Publications

2023

• Polarized Light in Biomedical Imaging and Sensing
  
  • Ramella-Roman Jessica
  • Novikova Tatiana
  , 2023. (10.1007/978-3-031-04741-1)
  DOI : 10.1007/978-3-031-04741-1
• Bimodal ionic photomemristor based on a high-temperature oxide superconductor/semiconductor junction
  
  • El Hage Ralph
  • Humbert Vincent
  • Rouco Victor
  • Sánchez-Santolino Gabriel
  • Lagarrigue Aurelien
  • Seurre Kevin
  • Carreira Santiago
  • Sander Anke
  • Charliac Jérôme
  • Mesoraca Salvatore
  • Trastoy Juan
  • Briatico Javier
  • Santamaría Jacobo
  • Villegas Javier
  Nature Communications, Nature Publishing Group, 2023, 14 (1), pp.3010. Abstract Memristors, a cornerstone for neuromorphic electronics, respond to the history of electrical stimuli by varying their electrical resistance across a continuum of states. Much effort has been recently devoted to developing an analogous response to optical excitation. Here we realize a novel tunnelling photo-memristor whose behaviour is bimodal: its resistance is determined by the dual electrical-optical history. This is obtained in a device of ultimate simplicity: an interface between a high-temperature superconductor and a transparent semiconductor. The exploited mechanism is a reversible nanoscale redox reaction between both materials, whose oxygen content determines the electron tunnelling rate across their interface. The redox reaction is optically driven via an interplay between electrochemistry, photovoltaic effects and photo-assisted ion migration. Besides their fundamental interest, the unveiled electro-optic memory effects have considerable technological potential. Especially in combination with high-temperature superconductivity which, in addition to facilitating low-dissipation connectivity, brings photo-memristive effects to the realm of superconducting electronics. (10.1038/s41467-023-38608-0)
  DOI : 10.1038/s41467-023-38608-0
• Gold metallization of hybrid organic-inorganic polymer microstructures 3D printed by two-photon polymerization
  
  • Bretosh Kateryna
  • Hallais Simon
  • Chevalier-Cesar Clotaire
  • Zucchi Gaël
  • Bodelot Laurence
  Surfaces and Interfaces, Elsevier, 2023, 39, pp.102895. Two-photon polymerization is a femtosecond laser-based technique enabling printing of three-dimensional structures down to submicron resolution within photocurable polymers. Rendering the dielectric 3D printed structures conductive can be of great benefit for various applications in domains such as energy, photonics, or multifunctional devices. In this work, the microstructures of interest are made of a silicon-zirconium hybrid organic-inorganic polymer exhibiting low shrinkage during development. A simple and efficient metallization method by electroless plating is investigated to deposit a gold layer on the surface of the printed microstructures. The influence of the method parameters on the quality and properties of the deposited layer is studied. Among these parameters, the surface modification agent concentration and step duration, as well as the seeding solution concentration, must be adapted to the specific case of the considered hybrid microstructures. The concentration of metal ions in the plating bath is the most influential parameter on the morphology of the deposited gold layers. In particular, higher concentrations lead to smooth and continuous layers with electrical conductivities higher than half that of bulk gold. Finally, the deposited layers are shown to coat 3D printed microstructures of arbitrary shapes, thus confirming the conformality of the method at the micrometric scale. (10.1016/j.surfin.2023.102895)
  DOI : 10.1016/j.surfin.2023.102895
• Effects of formalin fixation on polarimetric properties of brain tissue: fresh or fixed?
  
  • Gros Éléa
  • Rodríguez-Núñez Omar
  • Felger Leonard
  • Moriconi Stefano
  • Mckinley Richard
  • Pierangelo Angelo
  • Novikova Tatiana
  • Vassella Erik
  • Schucht Philippe
  • Hewer Ekkehard
  • Maragkou Theoni
  Neurophotonics, Society of Photo-optical Instrumentation Engineers (SPIE), 2023, 10 (02), pp.025009. Significance: Imaging Mueller polarimetry (IMP) appears as a promising technique for real-time delineation of healthy and neoplastic tissue during neurosurgery. The training of machine learning algorithms used for the image post-processing requires large data sets typically derived from the measurements of formalin-fixed brain sections. However, the success of the transfer of such algorithms from fixed to fresh brain tissue depends on the degree of alterations of polarimetric properties induced by formalin fixation (FF). Aim: Comprehensive studies were performed on the FF induced changes in fresh pig brain tissue polarimetric properties. Approach: Polarimetric properties of pig brain were assessed in 30 coronal thick sections before and after FF using a wide-field IMP system. The width of the uncertainty region between gray and white matter was also estimated. Results: The depolarization increased by 5% in gray matter and remained constant in white matter following FF, whereas the linear retardance decreased by 27% in gray matter and by 28% in white matter after FF. The visual contrast between gray and white matter and fiber tracking remained preserved after FF. Tissue shrinkage induced by FF did not have a significant effect on the uncertainty region width. Conclusions: Similar polarimetric properties were observed in both fresh and fixed brain tissues, indicating a high potential for transfer learning. (10.1117/1.NPh.10.2.025009)
  DOI : 10.1117/1.NPh.10.2.025009
• Femtosecond laser direct writing multilayer chiral waveplates with minimal linear birefringence
  
