Submicron Optics and Nanosensors
OSNC activities are at the interface between photonics and nanosciences department. The 3 main thematics listed below are led with strong interaction in between.
- Nanophotonics and plasmonics (G. Colas des Francs, J.C. Weeber, A. Bouhelier, K. Hammani, J. Arocas)
- Plasmonics and optics for biosensing (E. Finot, T. David, A. Dereux, A. Leray, L. Markey)
- Tomography, topography and chemical investigation applied to materials (L. Lesniewska, E. Bourillot, Y. Lacroute)
Head Group -Nano
Phone : +33 (0)3 80 39 60 26 / 03 80 39 60 34
Head Group -Photonics
Phone : +33 (0)3 80 39 90 67
Specific actions aiming at the development of plasmonics for datacom applications (denoted as integrated plasmonics) are conducted. Plasmonics can be viewed as a disruptive approach of optical communication at the chip scale, in the sense that it uses non-conventional wave guided modes with specific properties such as high field confinement. Those activities are at the origin of synergies developed between researchers dominantly involved into telecom fields and integrated plasmonics. The main objective of those collaborative actions is to push plasmonics beyond fundamental aspects to the level of applications for optical routing and/or reconfiguration. In this context, specific plasmonic modes sustained by Dielectric Loaded Surface Plasmon Waveguides (DLSPPWs) comprising a dielectric ridge (most often a polymer) deposited onto a metallic stripe have been found to be of interest for thermo-optical applications [Hassan et al, Appl. Phys. Lett. 99, 241110 (2011)] and integrated polarization conversion [Hassan et al, Opt. Lett. 39, 697 (2014)].
Radio-frequency antennas are ubiquitous in today’s communication-driven society. They are embedded in nearly every technological devices ranging from the last generation of smartphones to anti-counterfeit identification tags. Part of our activity is to extend the concept of communication antenna in the optical domain in order to drastically reduce the footprint of the transponders down to the nanoscale. We are developing a new generation of electrically connected functional optical antennas enabling a plasmon-mediated dual transduction between electrons and photons. This concept provides a novel approach where, at the nanoscale, the light source and the detector are integrated into a single metallic structure, superseding complex hetero-designs and paving the way for developing a short-range optical wireless link. At the core of the design is an atomic-scale tunnel gap whereby optical rectification or inelastic tunneling can reciprocally mix photons and electrons [Stolz et al. NanoLetters, 14, 2330 (2014)]. A particularly interesting property of optical antennas is their ability to concentrate and enhance an incident electromagnetic field. We have used this unique asset to develop nonlinear frequency conversion nanoscale device [Berthelot et al. Opt.Express, 20, 10498 (2012) ; Demichel et al. Opt. Express, 22, 15088 (2014)]. We are interesting at comprehending the linear and non-linear responses of the nanoscale device.
We are interested in transposing the concepts of cavity quantum electrodynamics (cQED) into plasmonics.
This would ensure a better understanding of the light-matter interaction at the nanoscale and should permit to adapt optical microcavity devices (e.g. low threshold laser, photon blockade, cavity nonlinear optics) to nanophotonics. We notably extended the definition of the Purcell factor, e.g. Q/V where Q is the quality factor and V the modal volume, to describe the coupling of an emitter to a plasmonic waveguide [Barthes et al Phys. Rev. B, 84, 073403 (2011)]. Surface plasmons polaritons (SPP) are a promising alternative to optical microcavities with high quality factor for light matter-interaction at the nanoscale, down to the single atom-single photon level, owing to their sub-wavelength modal volume, albeit at the price of low quality factor. In addition, we also define the plasmonic Purcell factor near a metal nanoparticle, taking into account exactly the losses [Derom et al , EPL 98, 47008 (2012)] . All these works extend cQED concepts to localized and delocalized SPP, participating to the development of quantum plasmonics and the so-called cavity-less quantum electrodynamics, where the mode confinement is an intrinsic property of SPP [Colas des Francs et al, J. Opt., 18, 094005 (2016).].
The plasmonics at the nanoscale has recently benefited from a new collaboration between the Photonic Dept. and the Quantum Interactions and Control Dept. at ICB. In this context, an original formalism based on an effective Hamiltonian that exactly transposes cavity QED concepts into plasmonics is developed [Dzsotjan et al, PRA 94, 023818 (2016), Rousseaux et al, PRB 93, 045422 (2016)]. We notably investigate the strong coupling regime and explicitly describe the hybridization between the localized plasmons of a metal nanoparticle and the excited state of a quantum emitter, offering a simple and precise understanding of the energy exchange in full analogy with cavity quantum electrodynamics treatment and a dressed atom picture (Varguet et al, Opt. Lett. 41, 4480 (2016)].
On this basis, we now plan to propose, design and characterize original nanophotonics components, plasmonics analogous (at the submicronic scale) of optical microcavities.
- Plasmonics sensors
- Nanometrics characterization