Related Experiment Video
Updated: Jun 17, 2026

Evanescent Field Based Photoacoustics: Optical Property Evaluation at Surfaces
Published on: July 26, 2016
Optical refractive index of air: dependence on pressure, temperature and composition
1Institute for Telecommunication Sciencesand Aeronomy, Environmental Science Services Administration,Boulder, Colorado 80302, USA.
Abstract:
The theoretical background and present status of formulas for the refractive index of air are reviewed. In supplement to Edlén's recently revised formula for relative refractivity, the density dependence of refractive index is reanalyzed. New formulas are presented for both phase and group refractive index which are more useful over a wide range of pressure, temperature, and composition than any presently available. The application of the new formulas to optical distance measuring is briefly discussed.
Related Concept Videos
Variation of Atmospheric Pressure
Assuming the air temperature is constant at a given altitude and that the ideal gas law of thermodynamics describes the atmosphere to a good approximation, one can find the variation of atmospheric pressure with height.
Let p(y) be the atmospheric pressure at...
Deviation from Ideal Behaviour
Definition and Measurement of Pressure: Atmospheric Pressure, Barometer, and Manometer
Propagation of Waves
Consider a scenario where a wave propagates from a string of low linear mass density to a string of high linear mass density. In such a case, the reflected wave is out of phase with respect to the incident wave, however the...
Poiseuille's Law and Reynolds Number
Real Gases: Effects of Intermolecular Forces and Molecular Volume Deriving Van der Waals Equation

