Gold nanoparticles as contrast agents for nonlinear microscopy

Ph.DDOCTOR OF PHILOSOPH

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Polarized Nonlinear Nanoscopy in Metal and Ferroelectric Nano-Structures

International audienc

Electro-optical polarization modulation in coherent Raman scattering for the observation of molecular dynamics in real-time

International audienc

Effects of Excitonic Resonance on Second and Third Order Nonlinear Scattering from Few-Layer MoS 2

International audienc

Local organization of lipids in myelinated axons probed by polarization resolved coherent anti-stokes Raman scattering nonlinear microscopy

International audienc

Pump probe microscopy of human hair

International audienc

Focusing large spectral bandwidths through scattering media

International audienceWavefront shaping is a powerful method to refocus light through a scattering medium. Its application to large spectral bandwidths or multiple wavelengths refocusing for nonlinear bio-imaging in-depth is however limited by spectral decorrelations. In this work, we demonstrate ways to access a large spectral memory of a refocus in thin scattering media and thick forward-scattering biological tissues. First, we show that the accessible spectral bandwidth through a scattering medium involves an axial spatio-spectral coupling, which can be minimized when working in a confocal geometry. Second, we show that this bandwidth can be further enlarged when working in a broadband excitation regime. These results open important prospects for multispectral nonlinear imaging through scattering media

Polarized nonlinear nanoscopy of metal nanostructures

International audienc

Polarized nonlinear nanoscopy of metal nanostructures

International audienceNonlinear signals from metal nanostructures are known to be highly polarization-dependent, due to the intrinsic vectorial nature of nonlinear optical coupling. Nonlinear optical polarization responses contain important information on the near-field properties of nanostructures; however they remain complex to monitor and to model at the nano-scale. Polarization resolved nonlinear optical microscopy can potentially address this question, however the recorded signals are generally averaged over the diffraction-limited size of a few hundreds of nanometers, thus missing the spatial specificity of the nanostructure's optical response. Here we present a method of polarized nanoscopy that exploits sub-diffraction resolution information down to a few tens of nanometer. Even though the resulting image is diffraction-limited, the information gained by polarization-induced modulation provides a higher level of selectivity that is directly related to vectorial optical responses at a scale below the diffraction limit. We show that polarized nonlinear nanoscopy permits to spatially map the vectorial nature of plasmonic nonlinear optical interactions in nanostructures