Surface emitting thermally assisted polaritonic light-emitting device

Abstract

We report a mid-infrared surface-emitting electroluminescent device operating in the strong coupling regime between light and matter. The structure is semiconductor based and can operate in absorption or—upon current injection—in emission. The observed minimum Rabi splitting at room-temperature is of the order of 15% of the bare transition. The polaritonic electroluminescence matches the polaritonic branches as measured in absorption and it tunes in frequency with the emission angle, covering a wide spectral range from 900 cm−1 to 1300 cm−1. The emitted light is mostly transverse-magnetic polarized, but its intensity increases with increasing temperature. This finding suggests a thermally assisted emission process. A simple model that takes into account both the contributions reproduces the data fairly well. This grating-based, surface-emitting resonator architecture suits the future study and development of electroluminescent intersubband devices operating in the strong-coupling regime between light and matter.