(b) Figure 1 shows an incident light beam passing through multiple
translucent slabs with increasing indices of refraction, i.e n, 2n, 3?, ..., kn.
Here, n is the index of refraction of the first slab. The incident light at an
angle $\theta_1$ will get refracted multiple times until the beam appears horizontal
inside these slabs.
SULIT
(i) Derive an inequality expression that predicts the number of slabs,
k, needed so that the light beam is almost horizontal inside the
slabs, i.e., the angle between the outgoing beam and the x-axis,
$\theta_o$, is less than $10^{-6}$? Assume that the region outside the mutiple
slabs has the index of refraction, $n = 1$.
(5/100)
(ii) What is the angle between the x-axis and the light beam that exits
the final slab, if the incident angle is $\theta_i = 0.25\pi$ rad?
(6/100)