  • Lu Jiafeng
  • Garcia-Caurel Enrique
  • Ossikovski Razvigor
  • Courvoisier François
  • Zeng Xianglong
  • Poumellec Bertrand
  • Lancry Matthieu
  Optics Letters, Optical Society of America - OSA Publishing, 2023, 48 (2), pp.271-274. Chirality transfer from femtosecond laser direct writing in achiral transparent materials mainly originates from the interplay between anisotropic nanogratings and mechanical stress with non-parallel and non-perpendicular (oblique) neutral axes. Yet, the laser fabrication simultaneously induces non-negligible linear birefringence. For precise manipulation of circular polarization properties, as well as to unlock the full functionality, we report here a geometryinspired multilayer method for direct writing of chiral waveplates with minimal linear birefringence. We perform a theoretical analysis of both circular and linear properties response for different multilayer configurations and achieve strong circular birefringence of up to −2.25 rad with an extinction ratio of circular birefringence to total linear birefringence of up to 5.5 dB at 550 nm. Our strategy enables the precise control of circular properties and provides a facile platform for chiral device exploration with almost no linear property existence. (10.1364/OL.479447)
  DOI : 10.1364/OL.479447
• Styrylpyrimidine chromophores with bulky electron-donating substituents: experimental and theoretical investigation
  
  • Hodée Maxime
  • Massue Julien
  • Achelle Sylvain
  • Fihey Arnaud
  • Tondelier Denis
  • Ulrich Gilles
  • Le Guen Françoise Robin
  • Katan Claudine
  Physical Chemistry Chemical Physics, Royal Society of Chemistry, 2023, 25, pp.32699. Styrylpyrimidine with bulky 9,9-dimethylacridan, phenoxazine and phenothiazine electron-donating fragment were designed. Thermally activated delayed fluorescence (TADF) properties were expected for these structures. These chromophores exhibit peculiar emission properties. For 9,9-dimethylacridan and phenoxazine derivatives, a single emission highly sensitive to the polarity is observed in solution whereas for phenothiazine derivative a dual emission is observed in solution and is attributed to the coexistence of quasi-axial (Qax) and quasi-equatorial (Qeq) conformers. This study intends to understand with theoretical and experimental works, why the studied chromophores do not exhibit TADF properties, contrary to what was expected. The absence of phosphorescence both at room temperature and 77K tends to indicate the impossibility to harvest triplet states in these systems. Wave-function based calculations show that for both conformers of the three chromophores the S1-T1 splitting is significantly larger than 0.2 eV. The second triplet state T2 of Qeq conformers is found very close in energy to the singlet S1 state, but S1 and T2 states possess similar charge transfer characters. This prevents efficient spin-orbit coupling between the states, which is consistent with the absence of TADF. (10.1039/D3CP03705C)
  DOI : 10.1039/D3CP03705C
• Motion-Constrained GNSS/INS Integrated Navigation Method Based on BP Neural Network
  
  • Xu Ying
  • Wang Kun
  • Jiang Changhui
  • Li Zeyu
  • Yang Cheng
  • Liu Dun
  • Zhang Haiping
  Remote Sensing, MDPI, 2023, 15 (1), pp.154. The global navigation satellite system (GNSS) and inertial navigation system (INS) integrated navigation system have been widely used in Intelligent Transportation Systems (ITSs). However, the positioning error of integrated navigation systems is rapidly divergent when GNSS outages occur. Motion constraint and back propagation (BP) neural networks can provide additional knowledge to solve this issue. However, the predictions of a neural network have outliers and motion constraint is difficult to adapt according to the motion states of vehicles and boats. Therefore, this paper fused a BP neural network with motion constraints, and proposed a motion-constrained GNSS/INS integrated navigation method based on a BP neural network (MC-BP method). The pseudo-measurement of the GNSS was predicted using a fitting model trained by the BP neural network. At the same time, the prediction outliers were detected and corrected using motion constraint. To assess the performance of the proposed method, simulated and real data experiments were conducted with a vehicle on land and a boat offshore. A classical GNSS/INS integration algorithm, a motion-constrained GNSS/INS algorithm, and the proposed method were compared through data processing. Compared with the classical GNSS/INS integration algorithm and the motion-constrained GNSS/INS algorithm, the positioning accuracies of the proposed method were improved by 90% and 64%, respectively, in the vehicle land experiment. Similar performances were found in the offshore boat experiment. Using the proposed MC-BP method, improved meter-level-positioning results can be achieved with the GNSS/INS integration algorithm when GNSS outages occur. (10.3390/rs15010154)
  DOI : 10.3390/rs15010154