What happens if I have a rotating half-wave plate?

[Corwin_S]

Hey there,

What would happen if I had a half-wave plate, and I rotated it at like 1 Hz? If I stick a linear polarizer on the other end, what would my outcoming beam look like if the incoming one was natural light?

 

[blue_leaf77]

What do you mean by natural light?

 

[Corwin_S]

Sorry. Unpolarized light from a laser.

 

[blue_leaf77]

Unpolarized light can be modeled as a randomly varying linearly polarized light, i,e, take a snapshot of the wavefront you will see it is polarized in one direction, take another snapshot at different time you will see it's polarized in another direction, it's just that there is no fixed relationship connecting the polarization states at different times. Now a half-wave plate is pure rotator, it only rotates the polarization direction of a linearly polarized light but keeps the intensity constant. If you let your unpolarized light pass through a half-wave plate, obviously the outgoing light will also be unpolarized without change in intensity because at every instant of time the polarization of an incident wavefront is just rotated. If you rotate the half-wave plate with a certain rate, do you think the polarization state as well as the intensity of an incoming unpolarized light will change given the random nature of the polarization state?