Efficient single-photon extraction from quantum-dots embedded in GaAs micro-pyramids

摘要

We demonstrate an easy method to fabricate efficient single-photon sources based on In(Ga)As quantum-dots embedded in reversed GaAs micro-pyramids. It relies on a single wet-chemical etching step utilizing an AlAs sacrificial layer. Due to the pyramidal shape of the cavities, we have been able to separate a small number of quantum-dots from the self-assembled ensemble and improve the extraction efficiency for single photons. The latter is predicted by finite difference time domain and finite elements method simulations to be about 80%-90% over a broad spectral range of 40 nm. Single-photon emission has been proven experimentally by means of auto-correlation measurements.