Laser cleaning of solid surface: Optical resonance and near-field effects

The optical resonance within the transparent particle with size a similar to lambda (radiation wavelength) strongly influences the intensity distribution in the contacted area (substrate surface). As a result the efficiency of dry laser cleaning is a strong nonmonotonous function of the particle size. Another important effect is related to the interaction between scattered and reflected light of the particle on the surface (near-field effect). Examination of these effects is done within the frame of exact solution of the Light scattering problem. The distribution of absorbed intensity is the basic input characteristic for the laser cleaning model. It is used during solution of heat equation and equations of theory of the elasticity (thermal expansion and acoustic wave generation). This paper concentrates on the calculations of intensity distributions as a function of typical parameters in laser cleaning.