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Microorganisms, such as bacteria, which might be present as contamination inside an industrial food or pharmaceutical clean room process need to be identified on short time scales in order to minimize possible health hazards as well as production downtimes causing financial deficits. Here we describe the first results of single-particle micro-Raman(More)
Fast analysis of bioaerosols in clean room environments is necessary in order to prevent contamination of pharmaceutical products, minimize machine downtimes, or both. The detection and identification of microbes will be carried out in several steps: After impaction of the aerosol on a surface, the particles are presorted with glancing light illumination(More)
A highly versatile setup, which introduces an optical gradient trap into a Raman spectrometer, is presented. The particular configuration, which consists of two lasers, makes trapping independent from the Raman excitation laser and allows a separate adjustment of the trapping and excitation wavelengths. Thus, the excitation wavelength can be chosen(More)
A technique for the determination of size changes of gas bubbles by means of Fabry-Perot resonances in elastic light backscattering and optical trapping is presented. A theoretical description of the interaction of a strongly focused laser beam with gas bubbles is also given. The differences in elastic light scattering for particles with a relative(More)
Raw materials need to be of a certain quality with respect to physical and chemical composition. They also need to have no contaminants in the form of particles because these could get into the product or indicate the raw materials are not pure enough to make a good quality product. When particles are found, it is important to identify their chemical and(More)
During the slow evaporation of an optically levitated microdroplet of a glycerol-water mixture (3:1) (approximately 12.44 µm in radius) several morphology-dependent input resonances have been observed in its Raman spectrum. These resonances yield sudden temperature jumps of approximately 10 °C in the microdroplet as evidenced by sudden shifts in the output(More)
The applicability of a UV micro-Raman setup was assessed for the rapid identification of fibrous asbestos minerals using 257 and 244 nm laser light for excitation. Raman spectra were obtained from six asbestos reference standards belonging to two basic structural groups: the serpentines (chrysotile) and the amphiboles (crocidolite, tremolite, amosite,(More)
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