Observation of light scattering from nonspherical particles using optical levitation

The optical levitation technique has been extended to the study of light scattering from several basic types of nonspherical particles such as spheroids; spherical doublets, triplets, and quadruplets; and spheres within spheres. Individual particles were assembled in air using two independently maneuverable laser beams and then held at rest in the beam in fixed orientation. Observations were made of the light scattering in the near and far field with high resolution. Other applications of the technique are envisaged.