China
Africa
Explore chapters and articles related to this topic
Review of Essential Basics
Published in Bethe A. Scalettar, James R. Abney, Cyan Cowap, Introductory Biomedical Imaging, 2022
Bethe A. Scalettar, James R. Abney, Cyan Cowap
The angles, θ1 and θ2, define the direction of incident and transmitted rays with respect to the normal to the interface, as shown. Important conceptual consequences of the law of refraction include the fact that light bends toward the normal when incident from a medium of lower refractive index onto a medium of higher refractive index, and away from the normal when incident from a medium of higher refractive index onto a medium of lower refractive index. In contrast, the Law of Reflection states that the reflected and incident rays make equal angles with respect to the normal (Fig. 2.5a).
Telescopes for Inner Space: Fiber Optics and Endoscopes
Published in Suzanne Amador Kane, Boris A. Gelman, Introduction to Physics in Modern Medicine, 2020
Suzanne Amador Kane, Boris A. Gelman
These results for reflection and refraction allow the use of lenses and mirrors to shape the pathway of light and form magnified images. The operation of mirrors is solely determined by the reflection rule and the shape of the mirror. The mirror's optics are determined by drawing sample rays of light and tracing their pathways upon reflection, using the rule that the reflected ray's angle is equal to that of the original ray. Lenses are specially ground pieces of glass, plastic, or quartz (Figure 2.8a); their operation can be understood by considering the way they refract the light that falls on them. Lenses are constructed to utilize this refraction to focus rays. This is shown in Figure 2.8b, where parallel light impinging on the lens to the left is concentrated down to a small focal point by this effect, before once again diverging. The distance from the lens to the point where the light rays are brought together is called the focal length, f, of the lens.
Introduction to Optoelectronic Materials
Published in Sam-Shajing Sun, Larry R. Dalton, Introduction to Organic Electronic and Optoelectronic Materials and Devices, 2016
Nasser Peyghambarian, M. Fallahi
Optical waveguides are the most basic and essential elements in integrated optics and have been studied in depth [11,12]. The fundamental requirement in guided waves is the process of total internal reflection (TIR). Total internal reflection is a phenomenon through which a ray of light is totally reflected at the interface between two materials with different refractive indices. An incident ray traveling from a medium of index n2 to a medium of index n1 satisfies Snell’s law described by () n1sinθ1=n2sinθ2
Domain decomposition of finite element models utilizing eight meta-heuristic algorithms: A comparative study
Published in Mechanics Based Design of Structures and Machines, 2020
In 2012, Kaveh and Khayatazad (2012) developed the Ray Optimization (RO) algorithm as a new population-based metaheuristic conceptualized based on Snell’s light refraction law when light travels from a lighter medium to a darker medium. RO applied successfully to some of the structural optimization problems. Based on Snell’s light refraction law, when light travels from a medium to another, it refracts. The refraction depends on (1) the angle between the incident ray and the normal vector of the interface surface of two mediums and (2) the refraction index ratio of two mediums. Its direction changes in a way that gets closer to the normal vector when it passes from a lighter medium to a darker one. In fact, RO aims to improve the quality of the solutions by refracting the rays toward the promising points obtained based on the best-known solution by each agent and all of them.