A variable optical attenuator of the multiple-aperture type is disclosed. The attenuator comprises a thin element having a plurality of apertures therein. The plurality of apertures is arranged such that the size of most of the apertures increases along a distance of the thin element. In particular,...http://www.google.fr/patents/US6404970?utm_source=gb-gplus-shareBrevet US6404970 - Variable optical attenuator
