3D electronic confinement in semiconductor nanostructures (« quantum dots », QDs) produces a quantized energy structure and leads to physical effects similar to those commonly observed in atomic systems.

The use of QDs in the active region of semiconductor lasers leads to distinctive device properties, including a reduced transparency current, lower temperature sensitivity and tunable gain-phase coupling. On the other hand, the optical recombination of excitonic states in single QDs produces nonclassical states of the electromagnetic field with a well- defined number of photons – such “single-photon sources” can be applied in quantum communication.

In this talk, after a brief introduction on the growth and optical properties of QDs, I will review the physics and potential applications of QD lasers and single-QD devices. In particular, recent work at EPFL on lasers, superluminescent diodes and single-photon sources in the wavelength region around 1300 nm will be described. The challenges of single-photon detection at telecom wavelengths will also be discussed, along with recent results on nanostructured superconducting single-photon detectors.


Seminar, 8th of March, 12:00h. Conference Room

Hosted by ICFO