A tunable microcavity

We present a generic microcavity platform for cavity experiments on optically active nanostructures, such as quantum dots, nanocrystals, color centers, and carbon nanotubes. The cavity is of the Fabry-Perot type with a planar back mirror and a miniature concave top mirror with radius of curvature similar to 100 mu m. Optical access is achieved by free beam coupling, allowing good mode-matching to the cavity mode. The cavity has a high Q-factor, reasonably small mode volume, open access, spatial and spectral tunability, and operates at cryogenic temperatures. Spectral and spatial tuning of the Purcell effect (weak coupling regime) on a single InGaAs quantum dot is demonstrated. (C) 2011 American Institute of Physics. [doi:10.1063/1.3632057]