List of refractive indices

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Some representative refractive indices
Material λ (nm) n Ref.
Vacuum 1 (exactly)
Air @ STP 1.0002926
Gases @ 0 °C and 1 atm
Air 589.29 1.000293 [1]
Helium 589.29 1.000036 [1]
Hydrogen 589.29 1.000132 [1]
Carbon dioxide 589.29 1.00045 [2]

[3] [4]
Liquids @ 20 °C
Benzene 589.29 1.501 [1]
Water 589.29 1.333 [1]
Ethyl alcohol (ethanol) 589.29 1.361 [1]
Carbon tetrachloride 589.29 1.461 [1]
Carbon disulfide 589.29 1.628 [1]
Solids at room temperature
Diamond 589.29 2.419 [1]
Strontium titanate 589.29 2.41
Amber 589.29 1.55 [1]
Fused silica 589.29 1.458 [1]
Sodium chloride 589.29 1.50 [1]
Other materials
Pyrex (a borosilicate glass) 1.470 [5]
Ruby 1.760 [5]
Water ice 1.31
Cryolite 1.338
Acetone 1.36
Ethanol 1.36
Teflon 1.35 - 1.38
Glycerol 1.4729
Acrylic glass 1.490 - 1.492
Rock salt 1.516
Crown glass (pure) 1.50 - 1.54
Salt (NaCl) 1.544
Polycarbonate 1.584 - 1.586
PMMA 1.4893 - 1.4899
PETg 1.57
PET 1.5750
Flint glass (pure) 1.60 - 1.62
Crown glass (impure) 1.485 - 1.755
Fused Quartz 1.46
Bromine 1.661
Flint glass (impure) 1.523 - 1.925
Cubic zirconia 2.15 - 2.18
Diamond 2.419
Moissanite 2.65 - 2.69
Cinnabar (Mercury sulfide) 3.02
Gallium(III) phosphide 3.5
Gallium(III) arsenide 3.927
Silicon 4.01 [6]

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 sodium D line, 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.

[edit] References

  1. ^ a b c d e f g h i j k l (18 March 2003) Optics, Fourth Edition. Pearson Higher Education. ISBN 9780321188786. 
  2. ^ (1953) Introduction to Geometrical and Physical Optics. McGraw-Hill Book Company, INC.. 
  3. ^ (1957) Handbook of Chemistry and Physics. Chemical Rubber Publishing Co.. 
  4. ^ (2007) Introduction to Optics, Third Edition. Pearson Prentice Hall, 221. ISBN 0-13-149933-5. 
  5. ^ a b University of Liverpool. Absolute Refractive Index. Retrieved on 2007-10-18.
  6. ^ Optical Properties of Silicon. Retrieved on 2008-04-03.

[edit] See also

[edit] External links