scholarly journals An energy conservative hp-scheme for light propagation using Liouville’s equation for geometrical optics

2020 ◽  
Vol 238 ◽  
pp. 02005
Author(s):  
Robert A.M. van Gestel ◽  
Martijn J.H. Anthonissen ◽  
Jan H.M. ten Thije Boonkkamp ◽  
Wilbert L. IJzerman
Keyword(s):  
Optical System ◽  
Light Propagation ◽  
Energy Propagation ◽  
Conservation Of Energy ◽  
Adaptive Scheme ◽  
Propagation Of Light ◽  
Light Rays ◽  
Liouville’S Equation ◽  
Full Domain ◽  
Space Description

In this contribution an alternative method to standard forward ray-tracing is briefly outlined. The method is based on a phase-space description of light propagating through an optical system. The propagation of light rays are governed by Hamilton’s equations. Conservation of energy and étendue for a beam of light, allow us to derive a Liouville’s equation for the energy propagation through an optical system. Liouville’s equation is solved numerically using an hp-adaptive scheme, which for a smooth refractive index field is energy conservative. A proper treatment of optical interfaces ensures that the scheme is energy conservative over the full domain.

scholarly journals Light propagation and optical scalars in torsion theories of gravity

2019 ◽  
Vol 34 (04) ◽  
pp. 1950029
Author(s):  
Siamak Akhshabi
Keyword(s):  
Gravitational Lensing ◽  
Light Propagation ◽  
Raychaudhuri Equation ◽  
Angular Diameter Distance ◽  
Propagation Of Light ◽  
Light Rays ◽  
Theories Of Gravity ◽  
Torsion Theories ◽  
Basic Equations ◽  
Gauge Theory Of Gravity

We investigate the propagation of light rays and evolution of optical scalars in gauge theories of gravity where torsion is present. Recently, the modified Raychaudhuri equation in the presence of torsion has been derived. We use this result to derive the basic equations of geometric optics for several different interesting solutions of the Poincaré gauge theory of gravity. The results show that the focusing effects for neighboring light rays will be different than general relativity. This in turn has practical consequences in the study of gravitational lensing effects and also in determining the angular diameter distance for cosmological objects.

scholarly journals Metamaterials mimic the black holes: the effects of charge and rotation on the optical properties

2020 ◽  
Vol 2020 (7) ◽  
Author(s):  
S H Hendi ◽  
Z S Taghadomi ◽  
A Ghasempour Ardakani
Keyword(s):  
Black Holes ◽  
Optical Properties ◽  
Light Propagation ◽  
Transformation Optics ◽  
Two Dimensional ◽  
Propagation Of Light ◽  
Analogue Gravity ◽  
Light Rays ◽  
Optical Limit ◽  
Dimensional Simulation

Abstract Motivated by the investigation of a black hole’s properties in the lab, some interesting subjects such as analogue gravity and transformation optics are generated. In this paper, we look for analogies between the geometry of a gravitating system and the optical medium. In addition, we recognize that appropriate two-dimensional metamaterials can be used to mimic the propagation of light in the curved spacetimes and behave like black holes which are incident with light rays in the equatorial plane. The resemblance of metamaterials with Kerr and Reissner–Nordström spacetimes is studied. Finally, we compare the results of two-dimensional simulation for light propagation in the corresponding two-dimensional metamaterials with those obtained from the geometrical optical limit.

scholarly journals Вычислительный эксперимент по моделированию распространения света в волокнистой профилированной структуре

2020 ◽  
pp. 50-57
Author(s):  
V. V. Savchenko ◽  
M. A. Savchenko
Keyword(s):  
Ray Tracing ◽  
Light Propagation ◽  
Short Note ◽  
Fiber Structure ◽  
Propagation Of Light ◽  
Light Rays ◽  
Tracing Algorithm ◽  
The Given ◽  
System Characteristics ◽  
Fiber Sample

