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In physics, physical optics, or wave optics, is the branch of optics which studies interference, diffraction, polarization, and other phenomena for which the ray approximation of geometric optics is not valid. Physics (Greek Physis - φύσις in everyday terms is the Science of Matter and its motion. In physics interference is the addition ( superposition) of two or more Waves that result in a new wave pattern Diffraction is normally taken to refer to various phenomena which occur when a wave encounters an obstacle Polarization ( ''Brit'' polarisation) is a property of Waves that describes the orientation of their oscillations This usage tends not to include effects such as quantum noise in optical communication, which is studied in the sub-branch of coherence theory. Quantum noise is uncertainty of some physical quantity due to its quantum origin Optical communication is any form of Telecommunication that uses Light as the transmission medium In Physics, coherence theory is the study of optical effects arising from partially coherent light and radio sources

The physical optics approximation

Physical optics is also the name of a high frequency approximation (short-wavelength approximation) commonly used in optics, electrical engineering and applied physics. A high frequency approximation (or "high energy approximation" for Scattering or other Wave propagation problems in Physics or Engineering In Physics wavelength is the distance between repeating units of a propagating Wave of a given Frequency. An approximation (represented by the symbol ≈ is an inexact representation of something that is still close enough to be useful Electrical engineering, sometimes referred to as electrical and electronic engineering, is a field of Engineering that deals with the study and application of In this context, it is an intermediate method between geometric optics, which ignores wave effects, and full wave electromagnetism, which is a precise theory. A wave is a disturbance that propagates through Space and Time, usually with transference of Energy. Electromagnetism is the Physics of the Electromagnetic field: a field which exerts a Force on particles that possess the property of The word theory has many distinct meanings in different fields of Knowledge, depending on their methodologies and the context of discussion. The word "physical" means that it is more physical than geometric or ray optics and not that it is an exact physical theory. Geometry ( Greek γεωμετρία; geo = earth metria = measure is a part of Mathematics concerned with questions of size shape and relative position In Optics, a ray is an idealized narrow Beam of light. Rays are used to model the propagation of Light through an optical system by dividing the real light

This approximation consists of using ray optics to estimate the field on a surface and then integrating that field over the surface to calculate the transmitted or scattered field. The European Space Agency 's INTErnational Gamma-Ray Astrophysics Laboratory ( INTEGRAL) is detecting some of the most energetic radiation that comes from space This resembles the Born approximation, in that the details of the problem are treated as a perturbation. In Scattering theory and in particular in Quantum mechanics, the Born approximation consists of taking the incident field in place of the total field as the driving This article describes perturbation theory as a general mathematical method

In optics, it is a standard way of estimating diffraction effects. In radio, this approximation is used to estimate some effects that resemble optical effects. Radio is the transmission of signals by Modulation of electromagnetic waves with frequencies below those of visible Light. It models many interference, diffraction and polarization effects but not the dependence of diffraction on polarization. Since it is a high frequency approximation, it is often more accurate in optics than for radio.

In optics, it typically consists of integrating ray estimated field over a lens, mirror or aperture to calculate the transmitted or scattered field.

In radar scattering it usually means taking the current that would be found on a tangent plane of similar material as the current at each point on the front, i. Radar is a system that uses electromagnetic waves to identify the range altitude direction or speed of both moving and fixed objects such as Aircraft, ships Scattering is a general physical process whereby some forms of Radiation, such as Light, Sound or moving particles for example are forced to deviate from Electric current is the flow (movement of Electric charge. The SI unit of electric current is the Ampere. For the tangent function see Trigonometric functions. For other uses see Tangent (disambiguation. e. the geometrically illuminated part, of a scatterer. Current on the shadowed parts is taken as zero. The approximate scattered field is then obtained by an integral over these approximate currents. This is useful for bodies with large smooth convex shapes and for lossy (low reflection) surfaces.

The ray optics field or current is generally not accurate near edges or shadow boundaries, unless supplemented by diffraction and creeping wave calculations. According to the principle of Diffraction, when a wave front passes an obstruction it spreads out into the shadowed space

See also

References

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