Abstract: In an embodiment a sensor device includes a sensor element, a media supply configured to transport a medium to the sensor element and a surface, wherein the surface is configured to be exposed to the medium during operation of the sensor device, and wherein the surface comprises a surface structure configured to reduce a wettability of the surface by the medium.

Abstract: A double-core light-conducting fiber comprise a pump core, a laser core which is arranged centrically in the pump core, and a cladding surrounding the pump core. The pump core which is constructed with a substantially circular cross section has at least one ground portion on the outside which extends in the light direction of the double-core light-conducting fiber and amounts to 1% to 49% of the diameter of the pump core. A process for the production of the double-core light-conducting fiber and to a double-core fiber laser and to a double-core fiber amplifier are also disclosed which use the double-core light-conducting fiber according to the invention. The substantially round pump core with its centrically arranged laser core enables a simple connection with other fiber-optic components and a simple coupling in of the pumping light.