A feasibility study using an ion mobility spectrometer coupled with a multi-capillary column (MCC) was started to identify characteristic peaks of volatile compounds in exhaled human breath samples ...of 10 ml volume. The breath of 20 patients with sarcoidosis and suspicion of sarcoidosis because of mediastinal lymph node enlargement was investigated. Using a set of procedures for data processing and scoring a sector of interest was determined within the IMS-chromatogram. It could be shown that a procedure related to a single peak in the IMS-chromatogram delivers differentiation into the two groups of patients with confirmed sarcoidosis and those suffering no sarcoidosis. The potential biomarker is characterized by the following parameters: inverse mobility (1/K(0)) 0.53 ± 0.01 V s cm(-2)-retention time 22 ± 5 s. These results are a first step in breath analysis by MCC/IMS in patients with sarcoidosis by an automated procedure applied to IMS-chromatograms directly.
The realization of ultra low-loss dielectric reflection gratings with diffraction efficiencies between 7% and 0.02% is presented. By placing the grating beneath the highly reflective layerstack ...scattering was significantly reduced. This concept allows the all-reflective coupling of high laser radiation to high finesse cavities, thereby circumventing thermal effects caused by absorption in the substrate.
We designed and fabricated an all-reflective 50/50 beam splitter based on a dielectric grating. This beam splitter was used to set up a power-recycled Michelson interferometer with a finesse of about ...FPR ≈ 880. Aspects of the diffractive beam splitter as well as of the interferometer design are discussed.
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