Many studies show that profiled structures are the source of attaining desired system characteristics in industrial or other applications. In this short note, we continue considering proposed recently by us the profiled structure such as a beach umbrella based on the principles of origami design. To demonstrate the optical properties of the given model, a developed recursive ray tracing algorithm is used to simulate the propagation of light rays through the modelled paper fiber sample. In this paper, modeling light propagation through a porous structure using ray tracing technique is presented and results of modeling light propagation in a profiled structure with respect to simulated light propagation in fiber structure are discussed. Во многих работах указывается, что использование профилированных структур позволяет получить характеристики материала, необходимые для его применения в промышленности и других областях. В этой небольшой статье мы продолжаем рассматривать предложенную нами недавно профилированную структуру в виде пляжного зонта, основанную на принципах дизайна оригами. Для демонстрации оптических свойств данной модели используется разработанный алгоритм рекурсивной трассировки лучей для моделирования распространения световых лучей через смоделированный образец бумажного волокна. В этой статье представлено моделирование распространения света через пористую структуру с использованием техники трассировки лучей, а также обсуждаются результаты моделирования распространения света в профилированной структуре в сравнении с моделированным распространением света в волокнистой структуре.

Types of refractive errors and methods for their diagnosis

2020 ◽  
pp. 30-36
Author(s):  
Olga Lemzyakova
Keyword(s):  
Optical System ◽  
Contact Lenses ◽  
Vision Impairment ◽  
Refractive Errors ◽  
Vision Correction ◽  
Light Rays ◽  
Different Types ◽  
Almost All ◽  
Degrees Of Severity ◽  
The Brain

Refraction of the eye means its ability to bend (refract) light in its own optical system. In a normal state, which is called emmetropia, light rays passing through the optical system of the eye focus on the retina, from where the impulse is transmitted to the visual cortex of the brain and is analyzed there. A person sees equally well both in the distance and near in this situation. However, very often, refractive errors develop as a result of various types of influences. Myopia, or short-sightedness, occurs when the light rays are focused in front of the retina as a result of passing through the optical system of the eye. In this case, a person will clearly distinguish close objects and have difficulties in seeing distant objects. On the opposite side is development of farsightedness (hypermetropia), in which the focusing of light rays occurs behind the retina — such a person sees distant objects clearly, but outlines of closer objects are out of focus. Near vision impairment in old age is a natural process called presbyopia, it develops due to the lens thickening. Both myopia and hypermetropia can have different degrees of severity. The variant, when different refractive errors are observed in different eyes, is called anisometropia. In the same case, if different types of refraction are observed in the same eye, it is astigmatism, and most often it is a congenital pathology. Almost all of the above mentioned refractive errors require correction with spectacles or use of contact lenses. Recently, people are increasingly resorting to the methods of surgical vision correction.

scholarly journals Certain Mathematical Instruments for Graphically Indicating the Direction of Refracted and Reflected Light Rays

1906 ◽  
Vol 25 (2) ◽  
pp. 806-812
Author(s):  
J.R. Milne
Keyword(s):  
Optical System ◽  
The Other ◽  
Reflected Light ◽  
Light Rays ◽  
Image Position

The refraction equation sin i == μ sin r, though simple in itself, is apt to give rise, in problems connected with refraction, to formulæ too involved for arithmetical computation. In such cases it may be necessary to trace the course through the optical system in question of a certain number of arbitrarily chosen rays, and thence to find the course of the other rays by interpolation. Thelinkage about to be described affords a rapid and accurate means of determining the paths of the rays through any optical system.

scholarly journals Light Propagation through Nanophotonics Wormholes

Universe ◽  
2018 ◽  
Vol 4 (12) ◽  
pp. 137 ◽  
Author(s):  
Carlos Sabín
Keyword(s):  
Light Propagation ◽  
State Of The Art ◽  
Curved Space ◽  
Traversable Wormhole ◽  
Propagation Of Light ◽  
Phase And Group Velocities ◽  
Spatial Shape ◽  
Group Velocities

We consider the propagation of light along a 3D nanophotonic structure with the spatial shape of a spacetime containing a traversable wormhole. We show that waves experience significant changes of phase and group velocities when propagating along this curved space. This experiment can be realized with state-of-the-art nanophotonics technology.

