Question

A half-wave plate is placed in between a polarizer and a photo-director. When the optic axis of the quarter-wave plate is kept initially parallel to the pass axis of the polarizer and perpendicular to the direction of light propagation. The intensity of light passing through the quarter-wave plate is measured to be I₀ (see figure). If the quarter wave plate is now rotated by 45° about an axis parallel to the light propagation, what would be the intensity of the emergent light measured by the photo-director?

(1)   I₀/√2

(b)  I₀/2

(c)   I₀/2√2

(d)  I₀

Answer 1

Correct option (b)  I₀/2

Explanation:

After passing through half wave plate the plane polarized light of intensity I₀  will remain in early polarized rotated at 45° but the intensity is driven by Malu’s law