Patent ID: 6404970
Filing Date: 2002-06-11
Classification: G02B

Abstract:
A variable optical attenuator for attenuating a beam of light comprising an optical signal having a diameter less than about 1 mm, comprising:a filter comprising a sheet having a plurality of apertures discretely arranged for providing a transmission gradient along a path defining a gradient axis of the sheet, the plurality of apertures having a predetermined shape, size and distribution, and having a length and a distance therebetween that is substantially smaller than the diameter of the beam of light; an input port for launching the beam of light towards the filter at a predetermined angle; an output port for receiving substantially focussed light from the filter; and, means for providing relative movement between the beam of light and the filter for effecting variable attenuation of the beam of light in dependence upon a position of said filter relative to said beam of light.