Patent ID: 7477827

Claim:
A variable optical attenuator comprising: an input port for receiving an input optical beam; a filter, comprising a transparent substrate with a plurality of alternating blocking stripes and linear apertures distributed between a first end and a second end of the transparent substrate, the filter disposed within the input optical beam such that at least one blocking stripe blocks a portion of the input optical beam and at least one linear aperture transmits an attenuated optical beam having an attenuation value; and an output port for outputting the attenuated optical beam; wherein the blocking stripes are laid out in a zigzag pattern with serrations on a leading and trailing edge, each blocking stripe having a stripe width and separated from a neighboring blocking stripe by an aperture width; wherein the filter has a travel direction directed from the first end to the second end; and wherein a ratio of the stripe width to the aperture width progressively increases with a distance from the first end along the travel direction.