Detection and sensing

Nanophotonics enables the control of light-matter interactions on a nanoscale that is much smaller than the wavelength. This makes it possible to trap light in nanoresonators and enhance the efficiency of interactions with matter that would otherwise be very weak.

The team is exploring two avenues of research to improve the efficiency of active components and detection processes:

• Plasmonic resonators are of particular importance in the THz range. The objective of this thesis is to use so-called Helmholtz resonators, combined with 2D materials such as graphene, hBN, or MoS₂, to develop electrically tunable devices. In graphene, for example, applying a voltage can modify the Fermi level and thus alter its optical response. When combined with a plasmonic resonator, the modulation of the reflected or transmitted electromagnetic wave would be enhanced, enabling its use as a modulator. The resonator can also be used both to enhance the interaction with matter for broadband infrared spectroscopy and to amplify the photocurrent measured at the graphene interface, which would act as a detector.

   

• Certain biological objects, such as proteins, are particularly small (on the order of a few tens of nanometers), so they scatter very little light: observing them is extremely difficult without certain experimental techniques, such as labeling with fluorescent molecules, which inevitably affects the object being studied. Our team is studying so-called “label-free” methods, based on the iSCAT technique, which seeks to reconstruct images from the interference between a reference wave and the wave scattered by the particle. The scattered field can be enhanced by the presence of nanophotonic objects in its environment: this is the principle behind the CEISCAT method.

   

CURRENT AND FORMER MEMBERS

	Pierre-Louis Paillet Doctorant (PhD 2027) Active resonators coupled to 2D materials for detection and sensing in the THz range
	Matthieu Greffet Ingénieur de recherche UNVEIL
	Florian Semmer Post-doctorant (maintenant ingénieur de recherche chez UNVEIL)

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