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Geometrical optics (GO) is often used to model wave propagation in weakly inhomogeneous media and quantum-particle motion in the semiclassical limit. However, GO predicts spurious singularities of the wavefield near reflection points and,…

Optics · Physics 2020-09-10 N. A. Lopez , I. Y. Dodin

Ray optics is an intuitive and computationally efficient model for wave propagation through nonuniform media. However, the underlying geometrical-optics (GO) approximation of ray optics breaks down at caustics, erroneously predicting the…

Optics · Physics 2022-10-10 Nicolas A. Lopez

The optimization of radiofrequency-wave (RF) systems for fusion experiments is often performed using ray-tracing codes, which rely on the geometrical-optics (GO) approximation. However, GO fails at caustics such as cutoffs and focal points,…

Plasma Physics · Physics 2022-05-24 N. A. Lopez , I. Y. Dodin

Metaplectic geometrical optics (MGO) is a recently developed ray-tracing framework to accurately compute the wavefield behavior near a caustic (turning point or focal point), where traditional ray-tracing breaks down. However, MGO has thus…

Plasma Physics · Physics 2024-08-22 N. A. Lopez , R. Højlund , M. G. Senstius

The design and optimization of radiofrequency-wave systems for fusion applications is often performed using ray-tracing codes, which rely on the geometrical-optics (GO) approximation. However, GO fails at wave cutoffs and caustics. To…

Computational Physics · Physics 2021-08-18 Sean M. Donnelly , Nicolas A. Lopez , I. Y. Dodin

Geometrical optics (GO) is widely used in studies of electromagnetic materials because of its ease of use compared to full-wave numerical simulations. Exact solutions for waves can, however, differ significantly from the GO approximation.…

Optics · Physics 2015-06-18 T. G. Philbin

Geometrical optics (GO) is widely used for reduced modeling of waves in plasmas but fails near reflection points, where it predicts a spurious singularity of the wave amplitude. We show how to avoid this singularity by adopting a different…

The WKB approximation of geometrical optics is widely used in plasma physics, quantum mechanics and reduced wave modeling in general. However, it is well-known that the approximation breaks down at focal and turning points. In this work we…

Plasma Physics · Physics 2024-08-29 Rune Højlund Marholt , Mads Givskov Senstius , Stefan Kragh Nielsen

The paper presents an ab initio account of the paraxial complex geometrical optics (CGO) in application to a scalar Gaussian beam propagation and diffraction in a 3D smoothly inhomogeneous medium. The paraxial CGO deals with quadratic…

Optics · Physics 2009-11-11 P. Berczynski , K. Yu. Bliokh , Yu. A. Kravtsov , A. Stateczny

We consider the scattering of light in participating media composed of sparsely and randomly distributed discrete particles. The particle size is expected to range from the scale of the wavelength to the scale several orders of magnitude…

Graphics · Computer Science 2021-02-25 Jie Guo , Bingyang Hu , Yanjun Chen , Yuanqi Li , Yanwen Guo , Ling-Qi Yan

Optical tweezers have found widespread application in many fields, from physics to biology. Here, we explain in detail how optical forces and torques can be described within the geometrical optics approximation and we show that this…

Optics · Physics 2015-06-18 Agnese Callegari , Mite Mijalkov , A. Burak Gököz , Giovanni Volpe

Waves play an essential role in many aspects of plasma science, such as plasma manipulation and diagnostics. Due to the complexity of the governing equations, approximate models are often necessary to describe wave dynamics. In this…

Plasma Physics · Physics 2017-08-21 D. E. Ruiz

This paper explores the topologies of caustics observed in instruments that employ charged particles, such as electron and ion microscopes. These geometrical figures are studied here using catastrophe theory. The application of this…

Geometric-optical illusions (GOI) are a subclass of a vast variety of visual illusions. A special class of GOIs originates from the superposition of a simple geometric figure ("target") with an array of non-intersecting curvilinear elements…

Neurons and Cognition · Quantitative Biology 2016-10-10 Werner Ehm , Jiri Wackermann

Nowadays the geometric approach in optics is often used to find out media parameters based on propagation paths of the rays because in this case it is a direct problem. However inverse problem in the framework of geometrical optics is…

Geometrical optical illusions have been object of many studies due to the possibility they offer to understand the behaviour of low-level visual processing. They consist in situations in which the perceived geometrical properties of an…

Computer Vision and Pattern Recognition · Computer Science 2016-12-06 B. Franceschiello , A. Sarti , G. Citti

We consider the possible effects of gravitational lensing by globular clusters on gravitational waves from asymmetric neutron stars in our galaxy. In the lensing of gravitational waves, the long wavelength, compared with the usual case of…

General Relativity and Quantum Cosmology · Physics 2016-11-15 Andrew J. Moylan , David E. McClelland , Susan M. Scott , Antony C. Searle , G. V. Bicknell

Lipschitz one-dimensional constrained global optimization (GO) problems where both the objective function and constraints can be multiextremal and non-differentiable are considered in this paper. Problems, where the constraints are verified…

Optimization and Control · Mathematics 2011-07-27 Yaroslav D. Sergeyev , Dmitri E. Kvasov , Falah M. H. Khalaf

Metasurfaces -- ultrathin structures composed of subwavelength optical elements -- have revolutionized light manipulation by enabling precise control over electromagnetic waves' amplitude, phase, polarization, and spectral properties.…

Optics · Physics 2024-11-15 Charles Roques-Carmes , Kai Wang , Yuanmu Yang , Arka Majumdar , Zin Lin

We present a geometric optics theory for the transport of quantum particles (or classical waves) in a chiral and dissipative periodic crystal subject to slowly varying perturbations in space and time. Taking account of some properties of…

Other Condensed Matter · Physics 2014-11-18 Chuanwei Zhang , Qian Niu
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