High Extraction Efficiency Source of Photon Pairs Based on a Quantum Dot Embedded in a Broadband Micropillar Cavity

Phys Rev Lett. 2022 Jul 15;129(3):033601. doi: 10.1103/PhysRevLett.129.033601.


The generation of photon pairs in quantum dots is in its nature deterministic. However, efficient extraction of photon pairs from the high index semiconductor material requires engineering of the photonic environment. We report on a micropillar device with 69.4(10)% efficiency that features broadband operation suitable for extraction of photon pairs. Opposing the approaches that rely solely on Purcell enhancement to realize the enhancement of the extraction efficiency, our solution exploits a suppression of the emission into the modes other than the cavity mode. Furthermore, the design of the device can be further optimized to allow for an extraction efficiency of 85%.