Photon echoes from (In,Ga)As quantum dots embedded in a Tamm-plasmon microcavity

Abstract

Tamm resonators are an alternate type of cavities, in which the light-matter interaction may be significantly enhanced, as required for many applications in photonics or optoelectronics. A Tamm resonator comprises at least one metal layer as mirror, in the present case combined with a distributed Bragg reflector. The metal layer may turn out to be useful, for example, for injecting carriers or applying an electric field. Here, the authors use photon echoes in the exciton four-wave mixing signal to demonstrate that the studied Tamm resonator, which contains quantum dots as the optically active medium, allows one to perform coherent manipulations on quantum-dot excitons at power levels more than one order of magnitude lower than those required for bare quantum dots. This occurs despite the moderate quality factor of about 100. Moreover, it speeds up the radiative decay of the excitons by a factor of two (the so-called ``Purcell effect''). On the other hand, the coherence of the quantum dot exciton, which may become compromised by plasmon excitations in the metal, is hardly shortened. These results demonstrate that Tamm resonators are indeed prospective candidates for performing coherent optical manipulations.