Emitters based on semiconductor quantum dots are promising sources for both single photons and pairs of polarization-entangled photons. Typically, single photons are generated through a photon emission event bringing the electronic system from a single-exciton state back to the ground state. In the case of entangled photons two photons are generated through a cascaded emission from the biexciton to either one of the single-exciton states and then back to the ground state. Alternatively, emission of two photons can also be achieved through a higher-order two-photon process bringing the quantum dot directly from the biexciton state (through a virtual intermediate state) back to the ground state. Here we discuss in particular how this two-photon process can lead to certain conceptual advantages in both the generation of polarization-entangled photon pairs and generation of single photons.

Date Published: 14 March 2013
PDF: 6 pages
Proc. SPIE 8623, Ultrafast Phenomena and Nanophotonics XVII, 86230E (14 March 2013); doi: 10.1117/12.2004191

Published in SPIE Proceedings Vol. 8623:
Ultrafast Phenomena and Nanophotonics XVII
Markus Betz; Abdulhakem Y. Elezzabi; Jin-Joo Song; Kong-Thon Tsen, Editor(s)