Institut Langevin - Ondes et Images : Biophotonics

Our group is interested in the development of far-field optical techniques for the detection of biomolecules and nanoscale pollutants, as well as for the sub-wavelength imaging of cellular environments. In particular, we develop new approaches to super-resolution microscopy, plasmon-based optical biosensors and interferometric microscopy to detect viruses and image biological tissue. Furthermore, we investigate bioinspired self-assembly strategies for high-scale and low-cost nanofabrication techniques in photonics. For more information :
– Optical Antennas
– Super-Resolution Microscopy
– Full-field Optical Coherence Tomography

Recent publications

Achiral Magnetic Photonic Antenna as a Tunable Nanosource of Chiral Light Cui, L., X. Yang, B. Reynier, C. Schwob, S. Bidault, B. Gallas, and M. Mivelle ACS Photonics 10, no. 11, 3850-3857 (2023) Résumé: Sensitivity to molecular chirality is crucial for many fields, from biology and chemistry to the pharmaceutical industry. By generating superchiral light, nanophotonics has brought innovative solutions to reduce the detection volume and increase sensitivity at the cost of a nonselectivity of light chirality or a strong contribution to the background. Here, we theoretically propose a simple achiral plasmonic resonator based on a rectangular nanoslit in a thin metallic layer behaving as a magnetic dipole to generate a tunable nanosource of purely chiral light working from the UV to the infrared. This nanosource is free of any background, and the sign of its chirality is externally tunable in wavelength and polarization. These unique properties, resulting from the coupling between the incident wave and the magnetic dipolar character of our nanoantenna, coupled with a method of Fluorescent Detected Circular Dichroism (FDCD), shown to be 2 orders of magnitude more sensitive than classical circular dichroism measurements, thus provide a platform with deep subwavelength detection volumes for chiral molecules and a roadmap for optimizing the signal-to-noise ratios in circular dichroism measurements to reach single-molecule sensitivity.
A Magnetic Monopole Antenna Reynier, B., X. Yang, B. Gallas, S. Bidault, and M. Mivelle ACS Photonics 10, no. 9, 3070-3076 (2023) Résumé: Magnetic monopoles are hypothetical particles which, similar to the electric monopoles that generate electric fields, are at the origin of magnetic fields. Despite many efforts, to date, these theoretical particles have yet to be observed. Nevertheless, many systems or physical phenomena mimic the behavior of magnetic monopoles. Here, we propose a new type of photonic nanoantenna behaving as a radiating magnetic monopole. We demonstrate that a half-nanoslit in a semi-infinite gold layer generates a single pole of enhanced magnetic field at the nanoscale and that this single pole radiates efficiently in the far field. We also introduce an effective magnetic charge using Gauss’s law of magnetism, in analogy to the electric charge, which further highlights the monopolar behavior of this new antenna. Finally, we show that different plasmonic and metallic materials can provide magnetic monopole antennas covering the visible-to-near infrared range, even down to GHz frequencies. This original antenna concept opens the way to a new model system to study magnetic monopoles and a new optical magnetic field source to study “magnetic light-matter coupling.” Furthermore, it shows potential applications at lower frequencies, such as in magnetic resonance imaging.

Cellular structural and functional imaging of donor and pathological corneas with label-free dual-mode full-field optical coherence tomography Fei, K., Z. Luo, Y. Chen, Y. Huang, S. Li, V. Mazlin, A. C. Boccara, J. Yuan, and P. Xiao Biomedical Optics Express 15, no. 6, 3869-3888 (2024) Résumé: In this study, a dual-mode full-field optical coherence tomography (FFOCT) was customized for label-free static and dynamic imaging of corneal tissues, including donor grafts and pathological specimens. Static images effectively depict relatively stable structures such as stroma, scar, and nerve fibers, while dynamic images highlight cells with active intracellular metabolism, specifically for corneal epithelial cells. The dual-mode images complementarily demonstrate the 3D microstructural features of the cornea and limbus. Dual-modal imaging reveals morphological and functional changes in corneal epithelial cells without labeling, indicating cellular apoptosis, swelling, deformation, dynamic signal alterations, and distinctive features of inflammatory cells in keratoconus and corneal leukoplakia. These findings propose dual-mode FFOCT as a promising technique for cellular-level cornea and limbus imaging.
Optical transmission tomography (OTT) in health and disease: uniting micro and macro worlds Mazlin, V., S. Alhaddad, W. Ghouali, C. Baudouin, and A. C. Boccara Ophthalmic Technologies XXXIV 12824 (2024) Résumé: In this conference proceeding we illustrate an early concept of a new anterior eye imaging method - optical transmission tomography (OTT). Thanks to the 20× larger viewing area, OTT can enhance the precision of corneal cell/nerve density biomarkers compared to clinical specular and confocal microscopies. This holds promise for improving the selection of candidates for refractive surgery and for reducing the incidence rates of post-surgical dry eye, endothelial decompensation as well as other common complications.

