Applications of lead-salt microcavities for mid-infrared devices

Optically pumped lasers and light detectors based on microcavities with highly efficient Pb_1-xEu_xTe/EuTe Bragg interference mirrors are described for the 3-6 μm wavelength range. The lasers operate up to and above room temperature with a minimum pump intensity threshold of about 15 kW/cm² The responses of the photodetectors show well pronounced cavity resonances. Furthermore, a microcavity is used to determine the absorption spectrum of a superlattice containing three-dimensionally ordered, self-organised PbSe quantum dots. The quantum dot absorption peak, with a width of only 9 meV, confirms the exceptionally high homogeneity of the quantum dot size distribution, observed so far only for these lead-salt quantum dots.