Geometrical Optics

Consider a configuration of n identical units, each consisting of three layers. The first layer is a column of air of height h=‌

1

3

‌cm, and the second and third layers are of equal thickness d= ‌

√3−1

2

‌cm, and refractive indices µ1=√‌

3

2

and µ2=√3, respectively. A light source 0 is placed on the top of the first unit, as shown in the figure. A ray of light from 0 is incident on the second layer of the first unit at an angle of θ=60∘ to the normal. For a specific value of n, the ray of light emerges from the bottom of the configuration at a distance l=‌

8

√3

‌cm, as shown in the figure. The value of n is