Abstract: An optical processing device for light radiation provides non-linear transfer functions in an optical guide. A coupled quantum well modulator is reverse biased by an adjustable dc voltage source through an impedance and light radiation to be processed is sent in parallel with the layers composing the modulator guiding zone. The coupled quantum well modulator has a multiplicity of layers including some which form a guide zone comprised of a sequence of alternating quantum wells and barrier layers. The light radiation to be processed passes parallel to the layers through this guiding zone.