scholarly journals 2 × 2 Matrices: Manifolds, Realizations, Applications

2021 ◽  
Vol 11 (16) ◽  
pp. 7479
Author(s):  
Kenan Uriostegui ◽  
Kurt Bernardo Wolf
Keyword(s):  
Angular Momentum ◽  
Light Propagation ◽  
Double Cover ◽  
Quantum Spin ◽  
Review Article ◽  
Matrix Group ◽  
Wave Optics ◽  
Linear Transformations ◽  
Wave Models ◽  
Classical And Quantum Mechanics

Both geometric and wave optical models, as well as classical and quantum mechanics, realize linear transformations with matrices; for plane optics, these are 2×2 and of unit determinant. Students and some researchers could assume that the structure of this matrix group is fairly evident and hardly interesting. However, the properties and applications even of this lowest 2×2 case are already unexpectedly rich. While in mechanics they cover classical angular momentum, quantum spin, and represent ‘2+1’ relativity, in optical models they lead from the geometrical description of light propagation in the paraxial regime to wave optics via linear canonical transforms requiring a more penetrating view of their manifold structure and multiple covers. The purpose of this review article is to highlight the topological space of 2×2 matrices as it applies to classical versus quantum and wave models, to underline how the latter requires the double cover of the former, thus using 2×2 matrices as an alternative viewpoint of the quantization process, beside the traditional characterization by commutation and non-commutations of position and momentum.

scholarly journals Recent advancements and perspectives on light management and high performance in perovskite light-emitting diodes

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shaoni Kar ◽  
Nur Fadilah Jamaludin ◽  
Natalia Yantara ◽  
Subodh G. Mhaisalkar ◽  
Wei Lin Leong
Keyword(s):  
High Performance ◽  
Light Propagation ◽  
Light Emission ◽  
Review Article ◽  
Rapid Progress ◽  
Light Emitting ◽  
Materials Engineering ◽  
Perovskite Materials ◽  
Light Management ◽  
Photon Recycling

Abstract Perovskite semiconductors have experienced meteoric rise in a variety of optoelectronic applications. With a strong foothold on photovoltaics, much focus now lies on their light emission applications. Rapid progress in materials engineering have led to the demonstration of external quantum efficiencies that surpass the previously established theoretical limits. However, there remains much scope to further optimize the light propagation inside the device stack through careful tailoring of the optical processes that take place at the bulk and interface levels. Photon recycling in the emitter material followed by efficient outcoupling can result in boosting external efficiencies up to 100%. In addition, the poor ambient and operational stability of these materials and devices restrict further commercialization efforts. With best operational lifetimes of only a few hours reported, there is a long way to go before perovskite LEDs can be perceived as reliable alternatives to more established technologies like organic or quantum dot-based LED devices. This review article starts with the discussions of the mechanism of luminescence in these perovskite materials and factors impacting it. It then looks at the possible routes to achieve efficient outcoupling through nanostructuring of the emitter and the substrate. Next, we analyse the instability issues of perovskite-based LEDs from a photophysical standpoint, taking into consideration the underlying phenomena pertaining to defects, and summarize recent advances in mitigating the same. Finally, we provide an outlook on the possible routes forward for the field and propose new avenues to maximally exploit the excellent light-emitting capabilities of this family of semiconductors.

scholarly journals The concept of creating thrust based on angular momentum change

2021 ◽  
Author(s):  
Sergei Kupreev
Keyword(s):  
Angular Momentum ◽  
Vacuum Chamber ◽  
Loop Quantum Gravity ◽  
Low Energy ◽  
Practical Implementation ◽  
Material Body ◽  
The World ◽  
Classical And Quantum Mechanics ◽  
Physical Principles ◽  
Kinetic Moment

Abstract The change in the kinetic moment of a material body is considered regarding to classical and quantum mechanics. The possibility of creating the propulsion system in terms of energy efficiency exceeding the photon engine has been theoretically proved. The proposed new principle of motion is based on the law of conservation of angular momentum and is fully consistent with the basic fundamental laws of physics. It is proposed to use the emission/absorption of streams of low-energy particles with spin in the direction perpendicular to the movement of the material body. The practical implementation of this idea is confirmed by the presence of promising approaches to solving the problem of quantizing gravity (string theory, loop quantum gravity, etc.) recognized by the world scientific community and by the successful results of experiments conducted by the authors with the motion of bodies in a vacuum chamber. The proposed idea, the examples and experiments has given grounds for the formation of new physical concepts of the speed, mass and inertia of bodies. The obtained results can be used in experiments to search for elementary particles with low energy, to explain a number of physics phenomena and to develop transport of objects based on new physical principles.