A genesis of special relativity

2015 ◽  
Vol 24 (10) ◽  
pp. 1530024
Author(s):  
Valérie Messager ◽  
Christophe Letellier
Keyword(s):  
Special Relativity ◽  
19Th Century ◽  
Maxwell Equations ◽  
Light Propagation ◽  
Principle Of Relativity ◽  
Light Rays ◽  
Optical Phenomena ◽  
Light Particles ◽  
The 19Th Century ◽  
The Waves

The genesis of special relativity is intimately related to the development of the theory of light propagation. When optical phenomena were described, there are typically two kinds of theories: (i) One based on light rays and light particles and (ii) one considering the light as waves. When diffraction and refraction were experimentally discovered, light propagation became more often described in terms of waves. Nevertheless, when attempts were made to explain how light was propagated, it was nearly always in terms of a corpuscular theory combined with an ether, a subtle medium supporting the waves. Consequently, most of the theories from Newton's to those developed in the 19th century were dual and required the existence of an ether. We therefore used the ether as our Ariadne thread for explaining how the principle of relativity became generalized to the so-called Maxwell equations around the 1900's. Our aim is more to describe how the successive ideas were developed and interconnected than framing the context in which these ideas arose.

scholarly journals Deep Learning for Computational Mode Decomposition in Optical Fibers

2020 ◽  
Vol 10 (4) ◽  
pp. 1367
Author(s):  
Stefan Rothe ◽  
Qian Zhang ◽  
Nektarios Koukourakis ◽  
Jürgen W. Czarske
Keyword(s):  
Neural Network ◽  
Optical Fibers ◽  
High Performance ◽  
Deep Neural Network ◽  
Light Propagation ◽  
Training Data ◽  
Steady Increase ◽  
Cyberphysical Systems ◽  
Multimode Fibers ◽  
Propagation Of Light

Multimode fibers are regarded as the key technology for the steady increase in data rates in optical communication. However, light propagation in multimode fibers is complex and can lead to distortions in the transmission of information. Therefore, strategies to control the propagation of light should be developed. These strategies include the measurement of the amplitude and phase of the light field after propagation through the fiber. This is usually done with holographic approaches. In this paper, we discuss the use of a deep neural network to determine the amplitude and phase information from simple intensity-only camera images. A new type of training was developed, which is much more robust and precise than conventional training data designs. We show that the performance of the deep neural network is comparable to digital holography, but requires significantly smaller efforts. The fast characterization of multimode fibers is particularly suitable for high-performance applications like cyberphysical systems in the internet of things.

SYMPLECTIC STRUCTURE ON THE SET OF GEODESICS OF A RIEMANNIAN MANIFOLD

1991 ◽  
Vol 06 (03) ◽  
pp. 431-444 ◽  
Author(s):  
JOSÉ F. CARIÑENA ◽  
CARLOS LÓPEZ
Keyword(s):  
Riemannian Manifold ◽  
Optical System ◽  
Symplectic Structure ◽  
Light Rays

A natural symplectic structure is defined on the set of oriented geodesics of a Riemannian or pseudo-Riemannian manifold. Particular examples—the set of straightlines of a plane and the set of light rays of an optical system—are developed.

scholarly journals Representations of rectilinear light propagation in the thinking of 12-13 year olds: A transformative teaching intervention

2021 ◽  
Vol 10 (2) ◽  
pp. 191-199
Author(s):  
Alyona Grigorovitch
Keyword(s):  
Statistical Analysis ◽  
Light Propagation ◽  
Mental Representations ◽  
Sampling Technique ◽  
Traditional School ◽  
Transformative Teaching ◽  
Effective Interventions ◽  
Propagation Of Light ◽  
School Teaching ◽  
Quasi Experimental

This research investigates the transformation of the seventh-grade students' mental representations of the rectilinear propagation of light. The researcher employed the quasi-experimental method on two groups of students aged 12-13 years. The survey involved 102 students who were divided into two equal groups determined by the stratified sampling technique. The first group participated in a didactic intervention based on the students' representations. The second group of students participated in a traditional school teaching. The Mann–Whitney U test was utilized for calculating the significance of the data. The statistical analysis showed that the pretest and the posttest progress was statistically significant for the first group. It resulted in the mental constitution of a representation that is compatible with the scientific model.The research results allow the design of effective interventions for the teaching of light propagation and geometric optics in general.

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