A beam of unpolarized light of intensity I0 passes through a

A beam of unpolarized light of intensity I0 passes through a series of ideal polarizing filters with their polarizing directions turned to various angles as shown in (Figure 1)

Part A

What is the light intensity (in terms of I0) at point A?

Part B

What is the light intensity (in terms of I0) at point B?

Part C

What is the light intensity (in terms of I0) at point C?

Part D

If we remove the middle filter, what will be the light intensity at point C?

Solution

a) I_A= I₀ / 2

b) I_B = I₀ / 2 * cos 60 * cos 60

= 0.125 I₀

c) I_C = I₀ / 2 * cos 60 * cos 60 * cos (90 - 60)

= 0.0937 I₀

d) I_C = I₀ / cos² 90

= 0