Polarized metal/semiconductor sources based on confined Tamm plasmons

Plasmonic Tamm states are interface modes formed at the boundary between a distributed Bragg mirror and a metallic layer [1]. Their optical properties lie in between surface plasmons and microcavity photonic modes. In particular, the losses are reduced compared to a conventional plasmon. We will first describe some features of semiconductor quantum wells coupled to extended Tamm modes, like strong coupling with the excitons and lasing under optical pumping [2,3]. The main advantage of the Tamm modes lies in the easy confinement of the mode which can be obtained only by structuring the metallic part of the structure [5]. We will show that confined Tamm plasmon modes can be advantageously exploited for the realization of new kind of metal/semiconductor lasers [6]. Laser emission is studied for Tamm structures with various diameters of the metallic disks which provide the confinement. A reduction of the threshold with the size is observed. The competition between the acceleration of the spontaneous emission and the increase of the losses leads to an optimal size, which is in good agreement with calculations (Fig. 1). The easy control of the mode properties offered by the patterning of the metallic layer can be applied to the control of the polarization of the emission. This effect will be discussed in the case of asymmetrical confined Tamm lasers.