Return to Research

Quantum Optics

We develop novel tools and techniques to generate quantum light states and arbitrarily manipulate and characterize light at the single-photon level. This allows us to perform experiments that test the very foundations of quantum mechanics and pave the way to emerging quantum technologies.

Our group is a world leader in the production, manipulation, and detection of quantum states of light in the continuous-variable regime based on the interaction of ultrashort laser pulses with non-linear crystals. Novel conditional preparation techniques allow the controlled production of single photons and of basic quantum operations like the addition and subtraction of single photons from arbitrary light states. Arbitrary sequences and superpositions of such operations, together with a highly advanced scheme for time-domain homodyne detection and quantum tomography, are used both for the analysis of fundamental quantum physics, and as a tool for possible applications in the emerging fields of quantum communication and information processing.

Some recent achievements include the realization of the highest fidelity noiseless amplifier for quantum light states and the production of hybrid quantum-classical entanglement.

Original techniques have been developed for the remote preparation of quantum state superpositions in separated temporal modes and homodyne detection of non-classical states in arbitrary spectro-temporal modes, which may represent an efficient novel approach for encoding quantum information in a high- dimensionality Hilbert space. In this case, adaptive techniques typical of ultrafast coherent control physics have been applied for the first time to measure nonclassical states of light.

Our main tools:

  • Quantum state generation via parametric down-conversion
  • Heralded single-photon generation
  • Heralded quantum operators (photon creation and annihilation)
  • Operator sequences and superpositions
  • Quantum state analysis by homodyne detection and quantum tomography
  • Ultrashort pulse shaping and characterization

Our main research topics:

  • Generating tailored quantum states and operators
  • Testing the fundaments of quantum mechanics (commutation rules, etc.)
  • Providing the basic resources for novel quantum technologies