Integrated sensor head for gas analysis via atomic emission spectroscopy

We report about design, fabrication, and experimental characterization of a compact sensor head for gas analysis via atomic emission spectroscopy. The novelty of our approach is the integration of a micro-hollow cathode structure for plasma generation and an optical collector on a common planar micro systems platform. The sensor head is designed for a fiber optic spectrometer. Elliptically-shaped reflector segments are used for the plasma-to-fiber imaging. A demonstrator was fabricated by use of ultra-precision machining techniques. Experimental tests show an improved optical coupling efficiency and a sensitivity in the ppb range for the detection of CCI₂F₂ in He.