Abstract

An apparatus for direct determination of the spectrally resolved scattering phase function of suspensions and emulsions is described. The system has a polychromatic xenon lamp as light source and a spectrometer as detector. In combination with a stepper motor the system enables sepctrally and angularly resolved measurements in the range of 450 nm to 950 nm and 10° 170°, respectively. A post processing algorithm, which takes the light propagation inside the cuvette within the regime of single scattering and the spectral dimension into account, was developed. This allows a direct determination of the scattering phase function for the indicated spectral and angular range. By comparing measurements on polystyrene microspheres with Mie theory the concept of the presented instrument was validated. Finally, the method was used to determine the scattering phase functions of different types and brands of soybean oil emulsions, a common phantom material in the field of diffuse optics.

© 2019 SPIE/OSA