Numerical simulation of the optical interactions between transparent particles in the electromagnetic field of a laser beam.

Results are presented of near-field calculations for a bisphere positioned in the electromagnetic field of a laser beam by using the Mie-theory in con nection with the plane wave representation of an arbitrary field. The two p articles can be arranged in any way in the beam. There are no limits with r espect to particle size and position. Also the distance between the two par ticles may be differ. The optical interactions between the two particles ar e considered in detail by separating the dominating orders of scattered lig ht with the help of Debye-series. The numerical simulation of these interac tion effects is an important task to improve the measurement precision of P DA-applications for particle sizings in spray systems.