scholarly journals COSMOLOGICAL CONSTANT AND THE SPEED OF LIGHT

2001 ◽  
Vol 10 (01) ◽  
pp. 41-48 ◽  
Author(s):  
W. R. ESPÓSITO MIGUEL ◽  
J. G. PEREIRA
Keyword(s):  
Gravitational Field ◽  
Cosmological Constant ◽  
Electromagnetic Waves ◽  
Light Propagation ◽  
Wave Optics ◽  
Speed Of Light ◽  
Positive Cosmological Constant ◽  
Velocity Of Light ◽  
Refractive Medium ◽  
The Relationship

By exploring the relationship between the propagation of electromagnetic waves in a gravitational field and the light propagation in a refractive medium, it is shown that, in the presence of a positive cosmological constant, the velocity of light will be smaller than its special relativity value. Then, restricting again to the domain of validity of geometrical optics, the same result is obtained in the context of wave optics. It is argued that this phenomenon and the anisotropy in the velocity of light in a gravitational field are produced by the same mechanism.

Optics f2f

2018 ◽  
Author(s):  
Charles S. Adams ◽  
Ifan G. Hughes
Keyword(s):  
Vector Fields ◽  
Light Propagation ◽  
Angular Spectrum ◽  
Worked Examples ◽  
Building Blocks ◽  
Laser Beams ◽  
Wave Optics ◽  
Unified Approach ◽  
Fourier Methods ◽  
Spherical Waves

This book is primarily intended to be used in optics teaching from undergraduate to graduate level. It is assumed that an elementary course on optics has previously been studied, but all the key concepts of wave optics and light propagation are introduced where needed, and illustrated graphically. A recurring theme is that simple building blocks such as plane and spherical waves can be summed to construct useful solutions. Fourier methods and the angular-spectrum approach are used extensively, especially to provide a unified approach to Fraunhofer and Fresnel diffraction. Particular attention is paid to analysing topics in contemporary optics—propagation, dispersion, laser beams and waveguides, apodization, tightly focused vector fields, unconventional polarization states, and light–matter interactions. Throughout the text the principles are applied through worked examples and the book is copiously illustrated with more than 240 figures. The 200 end-of-chapter exercises offer further opportunities for testing the reader’s understanding.

Propagation stability in optical fibers: role of path memory and angular momentum

Nanophotonics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 209-224
Author(s):  
Zelin Ma ◽  
Siddharth Ramachandran
Keyword(s):  
Angular Momentum ◽  
Optical Fibers ◽  
Light Propagation ◽  
Spatial Dimension ◽  
Spatial Diversity ◽  
Multimode Fibers ◽  
Higher Order Modes ◽  
Subtle Effect ◽  
Spatial Modes

AbstractWith growing interest in the spatial dimension of light, multimode fibers, which support eigenmodes with unique spatial and polarization attributes, have experienced resurgent attention. Exploiting this spatial diversity often requires robust modes during propagation, which, in realistic fibers, experience perturbations such as bends and path redirections. By isolating the effects of different perturbations an optical fiber experiences, we study the fundamental characteristics that distinguish the propagation stability of different spatial modes. Fiber perturbations can be cast in terms of the angular momentum they impart on light. Hence, the angular momentum content of eigenmodes (including their polarization states) plays a crucial role in how different modes are affected by fiber perturbations. We show that, accounting for common fiber-deployment conditions, including the more subtle effect of light’s path memory arising from geometric Pancharatnam–Berry phases, circularly polarized orbital angular momentum modes are the most stable eigenbasis for light propagation in suitably designed fibers. Aided by this stability, we show a controllable, wavelength-agnostic means of tailoring light’s phase due to its geometric phase arising from path memory effects. We expect that these findings will help inform the optimal modal basis to use in the variety of applications that envisage using higher-order modes of optical fibers.

scholarly journals Analogies between optical and quantum mechanical angular momentum

2017 ◽  
Vol 375 (2087) ◽  
pp. 20150443 ◽  
Author(s):  
Gerard Nienhuis
Keyword(s):  
Wave Function ◽  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Quantum Particle ◽  
Three Dimensional ◽  
Propagation Direction ◽  
Linear Operators ◽  
Quantum Mechanical ◽  
Wave Optics ◽  
Quantum Harmonic Oscillator

