•
•Equation for Refraction (Snell)
•
• sin Ф1
n1
η2 if medium 1
•---------- =
----- = ------
= η2
• sin Ф2 n2 η1
is air η1 =
1.0
•
•Magnitude
of the direction change (i.e., size of the angle depends on wavelength (shown in equation as n) this is how a prism works
•Direction
of bending depends on relative values of η for each
medium. Going from low η to higher, the ray bends toward the normal.
Going from higher η to lower the ray bends away from the normal.