the two polaroids in a given set up, are kept 'crossed' with respect to each other. A third polaroid now put in between these two polaroids, can be rotated. Find an expression for the dependence of the intensity of light I, transmitted by the system, on the angle between the pass axis of first and the third polaroid.
Answers
Dear friends
Malus law states that when a perfect polarizer is placed in polarised beam of light,the intensity I of the light that passes through is I=I0cos2θi
where I0 is the initial intensity of the light, θi is the angle between the lights initial polarisation and the axis of the polarizer.
Therefore intensity of the light coming out of the second polarizer is Iocos2θ where θ is angle between the transmission axis P1 and P3 and I0 intensity of the incident light from on the first Polaroid P1 .
Maximum intensity : When the Polaroid is rotated in the path of the plane polarised light its intensity will be maximum when the vibration of the plane polarised light are parallel to the axis of the Polaroid.
Minimum Intensity: When the direction of the vibration becomes perpendicular to the axis of the crystal.
Regards.