Strain tuning of the properties of quantum dots microcavity systems

Scalable quantum photonic architectures demand highly efficient, high-purity single-photon sources. Among different kinds of quantum emitters, epitaxially grown self-assembled quantum dots (QDs) have been shown as one of the leading candidates for an efficient single-photon generation. In order to maximize the number of photons extracted from the device, QDs are frequently embedded into photonic structures such as micro-cavities. Once the QD is positioned inside an optical cavity, the Purcell effect ensures that light is emitted predominantly into the cavity mode. However, the exploitation of the Purcell effect requires careful spectral alignment of the QD emission and the cavity mode lines. Deterministic fabrication of microcavity devices yielded great improvements in the spatial and spectral alignment of the cavity resonance and the QD emission. However, spectral fine-tuning remains a necessary tool in order to overcome the remaining fabrication inaccuracies. We demonstrate single-photon sources based on an InAs quantum dot embedded in a versatile cavities structures, which is frequency tunable via externally-applied stress [1]. Our platform combines the
advantages of a microcavity and the piezostrain-tuning technique enabling single photon spontaneous emission enhancement via the Purcell effect and quantum dot with tunable wavelength. We also find that we can reversibly tune the polarization anisotropic splitting of the fundamental microcavity
mode.