Optical properties of polystyrene black dyed microspheres

The light absorption cross section is one of the most important optical properties along with the light scattering and the light extinction cross sections. The light scattering cross section when added to the light absorption cross section produces the light extinction cross section. Light absorption cross sections of polystyrene black dyed microspheres were measured by a multi angle absorption photometer (MAAP) together with the combination of a differential mobility analyzer (DMA) and a condensation particle counter (CPC). The MAAP is a filter based instrument that can measure light absorption properties without artifacts by using backward light scattering intensity measurements to compensate. Preliminary result for the 980 nm sized polystyrene black dyed microspheres depicts that the absorption cross section is about 1.5 × 10−14 m2 per sphere. In addition, the light absorption cross section of 233 nm and 10 μm spheres were measured. The near field scattering image data are shown for three polystyrene black dyed microspheres. The implication of the optical properties for the different sized black spheres is that the absorption coefficient and scattering image data depend on the size of the spheres.