Femtosecond laser-induced integrated photonic architectures for infrared fluorescent microscopy standards – ArchiFLUO

There is a strong need nowadays by confocal microscope end-users and manufacturers to access reliable and quantitative imaging in the extended red/infrared spectral range, as crucially demanded by the pharmaceutical industry (red fluorescence), for biology imaging needs of living tissues (near-IR at 0.9-1 µm) or for molecular sensing (mid-IR in the finger print spectral range). This means that there is an identified lack of industrial solutions in terms of optical standards to calibrate such microscopes in the red/infrared range. Therefore, there is a clear necessity to produce new integrated photonics solutions for optical standards based on high-contrast red/IR emitting structures distributed in 3D with sub-wavelength resolution. Concomitantly, 3D photonic architectures with rationally-engineered sub-wavelength periodicities have led this last decade to breakthrough concepts in photonics as well as in major achievements such as three-dimensional linear/nonlinear photonic crystals and metamaterials in optics. Despite remarkable achievements, it is still highly challenging to address such direct 3D fabrication by versatile all-optical laser-based means (not lithography, no clean room), in perennial materials (not polymers), with fully embedded architectures in a robust medium as glasses (not printing on a substrate, as in 3D printing) with technological transfer compatibility.

In this context, the project ArchiFLUO ambitions firstly to develop innovative highly-photosensitive glasses under laser irradiation, to understand and improve fundamental mechanisms of glass modifications so as to create high-contrast red/IR emitting structures with sub-wavelength resolution. This will be investigated either by playing on the glass matrix behavior by introducing co-mobile alkali ions, by achieving resonant energy transfers from localized fluorescent silver clusters to IR emitters (rare earth or transition metal ions) or by the local precipitation of fluorescent dielectric / semiconductor nanocrystallites in fluoride / heavy metal oxide glasses. Secondly, ArchiFLUO ambitions to develop challenging all-optical laser-based approaches in inorganic glasses, to directly create multi-scale linear and/or nonlinear photonic crystal architectures for integrated applications such as light management or optical sensing. Thirdly, ArchiFLUO aims to succeed in technological transfer in glass science and laser irradiation processes to allow for the demonstration of new optical standard prototype as well as for the potential emergence of new industrial products so as to fill the gap of highly-demanded but still missing reliable optical standards with extended spectral range for fluorescence imaging calibration.

ArchiFLUO is a collaborative multi-disciplinary PRCE ANR project with four partners with international visibility and recognized expertise in glass science, in material and mechanism characterization, and in femtosecond laser modification of materials, namely ICMCB, CELIA, LSI and the company ARGOLIGHT. ArchiFLUO targets thus to develop cutting-edge research in both glass elaboration and in laser manufacturing, compatible with international-grade progress, which will allow for an enlarged international scientific visibility to the partners as well as an international leadership in the targeted scientific topics. ArchiFLUO will also strengthen the pioneer position of ARGOLIGHT as an innovative optical standard manufacturer.