In: Physics
Unpolarized light with an intensity of 26.4 passes through a polarizer whose transmission axis is vertically oriented. What is the direction of polarized beam and intensity of the transmitted light? If the polarizer’s transmission axis is at an angle of 69.0° with the vertical, what is the intensity of the transmitted light and its?
Let be the intensity of
the unpolarized light incident on the polarizing sheet. Let
be the angle
between the polarizing direction of the sheet and the direction of
vibration of the electric vector of the incident light. By Malus'
law, the intensity of the plane-polarized light transmitted by the
sheet is given by,
As the incident light is unpolarized, the electric vector in it
vibrates randomly in all possible directions in a plane
perpendicular to the direction of propagation. Hence we shall put
average value of in the
above equation. Thus,
This is independent of the transmission axix orientation with
the vertical direction. Thus in both the cases the intensity of the
transmitted light will be,