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Published on 22 March 2023

Developing components for quantum communications and computing

  What is Quantum Photonics?

  • Quantum photonics is key to ensure ultra-safe data transmission. It also has recently emerged as a potential path towards quantum computing.
  • Ensuring large-scale integration is necessary to enable quantum applications. To achieve massive integration, CEA-Leti leverages its mature Si and SiN photonics platform for the development of low-loss quantum photonic hardware.
  • CEA-Leti specifically develops quantum-grade photonic integrated components & circuits for the generation, fast encoding, coherent manipulation & detection of photonic qubits. CEA-Leti components are compatible with discrete or continuous variable approaches.


CEA-Leti's quantum photonics platform enables the development of next-generation technologies for key industries such as:

  • Finance
  • Health care
  • Energy
  • Telecommunications
  • Defense

   The goal 

  • CEA-Leti aims at contributing to the future generation of miniaturized ultra-secure quantum communication systems, either fiber-based or in free-space, by developing integrated quantum transmitter and receiver circuits matching the specifications of the most advanced quantum communication protocols, such as device-independent ones.
  • CEA-Leti also aims at contributing to the development of integrated quantum photonic processors relying for example on measurement-based quantum computing protocols. We address the heart of the programmable quantum processor while ensuring seamless generation of entangled photon cluster states and their high-efficiency detection on-chip.

Key facts 

State-of-the-art capabilities

  • Design, Process integration in 200/300mm, Test, Packaging

Versatile platform

  • Comprehensive library of mature components @ 1310 and 1550nm
  • Integration of new materials (NbN, LiNbO3…)

Record low optical losses

  • Si waveguides: 0.2-1.1dB/cm
  • SiN waveguides: 0.05dB/cm

What does it require? 

CEA-Leti's experts are developing key integrated components and circuits to enable advanced quantum key distribution protocols and quantum processing:

Single photon generation

  • Hybrid III-V/Si lasers delivering weak coherent pulses [1]
  • High-Q ring resonators delivering heralded single photons (currently MHz rate, targeting GHz rate) [2]

Photon fast encoding and coherent manipulation

  • Loss-free thermo-optic phase shifters
  • Fast phase shifters based on free-carrier plasma dispersion
  • Towards fast & low-loss Pockels phase shifters


Single photon detection

  •  HgCdTe avalanche photodiodes [3] with a world-record speed for the detection of mesoscopic photon states
  • Optimized NbN material [4] for superconducting nanowire single photon detectors with high efficiency and low dark counts
  •       FLYER


1. C. Agnesi et al., Hong-Ou-Mandel interference between independent III-V on silicon waveguide integrated lasers,
Opt. Exp. 44, 271 (2019)

2. H. El Dirani et al., Low-loss silicon technology for high-Q bright quantum source, proc. of IEEE Group IV Photonics
Conference (2019)

3. J. Rothman et al., Meso-photonic detectionbwith HgCdTe APDs at high-count rates, J.of Electron. Mat.,
s11664-020-08461-8, 2020

4. R. Rhazi et al., Improvement of critical
temperature of niobium nitride deposited on
8-inch silicon wafers thanks to an AlN buffer layer, Superconduct. Sc. and Technol. 34, 045002 (2021)