Refractive index: Difference between revisions

Revision as of 20:00, 25 April 2025

Revision as of 20:13, 25 April 2025

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==Applications==

{{unreferenced section|date=September 2014}}

The refractive index is an important property of the components of any [[optical instrument]]. It determines the focusing power of lenses, the dispersive power of prisms, the reflectivity of [[anti-reflective coating|lens coatings]]<ref>{{Cite book |last=Willey |first=Ronald R. |url=https://www.spiedigitallibrary.org/ebooks/FG/Field-Guide-to-Optical-Thin-Films/eISBN-9780819478221/10.1117/3.668269 |title=Field Guide to Optical Thin Films |date=2006-01-27 |publisher=SPIE |isbn=978-0-8194-7822-1 |doi=10.1117/3.668269}}</ref>, and the light-guiding nature of [[optical fiber]]<ref>{{Cite journal |last=Takeo |first=Takashi |last2=Hattori |first2=Hajime |date=1982-10-01 |title=Optical Fiber Sensor for Measuring Refractive Index |url=https://iopscience.iop.org/article/10.1143/JJAP.21.1509 |journal=Japanese Journal of Applied Physics |volume=21 |issue=10R |pages=1509 |doi=10.1143/JJAP.21.1509 |issn=0021-4922}}</ref>. Since the refractive index is a fundamental physical property of a substance, it is often used to identify a particular substance, confirm its purity, or measure its concentration. The refractive index is used to measure solids, liquids, and gases. Most commonly it is used to measure the concentration of a solute in an [[aqueous solution]]<ref>{{Cite journal |last=Warren |first=John R. |last2=Gordon |first2=Julius A. |date=January 1966-01 |title=On the Refractive Indices of Aqueous Solutions of Urea |url=https://pubs.acs.org/doi/abs/10.1021/j100873a507 |journal=The Journal of Physical Chemistry |language=en |volume=70 |issue=1 |pages=297–300 |doi=10.1021/j100873a507 |issn=0022-3654}}</ref>. It can also be used as a useful tool to differentiate between different types of gemstone, due to the unique [[Chatoyancy|chatoyance]] each individual stone displays. A [[refractometer]] is the instrument used to measure the refractive index. For a solution of sugar, the refractive index can be used to determine the sugar content (see [[Brix]]).

==See also==