Transparency and translucency: Difference between revisions

Revision as of 17:36, 9 May 2024

Revision as of 13:07, 10 May 2024

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{{See also|Light scattering}}

[[File:Silica core fiber minimum attenuation.jpg|thumb|Experimentally measured record low attenuation of silica core optical fiber. At 1550 nm wavelength attenuation components are determined as follows: Rayleigh scattering loss ~ 0.1200 dB/km, infrared absorption loss ~ 0.0150 dB/km, impurity absorption loss ~ 0.0047 dB/km, waveguide imperfection loss ~ 0.0010 dB/km.<ref>{{Cite journal |last=Khrapko |first=R. |last2=Logunov |first2=S. L. |last3=Li |first3=M. |last4=Matthews |first4=H. B. |last5=Tandon |first5=P. |last6=Zhou |first6=C. |date=2024-04-15 |title=Quasi Single-Mode Fiber With Record-Low Attenuation of 0.1400 dB/km |url=https://ieeexplore.ieee.org/document/10458691/ |journal=IEEE Photonics Technology Letters |volume=36 |issue=8 |pages=539–542 |doi=10.1109/LPT.2024.3372786 |issn=1041-1135}}</ref>|260x260px]]

[[Attenuation]] in [[Optical fiber|fiber optics]], also known as transmission loss, is the reduction in intensity of the light beam (or signal) with respect to distance traveled through a transmission medium. Attenuation coefficients in fiber optics usually use units of dB/km through the medium due to the very high quality of transparency of modern optical transmission media. The medium is usually a fiber of silica glass that confines the incident light beam to the inside. Attenuation is an important factor limiting the transmission of a signal across large distances. In optical fibers the main attenuation source is scattering from molecular level irregularities ([[Rayleigh scattering]])<ref>I. P. Kaminow, T. Li (2002), Optical fiber telecommunications IV, [https://books.google.com/books?id=GlxnCiQlNwEC&pg=PA223 Vol. 1, p. 223] {{webarchive|url=https://web.archive.org/web/20130527231335/http://books.google.com/books?id=GlxnCiQlNwEC&q&f=false&pg=PA223 |date=2013-05-27 }}</ref> due to structural disorder and compositional fluctuations of the [[Amorphous solid|glass structure]]. This same phenomenon is seen as one of the limiting factors in the transparency of infrared missile domes.<ref>{{Citationcite neededjournal|dateauthor1=NovemberArchibald, P.S. |author2=Bennett, H.E. |editor-first1=Stephen A. |editor-first2=Geoffery |editor-last1=Benton |editor-last2=Knight |name-list-style=amp |title=Scattering from infrared missile domes|bibcode=1978SPIE..133...71A|journal=Opt. Eng.|series=Optics in Missile Engineering |volume=17|page=647|year=1978|doi=10.1117/12.956078|s2cid=173179565 2010}}.</ref> Further attenuation is caused by light absorbed by residual materials, such as metals or water ions, within the fiber core and inner cladding. Light leakage due to bending, splices, connectors, or other outside forces are other factors resulting in attenuation.<ref>{{cite journal|author=Smith, R.G.|title=Optical power handling capacity of low loss optical fibers as determined by stimulated Raman and Brillouin scattering|journal=Appl. Opt.|volume=11|issue=11|pages=2489–94|year=1972|doi=10.1364/AO.11.002489|pmid=20119362|bibcode=1972ApOpt..11.2489S}}</ref><ref>{{cite journal|author1=Archibald, P.S. |author2=Bennett, H.E. |editor-first1=Stephen A. |editor-first2=Geoffery |editor-last1=Benton |editor-last2=Knight |name-list-style=amp |title=Scattering from infrared missile domes|bibcode=1978SPIE..133...71A|journal=Opt. Eng.|series=Optics in Missile Engineering |volume=17|page=647|year=1978|doi=10.1117/12.956078|s2cid=173179565 }}</ref>

==As camouflage==