Light is entering a polarizer or set of polarizers from the

Light is entering a polarizer or set of polarizers from the left. Determine the relative intensity of the light exiting on the right after passing through all of the polarizers. The dashed vertical lines represent the vertical reference. The solid lines represent either the polarization angle of the light or the transmission angle of the polarizer. CW represents clockwise and CCW represents counterclockwise as viewed from the right looking back to the left along the path of the light. Horizontally polarized light passes through a polarizer with the transmission axis oriented 90degree relative to the vertical and then through a second polarizer oriented 90degree relative to the vertical. Unpolarized light enters from the left and passes first through a polarizer oriented 45degreeCCW from the vertical and the through a polarizer oriented 45degree CW.

Solution

(a). full intensity.

Let the intensity of the horizontally polarized light be I.

Intensity of the horizontallypolarized light after passing through polarizer with transmission axis oriented 90 ^o relative to the vertical is

   I \' = I cos ² (90-90) = I cos ² 0 = I             Since cos 0 = 1

Intensity after passing through second polarizer I \" = I \' cos ² 0

                                                                         = I (1) = I

(b). zero intensity

Let the intensity of the unpolarized light be Io.

Intensity of the light after passing through first polarizer is I = Io/2

Intensity of the light after passing through second polarizer is I \' = I cos ² (45+45)

                                                                                            =(Io/2) cos ² 90

                                                                                            = 0         Since cos90 =0