# List of refractive indices

Many materials have a well-characterized refractive index, but these indices depend strongly upon the frequency of light. Standard refractive index measurements are taken at yellow doublet sodium D line, with a wavelength of 589 nanometres.

There are also weaker dependencies on temperature, pressure/stress, et cetera, as well on precise material compositions (presence of dopants et cetera); for many materials and typical conditions, however, these variations are at the percent level or less. Thus, it is especially important to cite the source for an index measurement if precision is required.

In general, an index of refraction is a complex number with both a real and imaginary part, where the latter indicates the strength of absorption loss at a particular wavelength—thus, the imaginary part is sometimes called the extinction coefficient $k$. Such losses become particularly significant, for example, in metals at short (e.g. visible) wavelengths, and must be included in any description of the refractive index.

Refraction, critical angle and total internal reflection of light at the interface between two media.

## List

Some representative refractive indices
Materialλ (nm)nRef.
Vacuum1 (per definition)
Air at STP1.000277
Gases at 0 °C and 1 atm
Air589.291.000293[1]
Carbon dioxide589.291.00045[2]
Helium589.291.000036[1]
Hydrogen589.291.000132[1]
Liquids at 20 °C
Arsenic trisulfide and sulfur in methylene iodide1.9[5]
Benzene589.291.501[1]
Carbon disulfide589.291.628[1]
Carbon tetrachloride589.291.461[1]
Ethyl alcohol (ethanol)589.291.361[1]
Silicone oil1.52045[6]
Water589.291.3330[1]
Solids at room temperature
Titanium dioxide (also called Titania or Rutile )589.292.496[7]
Diamond589.292.419[1]
Strontium titanate589.292.41
Amber589.291.55[1]
Fused silica (also called Fused Quartz)589.291.458[1]
Sodium chloride589.291.544[8]
Other materials
Liquid helium1.025
Water ice1.31
Cornea (human)1.373/1.380/1.401[9]
Lens (human)1.386 - 1.406
Acetone1.36
Ethanol1.36
Glycerol1.4729
Bromine1.661
Teflon AF1.315[10]
Teflon1.35 - 1.38
Cytop1.34[11]
Sylgard 1841.43
Acrylic glass1.490 - 1.492
Polycarbonate1.584 - 1.586
PMMA1.4893 - 1.4899
PETg1.57
PET1.5750
Crown glass (pure)1.50 - 1.54
Flint glass (pure)1.60 - 1.62
Crown glass (impure)1.485 - 1.755
Flint glass (impure)1.523 - 1.925
Pyrex (a borosilicate glass)1.470[12]
Cryolite1.338
Rock salt1.516
Sapphire1.762–1.778
Sugar Solution, 25%1.3723[13]
Sugar Solution, 50%1.4200[13]
Sugar Solution, 75%1.4774[13]
Cubic zirconia2.15 - 2.18
Potassium Niobate (KNbO3)2.28
Moissanite2.65 - 2.69
Cinnabar (Mercury sulfide)3.02
Gallium(III) phosphide3.5
Gallium(III) arsenide3.927
Zinc Oxide3902.4
Germanium4.01
Silicon5903.96[14]

## References

1. Optics, Fourth Edition. Pearson Higher Education. 18 March 2003. ISBN 978-0-321-18878-6.
2. ^ Introduction to Geometrical and Physical Optics. McGraw-Hill Book Company, INC.. 1953.
3. ^ Handbook of Chemistry and Physics. Chemical Rubber Publishing Co.. 1957.
4. ^ Introduction to Optics, Third Edition. Pearson Prentice Hall. 2007. p. 221. ISBN 0-13-149933-5.
5. ^ Meyrowitz, R, A compilation and classification of immersion media of high index of refraction, American Mineralogist 40: 398 (1955)
6. ^ Silicon and Oil Refractive Index Standards
7. ^ RefractiveIndex.INFO - Refractive index and related constants
8. ^ College Physics, 6th Edition. Brooks/Cole. 2003. p. 692. ISBN 978-0-03-035114-3.
9. ^ "Refractive index of the human corneal epithelium and stroma". J Refract Surg. 11 (2): 100–105. 1995 Mar-Apr. PMID 7634138.
10. ^
11. ^ "Cytop". Retrieved 2010-10-14.
12. ^
13. ^ a b c
14. ^ "Optical Properties of Silicon". Retrieved 2009-05-31.