In the figure below, a beam of unpolurized light with initial Intensity i_0 = 54
ID: 1521958 • Letter: I
Question
In the figure below, a beam of unpolurized light with initial Intensity i_0 = 540 W/m^2 is sent into a system of two polarizing sheets with polarizing directions at angles theta_1 40degree and theta_2 = 60degree with the direction of y axis (be careful with the angles), (a) What is the intensity of the light transmitted by the system of two polarizers? (b) What would be the intensity of the transmitted light, if the incoming beam of light was fully polarized with polarization parallel to the y axis? (c) What would be the intensity of the transmitted light, if a beam of unpolarized light was partially absorbed by the water filling the space between two polarizers distanced from each other by 0.5 m? (Assume the absorption coefficient of the water beta = 1.0 m^-1).Explanation / Answer
1.
a)
intensity of unpolarised light = Io = 540
intensity after passing the first polarizer = I1 = Io/2 = 540 /2 = 270
intensity after passing the first polarizer = I2 = I1 Cos2(60 - 40) = 270 Cos2(60 - 40) = 238.42
b)
intensity of polarised light = Io = 540
intensity after passing the first polarizer = I1 = Io Cos240 = 540 Cos240 = 316.88
intensity after passing the first polarizer = I2 = I1 Cos2(60 - 40) = 316.88 Cos2(60 - 40) = 279.81