# Physical optics

Physical optics

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. This usage tends not to include effects such as quantum noise in optical communication, which is studied in the sub-branch of coherence theory.

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. In this context, it is an intermediate method between geometric optics, which ignores wave effects, and full wave electromagnetism, which is a precise theory. The word "physical" means that it is more physical than geometric or ray optics and not that it is an exact physical theory.

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. This resembles the Born approximation, in that the details of the problem are treated as a perturbation.

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. 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. 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 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.

ee also

*Diffraction
*Electromagnetic modeling
*History of optics
*Interference
*Polarization

References

*cite book |author=Serway, Raymond A.; Jewett, John W. | title=Physics for Scientists and Engineers (6th ed.) | publisher=Brooks/Cole | year=2004 | id=ISBN 0-534-40842-7
*cite book | author=Akhmanov, A ; Nikitin, S. Yu | title=Physical Optics |publisher= Oxford University Press |year=1997| id=ISBN 0-19-851795-5
*"A Double-Edge-Diffraction Gaussian-Series Method for Efficient Physical Optics Analysis of Dual-Shaped-Reflector Antennas", "Antennas and Propagation", August 2005, p. 2597
*"The physical optics method in electromagnetic scattering" J. S. Asvestas, Journal of Mathematical Physics, February 1980, Volume 21, Issue 2, pp. 290-299

Wikimedia Foundation. 2010.

### Look at other dictionaries:

• physical optics — fizikinė optika statusas T sritis fizika atitikmenys: angl. physical optics vok. physikalische Optik, f rus. физическая оптика, f pranc. optique physique, f …   Fizikos terminų žodynas

• physical optics — noun plural but usually singular in construction : a branch of optics that deals with the description and explanation of all optical phenomena in terms of physical theories (as undulatory theory, electromagnetic phenomena, or quantum mechanics) * …   Useful english dictionary

• physical optics — the branch of optics concerned with the wave properties of light, the superposition of waves, the deviation of light from its rectilinear propagation in a manner other than that considered by geometrical optics, the interaction of light with… …   Universalium

• Optics Communications —   Abbreviated title (ISO) …   Wikipedia

• Optics Software for Layout and Optimization — (OSLO) is an optical design program originally developed at the University of Rochester in the 1970s. The first commercial version was produced in 1976 by Sinclair Optics. Since then, OSLO has been rewritten several times as computer technology… …   Wikipedia

• Optics — For the book by Sir Isaac Newton, see Opticks. Optical redirects here. For the musical artist, see Optical (artist). Optics includes study of dispersion of light. Optics is the branch of …   Wikipedia

• optics — /op tiks/, n. (used with a sing. v.) the branch of physical science that deals with the properties and phenomena of both visible and invisible light and with vision. [1605 15; < ML optica < Gk optiká, n. use of neut. pl. of OPTIKÓS; see OPTIC,… …   Universalium

• optics — Synonyms and related words: Newtonian physics, acoustics, actinology, actinometry, aerophysics, applied physics, astrophysics, basic conductor physics, biophysics, catoptrics, chemical physics, cryogenics, crystallography, cytophysics, dioptrics …   Moby Thesaurus

• physical science — physical scientist. 1. any of the natural sciences dealing with inanimate matter or with energy, as physics, chemistry, and astronomy. 2. these sciences collectively. [1835 45] * * * Introduction       the systematic study of the inorganic world …   Universalium

• Optics and Spectroscopy — is scientific journal, English version of the Russian journal Оптика и спектроскопия (optika i spektroskopiya), founded in 1956. It publishes research and review papers on a monthly basis. Covers various topics of spectroscopy of electromagnetic… …   Wikipedia