The invention relates to a substrate (SUB) serving as a support, an optical waveguide (OWL) disposed on the substrate (SUB) and electrical conduction paths (ELB). Conventionally, the electrical conduction paths are placed on a thin insulating layer covering the substrate. According to the invention, the electrical conduction path (ELB) are routed on top of the surface (WOF) of the optical waveguide (OWL). This provides an improved insulation of the electrical conduction paths (ELB); moreover, the substrate surface is better utilized. Preferably, the electrical conduction paths (ELB) which are placed in ramp-like recesses (RA), are routed from the substrate surface (SOF) upwards to the surface (WOF) of the optical waveguide (OWL). The invention can be employed most advantageously proximate to laser bars where several conduction paths which are combined to form coplanar electrical waveguides, are arranged in a tight space.