Single photons from a whispering gallery resonator

21.06.2013, 00:00

Newsletter 6

The quantum state of a single photon is among the most fundamental and intriguing manifestations of quantum physics. The implementation of a source of single photons with adjustable spectral properties is pursued by many physicists around the world. Such a source could be used to carry out experiments on the single-photon level on interactions with atoms and molecules, as well as with other single photons. We have experimentally demonstrated a versatile single photon and photon-pair source based on the physics of whispering gallery resonators. A disk-shaped lithium niobate resonator, monolithic and intrinsically stable, generates pairs of entangled photons when excited with green laser light. These photon pairs can be used as a source of heralded single photons. The whispering gallery resonator also allows the central wavelength of the photons to be tuned from the visible to the infrared wavelength regime, and their bandwidth to be varied from 7 to 13 MHz.

Contact: josef.fuerst(at)mpl.mpg(dot)de
Group: Leuchs Division
Reference: M. Förtsch et al., Nature Commun. 4, 1818 (2013).