I do not understand why refractive index of air,when nearly equal to 1,is proportional to the pressure of the air. If anybody can provide an answer with proper resource from which I can study on the matter,do help me.
Asked
Active
Viewed 31 times
0
-
1It is $n - 1$ that is proportional to pressure, where $n$ is the refractive index. – Puk Feb 24 '24 at 06:24
-
That much I know,but what is the underlying law that says such relation between pressure & refraction – Sumit Roy Feb 24 '24 at 09:45
1 Answers
0
The outer electron orbitals in a gas are susceptible to alteration in an applied field, sometimes called Stark effect. Those molecules can be polarized, in proportion to the number of outer electrons. By the usual (dilute gas) law, PV = nRT, we see that high pressure means increase in 'n/V', the molar concentration. Thus, the deviation from no response (index of refraction of vacuum :== 1.0) is proportional to pressure, because the population density of gas molecules is proportional to pressure, and the polarization response of molecules gives rise to larger response when there are more molecules.
Whit3rd
- 9,756