Light scattering from micron-size fibers*

Exact theoretical expressions for scattering of light incident at oblique angles on a cylinder are derived and compared with measurements on aluminized quartz fibers (diameters 0.9–2.2 μm) using a He-Ne laser. The free-electron gas model was used for the dielectric response function for Al. Fitting the angular positions of observed maxima and minima in the scattered intensity to the calculated values gave a sensitive method for determining fiber radii, reproducible within ± 3%–5%. These radii agreed with values from Fraunhofer diffraction at normal incidence within ± 10%–15%. The role of surface plasmon excitation in the scattering of light from cylinders is discussed briefly.