Refractometry:
Reporting Results
The standard format for reporting the index of refraction is shown below:
The italicized n denotes refractive index, the superscript indicates the temperature in degrees Celsius (most values are determined at 20 °C), and the subscript denotes the wavelength of light (in this case the D indicates the sodium D line at 589.3 nm). Routine refractive indexes are nearly always measured using the sodium D line, but if a different wavelength of light is used the wavelength (in nm) is inserted in place of the subscript D.
