TY  - JOUR
A1  - Schael, Frank
A1  - Reich, Oliver
T1  - In-situ-Analytik heterogener Medien mit frequenz- und leistungsmodulierten Diodenlasern
N2  - Electronic intensity and frequency modulation of diode lasers enables new perspectives for highly sensitive analytical in-situ techniques. For analyis of "heterogeneous" media, which may consist of coexisting gaseous, liquid, and solid phases and often show multiple light scattering, non-invasive techniques with outstanding performance characteristics can be developed. Analysis of photon density waves launched by intensity-modulated lasers provide an elegant way for the determination of absorption and scattering coefficients of multiple scattering media. The absorption coefficient can be used for qualitative and quantitative analysis of chemical constituents (which absorb in the range of the laser wavelengths). The scattering coefficient allows characterization of physical and morphological properties of the sample. In the current work, applicability of appropriate radiation transport models was investigated with simple light scattering solutions and compared with results obtained from the treatment according to the theory of Kubelka and Munk. Measurements of human blood samples are discussed. A new method for determination of water vapor partial pressure in a polyurethane foam with a frequency-modulated external cavity diode laser is discussed.
Y1  - 2001
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/17976
ER  -