Transverse mode structure of hemispherical microcavities

The authors have studied the mode structure of planar-spherical cavities. They have developed the possibility of templating a gold coated surface with a regular array of spherical dimples. A planar gold plated glass sheet a few microns is placed above the surface, thus forming a regular array of planar-spherical cavities. These cavities, are reproducible and with a well defined and adjustable geometry: both the cavity length and the depth of the spherical mirror can be changed. Moreover, they can be filled with a variety of materials, either linear or nonlinear and may therefore be an excellent building block of novel macroscopic optical structures. In order to model light-matter interaction in these cavities it is essential to have a good understanding of the mode structure of a single empty cavity. This paper reports the experimental and theoretical analysis of the cavity modes.