Abstract: In an apparatus comprising an optical input device (220) controlled by a moving object and also comprising at least one further optical device (230,240) to be provided with electromagnetic radiation (225,226), wherein the input device comprises at least one diode laser (222) for supplying at least one measuring beam to a window (221) of the input device, the rear side of at least one of the ne diode lasers of the input device is optically coupled to at least one of the other optical devices so as to supply such a device with radiation. In this way, space and cost can be saved, which makes the apparatus very suitable for small and battery-powered mobile apparatus, like a mobile phone, a hand-held computer, a laptop computer, etc.