Refractive indexProperty in opticsA ray of light being refracted through a glass slabRefraction of a light rayIn optics, the refractive index (also called refraction index or index of refraction), often denoted n, is the ratio of the speed of light in vacuum (c) to the speed of light in a given optical medium (v), n=c/v. The refractive index determines how much the path of light is bent, or refracted, when entering a material, as described by Snell's law of refraction, n1 sin θ1 = n2 sin θ2, where θ1 and θ2 are the angle of incidence and angle of refraction, respectively, of a ray crossing the interface between two media with refractive indices n1 and n2.
Optical pathOptical path (OP) is the trajectory that a light ray follows as it propagates through an optical medium. The geometrical optical-path length or simply geometrical path length (GPD) is the length of a segment in a given OP, i.e., the Euclidean distance integrated along a ray between any two points. The mechanical length of an optical device can be reduced to less than the GPD by using folded optics.
Ray tracing (physics)In physics, ray tracing is a method for calculating the path of waves or particles through a system with regions of varying propagation velocity, absorption characteristics, and reflecting surfaces. Under these circumstances, wavefronts may bend, change direction, or reflect off surfaces, complicating analysis. Historically, ray tracing involved analytic solutions to the ray's trajectories.
Arc lengthArc length is the length of a curve from beginning to end. Conceptually, if we imagined the curve as a string, the arc length is how long the string would be if we straightened it out. It can be formalized mathematically for smooth curves using vector calculus and differential geometry, or for curves that might not necessarily be smooth as a least upper bound of lengths of polygonal chains.Optical mediumIn optics, an optical medium is material through which light and other electromagnetic waves propagate. It is a form of transmission medium. The permittivity and permeability of the medium define how electromagnetic waves propagate in it.
LightLight, visible light, or visible radiation is electromagnetic radiation that can be perceived by the human eye. Visible light spans the visible spectrum and is usually defined as having wavelengths in the range of 400–700 nanometers (nm), corresponding to frequencies of 750–420 terahertz.
DiffractionDiffraction is the deviation of waves from straight-line propagation due to an obstacle or through an aperture, without any change in their energy. Diffraction is the same physical effect as interference, but interference is typically used for the superposition of a few waves, while the term diffraction is used when many waves are superposed.
OpticsBranch of physics that studies lightOptics is the branch of physics that studies the behaviour, manipulation, and detection of electromagnetic radiation, including its interactions with matter and instruments that use or detect it. Optics usually describes the behaviour of visible, ultraviolet, and infrared light. The study of optics extends to other forms of electromagnetic radiation, including radio waves, microwaves, and X-rays.
Line integralDefinite integral of a scalar or vector field along a path Part of a series of articles aboutCalculus ∫ a b f ′ ( t ) d t = f ( b ) − f ( a ) {\displaystyle \int _{a}^{b}f'(t)\,dt=f(b)-f(a)} Fundamental theorem Limits Continuity Rolle's theorem Mean value theorem Inverse function theorem Differential Definitions Derivative (generalizations) Differential infinitesimal of a function total Concepts Differentiation notation Second derivative Implicit differentiation Logarithmic differentiation Related rates Taylor's theorem Rules and identities Sum Product Chain Power Quotient L'Hôpital's rule Inverse General Leibniz Faà di Bruno's formula Reynolds Integral Lists of integrals Integral transform Leibniz integral rule Definitions Antiderivative Integral (improper) Riemann integral Lebesgue integration Contour integration Integral of inverse functions Nonelementary integral Integration by Parts Discs Cylindrical shells Substitution (trigonometric, tangent half-angle, Euler) Euler's formula Partial fractions (Heaviside's method) Changing order Reduction formulae Differentiating under the integral sign Risch algorithm Series Geometric (arithmetico-geometric) Harmonic Alternating Power Binomial Taylor Convergence tests Summand limit (term test) Ratio Root Integral Direct comparison Limit comparison Alternating series Cauchy condensation Dirichlet Abel Vector Gradient Divergence Curl Laplacian Directional derivative Identities Theorems Gradient Green's Stokes' Divergence Generalized Stokes Helmholtz decomposition Multivariable Formalisms Matrix Tensor Exterior Geometric Definitions Partial derivative Multiple integral Line integral Surface integral Volume integral Jacobian Hessian Theorems Clairaut's Fubini's Advanced Calculus on Euclidean space Generalized functions Limit of distributions Specialized Fractional Malliavin Stochastic Variations Miscellanea Precalculus History Glossary List of topics Integration Bee Mathematical analysis Nonstandard analysis vte In mathematics, a line integral is an integral where the function to be integrated is evaluated along a curve.
Phase (waves)In physics and mathematics, the phase (symbol φ or ϕ) of a wave or other periodic functionF{\displaystyle F} of some real variable t{\displaystyle t} (such as time) is an angle-like quantity representing the fraction of the cycle covered up to t{\displaystyle t}. It is expressed in such a scale that it varies by one full turn as the variable t{\displaystyle t} goes through each period (and F(t){\displaystyle F(t)} goes through each complete cycle).
Wave interferenceIn physics, interference is a phenomenon in which two coherent waves are combined by adding their intensities or displacements with due consideration for their phase difference. The resultant wave may have greater amplitude (constructive interference) or lower amplitude (destructive interference) if the two waves are in phase or out of phase, respectively.
Ray (optics)In optics, a ray is an idealized geometrical model of light or other electromagnetic radiation, obtained by choosing a curve that is perpendicular to the wavefronts of the actual light, and that points in the direction of energy flow. Rays are used to model the propagation of light through an optical system, by dividing the real light field up into discrete rays that can be computationally propagated through the system by the techniques of ray tracing.*As an Amazon Associate I earn from qualifying purchases.