- #1
IMESS
The combination of a half-wave plate followed by a polarizer is commonly used as a variable attenuator for polarized lasers. The idea is that the beam enters the half-wave plate, and you rotate the half-wave plate leading to a rotation of the polarization direction of the beam. As the beam is then rotated with respect to the direction of the polarizer plate, you get attenuation of the beam. However, as the beam is already polarized before it enters the 1/2 wave plate, wouldn't you be able to achieve the same thing by just leaving out the 1/2 wave plate, and rotating the polarizer?