Question

An elliptically polarised wave is incident on a linear polariser. The intensity after the polariser is measured using a photodiode. Briefly explain how you expect the measured intensity to vary as you rotate the polariser over 360 degrees.

Answer 1

In case of elliptically polarised light falling on linear polarizer , the intensity of light transmitted through the polarizer varies with the rotation of of polarizer from I_{​​​max ​​ ^to} I_{​​​​​​min.} I_{​​​​​​Max} is found when the polarizer pass axis coincides with the semi-major axis of the ellipse and I_{​​​​​​min} occurs when the polarizer pass axis coincides with the semi-minor axis of the ellipse. Hence on rotation of polarizer through 360^° , we can observe two I_{​​​​​​max} and two I_{​​​​​​min} on a detector plane. Hence variations also seems to be like an ellipse.