Chapter 7 - Near-field optical structuring and manipulation based on local field enhancement in the vicinity of metal nano structures

Abstract

The chapter discusses near-field optical structuring and manipulation based on local field enhancement in the vicinity of metal nanostructures. Three optical effects and phenomenon related to MNSs are considered for near-field optical lithography (NFOL) and manipulation, including local plasmon resonance, electromagnetic singularity, and nanometer scale optical forces. While the scattering term is weak for nanometer-sized particles, the gradient force term is expected to be strong because of the high-field gradients characteristic of evanescent fields. In the case of a semi-infinite tip, dipolar plasmon resonance should be in the far infrared where the photosensitive materials generally do not absorb electromagnetic radiation. Lateral tip resonance could be excited in the visible but in that case, the field is not confined at the tip end but on the contrary, at its edges. Following on from the classical far-field optical lithography, TEOL is carried out on photopolymers by several groups. The mask-based surface plasmon lithography is also elaborated in the chapter.