In the deep ultra-violet (DUV) and the mid infra red (MIR) regions of the spectrum, the so-called Hollow Core
Waveguide (HCW) is an alternative for light-delivery systems. In addition to efficient light transportation, the HCW can
be used as an intrinsic sensor: due to the long path-length through the HCW the spectral absorption of the gas under test
can easily be monitored. Based on preliminary studies, the UV-region from 170 nm up to 250 nm seemed to be a very
attractive alternative for gas-analyses, in comparison to the IR-region with the well-known gas-absorption bands. Using
improved and adjusted components, the existing system for UV-spectroscopy was optimized. The new system will be
described in details. Especially, the time-response using an external gas-feeding system is an additional parameter of the
studies. Within the spectral range of the new CCD-array spectrometer from 175 to 210 nm, highly structured spectra
have been determined, with a spectral resolution of less than 50 pm. In nitrogen, selected gases with extremely low
concentrations in the order of 1 ppm have been measured; the absorption spectra are compared to those from IR
measurements, using the HCW approach, too.
In the DUV-region and MIR-region, the so-called Hollow-Core-Waveguide is an alternative for light-delivery systems, because flexible silica-based fibers are no lnoger useable due to the high intrinsic absorption of silica. In additionl to light-transportation, only the HCW can be used as an intrinsic sensor: due to the long path-length through the HCW with similar intensity profiles at the input and output, the spectral absorption of the gas under test can easily be monitored. Up to now, the gases are analyzed in the MIR-region, mainly. However, the UV-region offers a lot of advantages. Using commercially available components for the UV-light source and the detector-system, the whole system with UV hollow-core-waveguides has to be studied in the wavelength-region from 170 nm up to 350 nm. With this experimental system, it is obvious to observe the UV-absorption of air and carbon dioxide below 200 nm, using nitrogen as a reference gas. In addition, ozone generated by the deuterium-lamp itself and several gas mixtures (e.g. 2 ppm toluene or xylene in cabon dioxide) were studied in detail.