering and Photonics (EExPolytech) - Saint Petersburg, Russia (2018.10.22-2018.10.23)] 2018 IEEE International Conference on Electrical Engineering and Photonics (EExPolytech) - Monitoring of Flowing Media State by Refraction Phenomenon
摘要： A paper the refraction phenomenon for condition control of flowing media is considered. The peculiarity of flowing liquid condition control by displacement of the light-shadow boundary are determined. The results of experimental investigations are presented.
关键词： refraction,refractive index,full internal reflection,stream of fluid flow
更新于2025-09-23 15:23:52
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Contact Lenses || Optics and Lens Design
摘要： Some aspects of contact lens design and optics are rarely applied nowadays, as they are less relevant to modern practice, but readers may still need to refer to them. They are available at: https://expertconsult.inkling.com/, whereas the more relevant topics are included here. The appendix, available at: https://expertconsult.inkling.com/, also describes various equations that are used in contact lens work, while the online resources include programs relating to both the optics and to lens design. There are two main aspects to be considered when dealing with the optics of contact lenses: the effects on the wearer of the optical differences from spectacles and the necessity for the practitioner to understand the components which affect the back vertex power (BVP) of the contact-lens/liquid*-lens system. There is some overlap of these two aspects, but for the sake of convenience they are discussed separately in the first two sections of the chapter. In the second section a set of approximate rules is included, the use of which should permit practitioners to make quick and reasonably accurate estimates of changes in power caused by altering certain lens parameters. The Cartesian sign convention2 is used throughout. For further understanding of the basic principles involved, readers are referred to the works of Bennett (1985), Tunnacliffe (1993), Freeman and Hull (2003), Douthwaite (2006) and Rabbetts (2007).
关键词： Lens Design,Astigmatism,Optics,Bifocal Contact Lenses,Power Variations,Contact Lenses,Ocular Refraction,Aberrations,Spectacles
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE 2nd International Conference on Dielectrics (ICD) - Budapest (2018.7.1-2018.7.5)] 2018 IEEE 2nd International Conference on Dielectrics (ICD) - Method for Calculating Electronic Polarizability of Water Molecules and Refractive Index
摘要： A method for calculating the electronic polarizability of water molecules is proposed. In the approximation of this method, the electronic components of the hyperpolarizability of the first and second order for the water molecule are determined.
关键词： water molecule,electron polarizability,refractive index,hyperpolarizability,electronic polarizability,molar refraction
更新于2025-09-23 15:22:29
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Terahertz Differential Computed Tomography: a Relevant Nondestructive Inspection Application
摘要： In recent years, tremendous advances have been made in the choice of materials used in the industry. With weight reduction as the goal, composite and polymer materials are more and more popular but they are almost transparent to X-ray. Because of this, interest has grown in other wavelengths like terahertz (THz). Due to a difference in how X-ray and THz propagate, X-ray CT algorithms cannot be directly used. For example, THz induces refraction making the reconstruction problem nonlinear. In this paper, we present a new algorithm which complies with beam profile intensities, refraction, and reflection. It is based on linearizing the reconstruction process around a computer-aided design (CAD) model of the object to be reconstructed. The method we propose computes the deviation between the object and this model.
关键词： Terahertz computed tomography,Inverse problem,Nondestructive testing,Modeling,Monte Carlo,Refraction,Nonlinear problem,Projection simulation
更新于2025-09-23 15:22:29
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Four-Wave Mixing in Metamaterials
摘要： Interaction of four counterpropagating waves in a cubic medium being “left” for the signal wave is considered in the constant-intensity approximation. Analytical expression for the signal wave intensity is derived for the general case of four-wave interaction in a metamaterial. The influence of different parameters on the signal wave amplification coefficient, efficiency of conversion into the signal wave, and the reflection coefficient of the mirror whose role is played by the metamaterial is analyzed. It has been obtained for the first time that the determining role in the backward signal wave amplification is played by the total length of the metamaterial and the intensities of all three forward waves. An analysis has shown that the optimal thickness of the metamaterial depends not only on the phase mismatch and the strong coherent pump field intensity, as in the constant-field approximation, but also on the intensity of the weak wave at the frequency ω2. It has been demonstrated for the first time that the efficiency of frequency conversion in metamaterials depends on the total metamaterial length, input intensities of all four interacting waves, phase mismatch, and losses in the medium. It is established that the maxima of the reflection coefficient of the metamaterial depend on the total metamaterial length and the intensities of all three forward waves.
关键词： metamaterial,negative refraction,four-wave interaction,constant-intensity approximation
更新于2025-09-23 15:22:29
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Influence of the level of monovision on visual outcome with an extended range of vision intraocular lens
摘要： Purpose: The purpose of this study was to evaluate the influence of different levels of monovision on the clinical outcomes achieved with an extended range of vision (ERV) intraocular lens (IOL). Patients and methods: Subanalysis of 411 patients from the multicenter CONCERTO study aimed at evaluating the outcomes after bilateral implantation of the Tecnis Symfony IOL. Visual acuity, spectacle independence, photic phenomena incidence, and patient satisfaction outcomes were evaluated in six groups defined according to the level of monovision: 0.0 D (75 patients; group 1), 0,x#0.25 D (148 patients; group 2), 0.25,x #0.5 D (90 patients; group 3), 0.5,x#0.75 D (52 patients; group 4), 0.75,x#1.0 D (27 patients; group 5), and .1.0 D (19 patients; group 6). Results: Mean binocular uncorrected distance visual acuity (decimal) ranged from 0.90±0.17 in group 6 to 0.97±0.20 in group 2. Mean binocular uncorrected intermediate visual acuity (decimal) ranged from 0.77±0.25 in group 2 to 0.94±0.30 in group 4. Mean binocular uncorrected near visual acuity ranged from 0.64±0.23 in group 2 to 0.79±0.26 in group 6. The level of spectacle independence was high, with the highest value for near vision in group 6 (94.7%). Less patients reported halos (6.7%) in group 1, whereas only 3.8% of patients in group 4 reported disturbing glare symptoms. For near vision, the highest patient satisfaction was achieved in groups 4, 5, and 6. A total of 96.7% (group 3) and 96.2% (group 4) of patients would recommend the same procedure to their friends and family and would choose the same lens again. Conclusion: Mini-monovision of around 0.75 D after implantation of the Tecnis Symfony IOL provides a complete visual rehabilitation with minimal photic phenomena and high levels of patient satisfaction.
