Tag: Optics
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Astigmatism
Introduction Astigmatism is a common vision condition that causes blurred or distorted vision as a result of an irregular curvature of the cornea or the lens of the eye. In an astigmatic eye, the light rays are not converged to a single focus point to provide clear vision. Instead, they are focused on multiple points,…
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Chapter 2: Magnification
2.1 Introduction to Magnification In optics, magnification is the factor by which an object’s size appears larger or smaller than its actual size when viewed through an optical instrument, such as a lens or mirror. Magnification can be expressed as a dimensionless value or as a ratio of the size of the image to the…
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Kramers-Kronig Relations
Introduction The Kramers-Kronig relations are fundamental theorems in the fields of physics and engineering, specifically in optics and electrical engineering. These relations connect the real and imaginary parts of any complex function that obeys certain causality conditions. They are primarily used in the analysis of linear, passive systems. Mathematical Formulation of the Kramers-Kronig Relations Let…
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Gouy Phase
Introduction The Gouy phase is a phase shift that occurs for a beam of light when it propagates through a focusing or defocusing element, like a lens. This phase shift, named after the French scientist Léon Gouy, is an essential aspect of Gaussian beams and wave optics. Gaussian Beams A Gaussian beam is a beam…
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Babinet’s Principle
Introduction Babinet’s Principle, named after French physicist Jacques Babinet, is a theorem concerning diffraction in the field of optics. The principle states that the diffraction pattern from an opaque body is identical to the pattern from a hole of the same size and shape except for the overall forward beam intensity. Statement of Babinet’s Principle…
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Airy Disk
Introduction The Airy disk is the bright spot at the center of a pattern that is produced when a plane wave of light is diffracted by a circular aperture. It is named after the British astronomer Sir George Biddell Airy. The pattern consists of a bright central region, or disk, surrounded by a series of…
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Optics
Introduction Optics is a branch of physics that studies the behavior and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behavior of visible, ultraviolet, and infrared light. Nature of Light Light is an electromagnetic wave, and its speed in a vacuum…
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Refraction
Introduction Refraction is the change in direction of a wave passing from one medium to another caused by its change in speed. This fundamental concept in physics is most commonly observed when a wave, such as light or sound, passes from air into water or from air into glass. The Principle of Refraction When light…