Since a sheet of Polaroid is not an ideal polarizer not all the energy of the E-vibrations parallel tome TA are transmitted, nor are all E-vibrations perpendicular to the TA absorbed. Suppose an energy fraction a is transmitted in the first case and a fraction b is transmitted in the second.

a. Extend Malus' law by calculating the irradiance transmitted by a pair of such polarizes with angle 0 between their TAs. Assume initially unpolarized light of irradiance 10. Show that Malus' law follows in the ideal case.

b. Let a = 0.95 and = 0.05 for a given sheet of Polaroid. Compare the irradiance with that of an ideal polarizer when unpolarized light is passed through two such sheets having a relative angle between TAs of 0e, 30`. 45. and 90`.

Figure 1.

TA Polarizer 2 TA Polarizer 1 Unpolarized light