Device for the excitation of a gas column enclosed in a hollow-core optical fibre

A device for excitation of a gaseous medium contained in a casing, with said device being coupled to said casing and arranged on the exterior of said casing, comprising:

• a microwave applicator adapted to create a lateral excitation in an interior of said casing over at least a portion of said casing, the microwave applicator being in a form of microstrip line comprising a ground plane, a dielectric layer, and a conducting line, with the hollow-core optical fiber being arranged between the ground plane and the conducting line, wherein
• the casing is a hollow-core photonic dielectric structure whose core has a diameter that is less than 300 μm and the microwave applicator makes it possible to create a surface wave that can create and confine a microplasma starting from a gaseous medium contained in the casing, said surface wave making possible creation of a surface wave having a tubular spatial distribution, coaxial to the hollow core, and whose intensity peak is localized at the interface between the microplasma and a periphery of the hollow core.