Editing Perfect mirror (section)

==General==
Domestic mirrors are not perfect mirrors as they [[absorption (optics)|absorb]] a significant portion of the [[light]] which falls on them.

[[Dielectric mirror]]s are [[glass]] or other substrates on which one or more layers of dielectric material are deposited, to form an [[optical coating]]. A very complex dielectric mirror can reflect up to 99.999% of the light incident upon it, for a narrow range of [[wavelength]]s and [[Angle|angles]]. A simpler mirror may reflect 99.9% of the light, but may cover a broader range of wavelengths.

Almost any dielectric material can act as a perfect mirror through [[total internal reflection]]. This effect only occurs at shallow angles, however, and only for light inside the material. The effect happens when light goes from a medium with a higher [[index of refraction]] to one with a lower value (like air).

A new type of dielectric "perfect mirror" was developed in 1998 by researchers at [[Massachusetts Institute of Technology|MIT]].<ref>{{cite web|title=MIT researchers create a 'perfect mirror' |url=http://web.mit.edu/newsoffice/1998/mirror.html |publisher=MIT |date=27 November 1998 |accessdate=2012-11-18 |url-status=dead |archiveurl=https://web.archive.org/web/20110514000016/http://web.mit.edu/newsoffice/1998/mirror.html |archivedate=May 14, 2011 }}</ref><ref>{{cite journal |title=A Dielectric Omnidirectional Reflector |url=https://www.science.org/doi/10.1126/science.282.5394.1679 |journal=Science |date=November 26, 1998 |doi=10.1126/science.282.5394.1679 |accessdate=2008-09-22|last1=Fink |first1=Yoel |last2=Winn |first2=Joshua N. |last3=Fan |first3=Shanhui |last4=Chen |first4=Chiping |last5=Michel |first5=Jurgen |last6=Joannopoulos |first6=John D. |last7=Thomas |first7=Edwin L. |volume=282 |issue=5394 |pages=1679–1682 |url-access=subscription }}</ref> These unusual mirrors are very efficient reflectors over a broad range of angles and wavelengths, and are insensitive to [[Polarization (waves)|polarization]]. A version of the perfect mirror that was developed at MIT for military use is used by [[OmniGuide]] in laser surgery.<ref>{{cite web |title= From military device to life-saving surgery tool |url=http://www.cnn.com/2008/HEALTH/12/19/laser.surgery/index.html |publisher=CNN |date=December 19, 2008 |accessdate=2008-12-19}}</ref>