Variable optical attenuator with polarization compensation

摘要

An optical attenuator for attenuating an incident optical beam comprises at least two attenuating devices, each having a polarization dependent attenuation characteristic with a preferred orientation. The attenuating devices are arranged in the optical beam in a way that the preferred orientations of the polarization dependent attenuation characteristics substantially compensate each other, at least partially in defined locations. At least one attenuating device provides an attenuation characteristic wherein the attenuation for the incoming light beam varies in a defined direction. The preferred orientation of the polarization dependent attenuation characteristic of the at least one attenuating device is substantially in the same direction as the varying attenuation characteristics or substantially perpendicular thereto.