关键词： Tecnis Symfony IOL,CONCERTO study,visual acuity,residual refraction,targeted monovision
更新于2025-09-23 15:22:29
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On Geometric Optics over a Spherical Earth With an Exponential Refraction Index
摘要： The ray based method of geometrical optics can be used for wave propagation a over spherical earth with good results. A previous such a method also includes an exponential refraction index. This method gives good results for large terminal heights and distances, but for small distances, it has some shortcomings. In this paper, an improvement is proposed which remove these shortcomings. Also, as the method depends on numerical procedures, some improved numerical calculations are put forward.
关键词： refraction,geometrical optics,Electromagnetic propagation
更新于2025-09-23 15:21:21
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Terahertz shifted Fano resonance-induced plasmon-soliton in graphene-plasmonic waveguide with magnetic impurities
摘要： Fano resonance is a quantum effect particularly useful for determining the optical spectra of semiconductor heterostructures and radiation enhancement of semiconductor-based devices. We deal with the nonlinear amplitude equation to find the nonlinear plasmon modes and breather solutions in a magnetic impurities-added graphene-plasmonic waveguide at near and mid-IR frequency range. The results show that the coupling degree between the plamon modes and breather solutions in order to form plasmon-solitons is intensely influenced by the effective nonlinear refraction assigned to the waveguide and also by the Fermi energy; tunable plasmon-solitons can be formed with a lowly required bias voltage. We also deduce that the stable plasmon-solitons and subsequently the most condensed radiative feature with the largest effective propagation length can be obtained at interband transition edge if the resonance of the effective nonlinear refraction is of Fano type. The reason is inferred as the presence of a reversible mechanism caused by the optical doping which in turn bears a successive competition between the diffraction and nonlinearity. Accordingly, we indicate that the Fano resonance- induced plasmon-soliton modes supported by the Co-added graphene-plasmonic waveguide experience a frequency shift up to Δω ? 60 THz in contrast to the plasmon-soliton modes in the pristine graphene-based waveguide. This in turn, proposes a novel technique for the spectroscopy of magnetic impurities-added graphene-dielectric heterostructures. On the other hand, very sensi- tive modulation of the nonlinear response tunable with a low Fermi energy as presented in this study can delineate modern schemes for the next generation graphene plasmonic devices including the nanoscale radiation sources, modulators, biosensors and couplers.
关键词： Fano resonance,Graphene plasmonic waveguide,Plasmon-soliton,Nonlinear refraction,Breather solution,Magnetic impurities
更新于2025-09-23 15:19:57
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A Fast Analysis Method for Blue-Green Laser Transmission through the Sea Surface
摘要： The fast estimation of blue-green laser transmission characteristics through the fluctuating sea surface, such as refraction angles and transmittance, is very important to correct operating parameters, detection depth and anti-detection warning in airborne Light Detection and Ranging (LiDAR) applications. However, the geometry of the sea surface is changed by complex environment factors, such as wind and wave, which significantly affect the rapid acquisition of the blue-green laser transmission characteristics. To address this problem, a fast analysis method is provided to rapidly compute the blue-green laser transmittance and refraction angles through the fluctuating sea surface driven by different wind directions and speeds. In the method, a three-dimensional wave model driven by the wind was built to describe the wave spatial distribution varying with time. Using the wave model, the propagation path of the scanning laser footprint was analyzed using the proposed meshing method, thus the transmittance and refraction angles of the optical path can be fast obtained by using parallel computing. The simulation results imply that the proposed method can reduce the time consumption by 70% compared with the traditional analytical method with sequential computing. This paper provides some statistical laws of refraction angles and transmittance through the fluctuating sea surface under different wind conditions, which may serve as a basic for fast computation of airborne LiDAR transmission characteristics in complex environments.
关键词： blue-green laser,sea surface,refraction angles,wave model,transmission characteristics,transmittance,airborne LiDAR
更新于2025-09-23 15:19:57
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Refraction and reflection from the interface of anisotropic materials
摘要： In this paper the reflection and refraction of the electromagnetic waves from the planar interface of an anisotropic medium are investigated. The considered anisotropic medium is a uniaxial material whose optical axis lies in the incident plane and makes an arbitrary angle with the normal to the interface. It is shown that the directions of the wave and Poynting vectors of the transmitted wave depend on the incident angle and the orientation of the optical axis of the uniaxial material. Also, the situation that the negative refraction can happen for such media is obtained. In addition, the dependence of the Brewster angle to the orientation of the optical axis of the uniaxial material is considered. More interestingly, it is shown that there is a situation for which the wave and Poynting vectors of the transmitted transverse magnetic wave are parallel.
关键词： Poynting vector,Reflection,Anisotropic material,Refraction,Wave vector,Negative refraction
更新于2025-09-19 17:15:36