The insight that a beam of light can carry orbital angular momentum (AM) in its propagation direction came up in 1992 as a surprise. Nevertheless, the existence of momentum and AM of an electromagnetic field has been well known since the days of Maxwell. We compare the expressions for densities of AM in general three-dimensional modes and in paraxial modes. Despite their classical nature, these expressions have a suggestive quantum mechanical appearance, in terms of linear operators acting on mode functions. In addition, paraxial wave optics has several analogies with real quantum mechanics, both with the wave function of a free quantum particle and with a quantum harmonic oscillator. We discuss how these analogies can be applied. This article is part of the themed issue ‘Optical orbital angular momentum’.

scholarly journals Scattering of Light from the Systemic Circulatory System

Diagnostics ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1026
Author(s):  
Sidra Batool ◽  
Mehwish Nisar ◽  
Fabio Mangini ◽  
Fabrizio Frezza ◽  
Eugenio Fazio
Keyword(s):  
Optical Properties ◽  
Light Propagation ◽  
Circulatory System ◽  
Biomedical Optics ◽  
Review Article ◽  
Basic Component ◽  
Human Tissues ◽  
X Rays ◽  
Factors Of Influence ◽  
Theoretical Scattering

There are many factors of methodological origin that influence the measurement of optical properties of the entire circulatory system which consists of blood as the basic component. The basic idea of this review article is to provide the optical properties of the circulatory system with all those factors of influence that have been employed in biomedical optics for different applications. We begin with the available optical properties, i.e., absorption, scattering and, reduced scattering coefficient, in general for any tissue inside the human body and prominent scattering theories (e.g., light, X-rays, neutrons) that are helpful in this regard. We have reviewed and compiled already available formulas and their respective available data for different human tissues for these optical properties. Then we have descended to the blood composition and to different scattering techniques available in the literature to study scattering and light propagation inside blood. We have reviewed both computational and theoretical scattering techniques.

scholarly journals The concept of creating thrust based on angular momentum change

2021 ◽  
Author(s):  
Sergei Kupreev ◽  
Yury Razoumny
Keyword(s):  
Angular Momentum ◽  
Vacuum Chamber ◽  
Loop Quantum Gravity ◽  
Low Energy ◽  
Radiation Absorption ◽  
Practical Implementation ◽  
Material Body ◽  
Classical And Quantum Mechanics ◽  
Physical Principles ◽  
Kinetic Moment

Abstract The change in the kinetic moment of a material body is considered regarding to classical and quantum mechanics. The possibility of creating the propulsion system in terms of energy efficiency exceeding the photon engine has been theoretically proved. The proposed new principle of motion is based on the law of conservation of angular momentum and is fully consistent with the basic fundamental laws of physics. It is proposed to use the radiation/absorption of streams of low-energy particles with spin in the direction perpendicular to the movement of the material body. The practical implementation of this idea is confirmed by the presence of promising approaches to solving the problem of quantizing gravity (string theory, loop quantum gravity, etc.) recognized by the world scientific community and by the successful results of experiments conducted by the authors with the motion of bodies in a vacuum chamber. The proposed idea, the examples and experiments has given grounds for the formation of new physical concepts of the speed, mass and inertia of bodies. The obtained results can be used in experiments to search for elementary particles with low energy, to explain a number of physics phenomena and to develop transport of objects based on new physical principles.

scholarly journals The concept of creating thrust based on angular momentum change

2021 ◽  
Author(s):  
Sergei Kupreev ◽  
Yury Razoumny
Keyword(s):  
Angular Momentum ◽  
Vacuum Chamber ◽  
Loop Quantum Gravity ◽  
Low Energy ◽  
Practical Implementation ◽  
Material Body ◽  
The World ◽  
Classical And Quantum Mechanics ◽  
Physical Principles ◽  
Kinetic Moment

Abstract The change in the kinetic moment of a material body is considered regarding to classical and quantum mechanics. The possibility of creating the propulsion system in terms of energy efficiency exceeding the photon engine has been theoretically proved. The proposed new principle of motion is based on the law of conservation of angular momentum and is fully consistent with the basic fundamental laws of physics. It is proposed to use the emission/absorption of streams of low-energy particles with spin in the direction perpendicular to the movement of the material body. The practical implementation of this idea is confirmed by the presence of promising approaches to solving the problem of quantizing gravity (string theory, loop quantum gravity, etc.) recognized by the world scientific community and by the successful results of experiments conducted by the authors with the motion of bodies in a vacuum chamber. The proposed idea, the examples and experiments has given grounds for the formation of new physical concepts of the speed, mass and inertia of bodies. The obtained results can be used in experiments to search for elementary particles with low energy, to explain a number of physics phenomena and to develop transport of objects based on new physical principles.

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