A theoretical analysis is given for the near-field images of a monolayer of periodically arrayed dielectric spheres, obtained by monochromatic external light. Depending on the frequency and the incident angle of exciting light, the near-field intensity exhibits a large enhancement due to the resonant excitation of photonic bands with two-dimensional band dispersion. The various near-field patterns, sometimes quite unlike the image by natural light, are shown to occur and are analyzed using the plane-wave amplitudes of excited Bloch waves. The resonant pattern is well understood by the group-theoretical characters of photonic bands. Also, an analytical expression is given for the field in the long wavelength limit, which can reproduce all the numerical characteristics quite successfully. Especially, it can explain why the near-field image becomes ω independent, while the reflectivity varies as (Formula presented).
|Number of pages||18|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 1998|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics