How do you calculate the absolute index of refraction?

1 Answer
May 3, 2015

Absolute refractive index is the refractive index when a light ray passes from air to the given medium or from a medium to air.

We thus apply Snell's law as follows(for a ray going from air to a medium),

#n_asini=n_msinr#

where #n_m# is the refractive index of the medium
#n_a# is the refractive index of air
#i# is the angle of incidence
#r# is the angle of refraction

Make #n_m# the subject in the above equation

#=>n_m= (n_asini)/(sinr)#
#n_a=1#

#=> n_m= (sini)/(sinr)#

Also, another definition says that #n_m= c/c_m= "speed of light in vacuum"/"speed of light in the medium"#