Frugal random exploration strategy for shape recognition using statistical geometry Hidalgo-Caballero, S., A. Cassinelli, E. Fort, and M. Labousse Physical Review Research 6, no. 2 (2024) Résumé: Very distinct strategies can be deployed to recognize and characterize an unknown environment or a shape. A recent and promising approach, especially in robotics, is to reduce the complexity of the exploratory units to a minimum. Here, we show that this frugal strategy can be taken to the extreme by exploiting the power of statistical geometry and introducing different invariant features. We show that an elementary robot devoid of any orientation or location system, exploring randomly, can access global information about an environment such as the values of the explored area and perimeter. The explored shapes are of arbitrary geometry and may even nonconnected. From a dictionary, this most simple robot can thus identify various shapes such as famous monuments and even read a text.
Flexible implementation of modulated localisation microscopy based on DMD Illand, A., P. Jouchet, E. Fort, and S. Lévêque-Fort Journal of Microscopy (2024) Résumé: Localisation microscopy of individual molecules allows one to bypass the diffraction limit, revealing cellular organisation on a nanometric scale. This method, which relies on spatial analysis of the signal emitted by molecules, is often limited to the observation of biological objects at shallow depths, or with very few aberrations. The introduction of a temporal parameter into the localisation process through a time-modulated excitation was recently proposed to address these limitations. This method, called ModLoc, is demonstrated here with an alternative flexible strategy. In this implementation, to encode the time-modulated excitation a digital micromirror device (DMD) is used in combination with a fast demodulation approach, and provides a twofold enhancement in localisation precision. Layout: Nowadays, we can use an optical microscope to observe how proteins are organised in 3D within a cell at the nanoscale. By carefully controlling the emission of molecules in both space and time, we can overcome the limitations set by the diffraction limit. This allows us to pinpoint the exact location of molecules more precisely. However, the usual spatial analysis method limits observations to shallow depths or causing low distortion of optical waves. To overcome these restrictions, a recent approach introduces a temporal element to the localisation process. This involves changing the illumination over time to enhance the precision of localisation. This method, known as ModLoc, is showcased here using a flexible and alternative strategy. In this setup, a matrix of micrometric mirrors, working together with a fast demodulation optical module, is used to encode and decode the time-modulated information. This combination results in a twofold improvement in localisation precision.

3D-Architected Alkaline-Earth Perovskites Winczewski, J. P., J. Arriaga Dávila, M. Herrera-Zaldívar, F. Ruiz-Zepeda, R. M. Córdova-Castr, C. R. Pérez De La Vega, C. Cabriel, I. Izeddin, H. Gardeniers, and A. Susarrey-Arce Advanced Materials (2024) Résumé: 3D ceramic architectures are captivating geometrical features with an immense demand in optics. In this work, an additive manufacturing (AM) approach for printing alkaline-earth perovskite 3D microarchitectures is developed. The approach enables custom-made photoresists suited for two-photon lithography, permitting the production of alkaline-earth perovskite (BaZrO3, CaZrO3, and SrZrO3) 3D structures shaped in the form of octet-truss lattices, gyroids, or inspired architectures like sodalite zeolite, and C60 buckyballs with micrometric and nanometric feature sizes. Alkaline-earth perovskite morphological, structural, and chemical characteristics are studied. The optical properties of such perovskite architectures are investigated using cathodoluminescence and wide-field photoluminescence emission to estimate the lifetime rate and defects in BaZrO3, CaZrO3, and SrZrO3. From a broad perspective, this AM methodology facilitates the production of 3D-structured mixed oxides. These findings are the first steps toward dimensionally refined high-refractive-index ceramics for micro-optics and other terrains like (photo/electro)catalysis.
Single-emitter super-resolved imaging of radiative decay rate enhancement in dielectric gap nanoantennas Córdova-Castro, R. M., B. Van Dam, A. Lauri, S. A. Maier, R. Sapienza, Y. De Wilde, I. Izeddin, and V. Krachmalnicoff Light: Science and Applications 13, no. 1 (2024) Résumé: High refractive index dielectric nanoantennas strongly modify the decay rate via the Purcell effect through the design of radiative channels. Due to their dielectric nature, the field is mainly confined inside the nanostructure and in the gap, which is hard to probe with scanning probe techniques. Here we use single-molecule fluorescence lifetime imaging microscopy (smFLIM) to map the decay rate enhancement in dielectric GaP nanoantenna dimers with a median localization precision of 14 nm. We measure, in the gap of the nanoantenna, decay rates that are almost 30 times larger than on a glass substrate. By comparing experimental results with numerical simulations we show that this large enhancement is essentially radiative, contrary to the case of plasmonic nanoantennas, and therefore has great potential for applications such as quantum optics and biosensing.

Group Members

Permanent Researchers
– Sébastien BIDAULT
– Claude BOCCARA
– Emmanuel FORT
– Ignacio IZEDDIN

Post-doctoral Researchers
– Daria ANDREOLI
– Egidijus AUKSORIUS
– Charles-Edouard LEROUX
– Nemanja MARKESEVIC
– Thu-Mai NGUYEN

PhD Students
– Clement APELIAN
– Vincent BACOT
– Olivier THOUVENIN
– Peng XIAO

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