Optical Interferometric and Dual Wavelength Photometric Tomographic Methods

Dieter Mewes, Kerstin Kling

Institut für Verfahrenstechnik, Universität Hannover, Germany Callinstraße 36, D-30167 Hannover, Germany, e-mail: dms@c36.uni-hannover.de

ABSTRACT

Several optical tomographic methods are described that are used for the visualization of temperature and concentration fields. The applications are limited to optical transparent fluids and visible light with 400nm to 700nm wavelength. The measurements are done by interferometry or intensity sensoring. The results are given as integral information along the length of a particular pathway of the light. The physical properties measured are changes of the refractive index due to the density field or changes of the light intensity due to changes of the absorption coefficient. Tomographic reconstruction is used to obtain from the integral measurements instantaneous information about the local values of the field function in each cross sectional area of a volume under investigation.

Keywords Optical tomography, absorption and interferometric methods, limited view reconstruction algorithms, mixing processes