Abstract: A variable optical attenuator is disclosed, which attenuates a beam of light while preserving its polarization substantially independent of wavelength. The beam of light is attenuated by a filter patterned with a grating of blocking stripes with serrated edges, which partially block and partially transmit the beam of light, respectively. The serrated edges provide for low polarization dependent loss. Along a length of the filter, a mark to space ratio of blocking stripe and aperture widths increases. By a linear translation of the filter along its length attenuation can be varied to a desired value. A stepper motor with lead screw can provide a suitable linear translation to give the filter a latching property.

Abstract: A variable optical attenuator is disclosed, which attenuates a beam of light while preserving its polarization substantially independent of wavelength. The beam of light is attenuated by a filter patterned with a grating of blocking stripes with serrated edges, which partially block and partially transmit the beam of light, respectively. The serrated edges provide for low polarization dependent loss. Along a length of the filter, a mark to space ratio of blocking stripe and aperture widths increases. By a linear translation of the filter along its length attenuation can be varied to a desired value. A stepper motor with lead screw can provide a suitable linear translation to give the filter a latching property.