Qscale Quantum technologies for extending the range of quantum communications

Video paper in JOVE

Efficient quantum state engineering of light

Engineering non-classical states of light is a central quest for quantum optics. Beyond their fundamental significance, such states are the resources for implementing a variety of protocols, ranging from enhanced metrology to quantum communication and computing.

The team led by J. Laurat at Laboratoire Kastler Brossel has recently demonstrated very efficient techniques to generate such states with optical parametric oscillators. These sources are based on non-linear crystals inserted inside optical cavities, and can generate pair of photons or squeezed light. Noise reduction by more than 90% below the shot noise level has been obtained. By adding to these initial resources single-photon detections operated by superconducting detectors, Fock states (single photon or two-photon) and optical Schrödinger cat states have also been generated with unprecedented fidelities. The well-controlled spatiotemporal mode in which they are produced will facilitate their use in subsequent protocols where such states need to interfere with other optical resources, e.g. in quantum gate implementations or cascaded state-engineering procedures.

These experiments are summarized in a video article, published in JoVE - Journal of Visualized Experiments.