Refractometry of organosilica microspheres

The refractive index of novel organosilica (nano/micro) material is determined using two methods. The first method is based on analysis of optical extinction efficiency of organosilica beads versus wavelength, which is obtained by a standard laboratory spectrometer. The second method relies on the measurable trapping potential of these beads in the focused light beam (laser tweezers). Polystyrene beads were used to test these methods, and the determined dispersion curves of refractive-index values have been found accurate. The refractive index of organosilica beads has been determined to range from 1.60 to 1.51 over the wavelength range of300-1100 nm