A fully tunable microcavity

Date: 
Monday, March 1, 2010 -
4:00pm to 5:00pm
Speaker: 
Russel Barbour
Speaker's Institution: 
University of Oregon

 

Semiconductor optical microcavities that combine high Q-factors with a small  mode volume play a vital role in modifying the interaction between light and  matter. Several interesting phenomenon arise when an emitter is introduced into  such a cavity. These include enhancement or suppression of the spontaneous  emission rate (weak coupling) and normal mode splitting (strong coupling).  The majority of successful microcavity experiments have been performed on self-- assembled quantum dots. For quantum dots the work-horse cavity geometries  are micropillars, photonic crystals and whispering gallery devices. However these  devices lack in situ spatial tuning and offer only very limited spectral tuning. Over  coming these challenges is crucial for maximizing the interaction between light and matter.
In this seminar I will present the development of a miniaturized, fully tunable Fabry-Perot type microcavity for quantum dot microcavity experiments. The  cavity has demonstrated high Q-factor modes (Q ~ 104), presently limited only  by the quality of the coatings. The relatively high Q-factor is obtained by using a  miniaturized spherical mirror which laterally confines the optical mode. We have  demonstrated unprecedented in situ control over a single quantum dot within the  cavity, spatially positioning the dot at the exact anti-node of the cavity electric field,  hence maximizing the interaction between light and matter. Spectral and spatial  tuning of a single dot Purcell effect has been demonstrated.