DS0708 -

Unconventional integrated nanophotonIc sources with quantum correlations – UNIQ

Submission summary

The integration of reliable quantum sources on a photonic microchip is at heart of intense research in today quantum photonics. The conventional pathways to achieve single photon sources rely on either III-V quantum dot technology or enhanced optical nonlinarities (four wave mixing) in silicon photonics. The former approach requires cryogenic temperatures, and its integration on a silicon chip at the telecom band remains challenging. The latter, on the other hand, operate at room temperature, but even if the efficiency of such integrated sources can be improved by spatial multiplexing, compactness and scalability remain open issues.

UNIQ proposes a new paradigm to tackle single and quantum correlated photon generation using nonlinear III-V semiconductor materials (both passive and active) in optical nanocavities. In essence, our project is devoted to the realization of unconventional quantum correlated photonic sources based on nonlinear interactions in coupled nanocavities with few photons. Unlike conventional semiconductor quantum sources that require deterministic coupling of cavity modes to single nanoemitters (i.e. quantum dots) and operate at ultralow temperatures, UNIQ sources will achieve quantum correlations with few photons using optical nonlinearities at room temperature from uniformly grown materials (bulk, quantum wells) in coupled nanocavities. Such capabilities will rely on two recent paradigms in nonlinear coupled cavity systems: i) the generation of photon antibunching by means of the so-called unconventional photon blockade (UPB) mechanism; ii) nonlinear transitions with low photon numbers, such as spontaneous symmetry breaking (SSB) in coupled nanolasers. These two mechanisms result from the interplay between third order optical nonlinearities and photon dynamics in optical cavities.

In UPB, weak nonlinearities are combined with photon tunneling between adjacent cavities to produce destructive interference and hence suppression of multi-photon states. As a result, strong photon antibunching has been predicted in the transmission of a resonant coherent beam.
On the other hand, nonlinear optical transitions such as SSB give rise to strong photon localization, as recently demonstrated in coupled nanolasers. In this case, in contrast with UPB, nonlinearities are strong: the nonlinear shift of the laser frequency is large enough to overcome mode splitting. This has been shown to take place with only 100 intracavity photons, which can be further reduced for increased spontaneous emission factor of the nanocavities. Within SSB conditions, strong photonic correlations are theoretically predicted between output photons from both cavities.

The photonic platform that will used to realize the coupled cavity systems are photonic crystal nanocavities, which enable a large parameter space to tailor both strong and tunable evanescent coupling, high quality factors, ultra-small mode volumes, efficient input/output light coupling and large spontaneous emission factor nanolasers. Such a platform is compatible with device integration on a photonic microchip, small foot print and scalability.
Specifically, building blocks will be hybrid III-V semiconductor photonic crystal nanocavities and nanolasers on silicon, fully compatible with dense photonic integration on a CMOS microchip. Fabrication will be undertaken at LPN clean room, using the mature III-V photonic crystal nanotechnology and heterogeneous integration of III-V semiconductors on silicon.

To sum up, UNIQ seeks advanced quantum functionalities of III-V semiconductor nanosources at the interface between quantum optics and nanophotonics. It brings together worldwide-major actors in the quantum optics domain (LKB and MPQ partners) and nanophotonics (LPN). UNIQ proposes innovative technological developments that will ultimately enable room-temperature, single photon sources in the telecommunication C-band, with a high potential for integration.

Project coordination

Alejandro Giacomotti (Laboratoire de Photonique et de Nanostructures)

The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.


LPN Laboratoire de Photonique et de Nanostructures
LKB Laboratoire Kastler Brossel
MPQ Laboratoire Matériaux et Phénomènes Quantiques
LPN (CNRS DR IDF SUD) Laboratoire de Photonique et Nanostructures

Help of the ANR 526,054 euros
Beginning and duration of the scientific project: November 2016 - 42 Months

Useful links

Explorez notre base de projets financés



ANR makes available its datasets on funded projects, click here to find more.

Sign up for the latest news:
Subscribe to our newsletter