A5026263629- Laser-Matter Interactions and Applications
- Nonlinear Optical Materials Studies
- Advanced Fiber Laser Technologies
- Spectroscopy Techniques in Biomedical and Chemical Research
- Advanced Fluorescence Microscopy Techniques
- Spectroscopy and Quantum Chemical Studies
- Nanoplatforms for cancer theranostics
- Photoacoustic and Ultrasonic Imaging
- Gold and Silver Nanoparticles Synthesis and Applications
- Photoreceptor and optogenetics research
- Laser Material Processing Techniques
- Photodynamic Therapy Research Studies
- Advanced Chemical Physics Studies
- Ocular and Laser Science Research
- Nanoparticle-Based Drug Delivery
- Advanced Biosensing Techniques and Applications
- Nonlinear Optical Materials Research
- 3D Printing in Biomedical Research
- Photonic and Optical Devices
- Protein Interaction Studies and Fluorescence Analysis
- Terahertz technology and applications
- Plasmonic and Surface Plasmon Research
- Quantum Dots Synthesis And Properties
- Luminescence and Fluorescent Materials
- Laser-Plasma Interactions and Diagnostics
University of Geneva
2015-2024
Leibniz Institute for High Performance Microelectronics
2024
European Organization for Nuclear Research
2024
École Polytechnique Fédérale de Lausanne
2004-2018
University of Basel
2017-2018
University of Zurich
2017-2018
HES-SO Genève
2014-2018
Institute of Applied Physics
2018
Charles Humbert 8
2017
Laboratoire de Mécanique des Sols, Structures et Matériaux
2010
Nonlinear optical nanocrystals have been recently introduced as a promising alternative to fluorescent probes for multiphoton microscopy. We present the first time complete survey of properties five nanomaterials (KNbO(3), LiNbO(3), BaTiO(3), KTP, and ZnO), describing their preparation stabilization providing quantitative estimations nonlinear response. In light prospective use biological clinical markers, we assess biocompatibility on human healthy cancerous cell lines. Finally, demonstrate...
Though it has been shown that immunological functions of CD4+ T cells are time day-dependent, the underlying molecular mechanisms remain largely obscure. To address question whether themselves harbor a functional clock driving circadian rhythms immune function, we analyzed gene expression by qPCR in unstimulated and responses PMA/ionomycin stimulated FACS analysis purified from blood healthy subjects at different points throughout day. Molecular as well function was further which were...
The mammalian circadian timing system consists of a master pacemaker in the suprachiasmatic nucleus (SCN) hypothalamus, which is thought to set phase slave oscillators virtually all body cells. However, due lack appropriate vivo recording technologies, it has been difficult study how SCN synchronizes peripheral tissues. Here we describe real-time bioluminescence emitted by hepatocytes expressing luciferase reporter genes freely moving mice. technology employs device dubbed RT-Biolumicorder,...
We report the generation of 30 microJ single-cycle terahertz pulses at 100 Hz repetition rate by phase-matched optical rectification in lithium niobate using 28 mJ femtosecond laser pulses. The phase-matching condition is achieved tilting pulse intensity front. Temporal, spectral, and propagation properties generated are presented. In addition, we discuss possibilities for further increasing energy obtained rectification.
Nonlinear photon conversion is a fundamental physical process that lies on the basis of many modern disciplines, from bioimaging and theranostics in nanomedicine to material characterization materials science nanotechnology. It also holds great promise laser physics with applications information technology for optical signal processing development novel coherent light sources. The capability efficiently generate harmonics at nanoscale will have an enormous impact all these fields, since it...
It has been assumed that the suprachiasmatic nucleus (SCN) synchronizes peripheral circadian oscillators. However, this never convincingly shown, since biochemical time series experiments are not feasible in behaviorally arrhythmic animals. By using long-term bioluminescence recording freely moving mice, we show SCN is indeed required for maintaining synchrony between organs. Surprisingly, however, oscillations persist livers of mice devoid an or oscillators cells other than hepatocytes....
Nonlinear spectroscopy and microscopy techniques are ubiquitous in a wide range of applications across physics biology. However, these usually rely on high-powered pulsed laser systems. A promising alternative is to exploit entangled two-photon absorption (ETPA), which can lead tens orders magnitude lower incident flux rates than conventional (TPA) schemes. the role different degrees freedom ETPA was unclear following recent experimental studies, when compared earlier theoretical works....
Harmonic Nanoparticles are a new family of exogenous markers for multiphoton imaging exerting optical contrast by second harmonic (SH) generation. In this tutorial, we present the application Hyper-Rayleigh Scattering (HRS) quantitative assessment nonlinear properties these particles and discuss underlying theory some crucial experimental aspects. The BaTiO3, KNbO3, KiTiOPO4 (KTP), LiNbO3 ZnO nanocrystals (NCs) investigated HRS measurements after careful preparation characterization...
