INPHYNI seminar: Nathan Lecaron --- Floriane Pellerin

On-chip Quantum Key Distribution with Decoy States in Silicon Photonics (N. Lecaron)

Abstract:
With the rise of quantum computing, widely used public-key cryptography is expected to become vulnerable, as it relies on computational hardness assumptions. Quantum Key Distribution provides an alternative security paradigm based on the laws of quantum physics, offering information-theoretic security. In particular, the BB84 protocol with decoy states enables secure key exchange using realistic photon sources.
This work presents the implementation of a high-speed decoy-state BB84 QKD protocol on a compact silicon photonic chip. The goal is to move from bulky optical setups to scalable, integrated, and efficient quantum communication systems operating at high secret-key rates on a chip-scale platform.


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Femtosecond laser structuring of dielectric nanoparticles contained in optical fibres (F. Pellerin)

Abstract:

New types of optical fibre containing dielectric nanoparticles with enhanced scattering properties have attracted significant interest for use in distributed optical fibre sensors. The scattering performance of these fibres depends on the characteristics of the nanoparticles. Therefore, it is crucial to control their properties as precisely as possible. To this end, we propose to use a femtosecond laser that is tightly focused on the core of the optical fibre where the nanoparticles are located. Using this method, we will demonstrate that nonlinear absorption of the laser beam induces localised heating, thereby altering the properties of the nanoparticles