Tight Focusing of Light

Abstract

The effects of various properties on the tight focusing of light are considered. In particular, polarization of the incident field is an important consideration. Plots are presented for the variations in the focal intensity, and the area and volume of the focal spot, with numerical aperture. We consider Bessel beams, focusing with a system of circular pupil, and 4Pi focusing by a pair of opposing high-numerical-aperture lenses or a single paraboloidal mirror.

Keywords

• diffraction theory
• polarization
• laser beam shaping
• trapping
• materials processing
• optical recording