Abstract Bent N,N′‐diphenyl‐dihydrodibenzo[a,c]phenazine amphiphiles are introduced as mechanosensitive membrane probes that operate by an unprecedented mechanism, namely, unbending in the excited state opposed to previously reported untwisting ground and twisting state. Their dual emission from bent or “closed” planarized “open” states is shown discriminate between micelles water monomers solid‐ordered (S o ), liquid‐disordered (L d ) bulk membranes. The dual‐emission spectra cover enough...
We experimentally study entangled two-photon absorption in rhodamine 6G as a function of the spatial properties high flux broadband photon pairs. first demonstrate key signature dependence rate on type pair attenuation: linear, when laser pump power is attenuated, and quadratic, itself experiences linear loss. then perform fluorescence-based Z-scan measurement to influence beam waist size process compare this classical single- processes. that shares similar absorption. This result presents...
We measured the ultrafast response of triangular silver nanoparticles upon femtosecond excitation their plasmon resonance. After a fast electron relaxation, signature bimodal mechanical vibration particle is apparent as spectral modulation. identify two lowest frequency, totally symmetric vibrations responsible for this modulation, through influence on peak position and width, in full agreement with results variational elastodynamic model that also presented. From analysis phase we conclude...
We demonstrate the possibility to excite second-harmonic (SH) active Fe(IO(3))(3) nanocrystals with two distinct laser sources at 800 and 1550 nm, we show, by a complementary experimental numerical study, how wavelength flexibility inherent non-phase-matched SH nanoparticles can be efficiently exploited increase imaging penetration depth of markers embedded in biological samples.
We present a novel optical aerosol particle detector based on Xe flash lamp excitation and spectrally resolved fluorescence acquisition. demonstrate its performances three natural pollens acquiring in real-time scattering intensity at two wavelengths, sub-microsecond time-resolved traces of the particles’ passage focus, UV-excited spectra. show that device gives access to rather specific detection bioaerosol particles.
In order to assess the therapeutic potential of cell-based strategies, it is paramount importance elaborate and validate tools for monitoring behavior injected cells in terms tissue dissemination engraftment properties. Here, we apply bismuth ferrite harmonic nanoparticles (BFO HNPs) vitro expanded human skeletal muscle-derived stem (hMuStem cells), an attractive avenue patients suffering from Duchenne muscular dystrophy (DMD). We demonstrate possibility cell labeling with HNPs. also show...
Hyper Rayleigh scattering (HRS) and second harmonic (SH) microscopy were used to study the order nonlinear optical response of ZnO BaTiO3 nanocrystals, which have been recently proposed as new markers for bioimaging. HRS, combined with dynamic light scattering, was first retrieve hyperpolarizabilities coefficients both type nanocrystals. The results indicate that main contribution SH signal is related bulk noncentrosymmetric structure particles. Successively, we carried out inspection...
The combination of nonlinear optics and nanotechnology is an extremely rich scientific domain yet widely unexplored. We present here a review recent optical investigations on noncentrosymmetric oxide nanoparticles with large response, often referred to as harmonic (HNPs). HNPs feature series properties which distinguish them from other photonics nanoprobes (quantum dots, up-conversion nanoparticles, noble metal particles). emission inherently based the efficient generation harmonics opposed...
We present a novel concept for optical spectroscopy called nonlinear correlation (NLCS). NLCS analyses coherent field fluctuations of the second and third harmonic light generated by diffusing nanoparticles. Particles based on noncentrosymmetric materials such as KNbO(3) show strong well response. The method theory are introduced experimental results in fetal calf serum presented showing promising selectivity this technique measurement complex biological environments.
Femtosecond laser induced multi-photon excited fluorescence (MPEF) from individual airborne particles is tested for the first time discriminating bioaerosols.The spectra, analysed in 32 channels, exhibit a composite character originating simultaneous two-photon and three-photon excitation at 790 nm.Simulants of bacteria aggregates (clusters dyed polystyrene microspheres) different pollen (Ragweed, Pecan, Mulberry) are clearly discriminated by their MPEF spectra.This demonstration experiment...
We investigate the use of bismuth ferrite (BFO) nanoparticles for tumor tissue labeling in combination with infrared multiphoton excitation at 1250 nm. report efficient and simultaneous generation second- third-harmonic signals by nanoparticles. On this basis, we set up a novel imaging protocol based on co-localization two harmonic demonstrate its benefits terms increased selectivity against endogenous background sources samples. Finally, discuss BFO as mapping reference structures...
Second Harmonic Generation (SHG) from BiFeO3 nanocrystals is investigated for the first time to determine their potential as biomarkers multiphoton imaging. Nanocrystals are produced by an auto-combustion method with 2-amino-2-hydroxymethyl-propane-1,3-diol a fuel. Stable colloidal suspensions mean particle diameters in range 100–120 nm then obtained after wet-milling and sonication steps. SHG properties determined using two complementary experimental techniques, Hyper Rayleigh Scattering...