Bio-functionalized chalcogenide infrared optical glass fibers have been designed for evanescent wave mid-infrared spectroscopy. Surface biotinylation of the fiber tapered sensing zone has been achieved by reactivity of a maleimide function on sulfhydryl moieties of the glassy surface. Biotin-streptavidin interactions were studied by fiber evanescent wave spectroscopy. Kinetic measurement comparisons of functionalized and non-functionalized fiber surfaces for various protein concentrations have demonstrated the efficient bio-selectivity of the functionalized glass fibers. The protein enrichment of the functionalized glassy surface allows for a significant increase of the protein detection limit, greater than two orders of magnitude as compared to reference non-functionalized fibers. A detection of minute quantities at concentrations as low as 10 parts-per-billion is demonstrated. This study shows that bio-functionalized chalcogenide optical fibers allow to combine successfully surface bio-selectivity and infrared absorption fingerprints measurements to get a remarkable sensitivity enhancement of fiber evanescent wave detection methods in the mid infrared spectral range.

Post-processing and functionalization of optical fibers with engineered properties, as well as multifiber assembly, have been the subject of intensive studies over the past few decades, to provide, for instance, unprecedented signal processing and sensing tools for a variety of applications. However, combining distinct optical functions such as nonlinear pulse processing and linear sensing on a single fiber segment has still remained an elusive challenge in the mid-infrared spectral region. Here, we report the development of very short multi-tapered chalcogenide rods to enable the dual function of supercontinuum generation and evanescent wave sensing in the mid-infrared spectral region. On the one hand, we demonstrate the generation of an ultrabroadband light spectrum ranging from 1.9 to 16 µm with significant average power in 5 cm long tapered multimode Te-As-Se rods pumped by a femtosecond mid-infrared pump laser. On the other hand, we show that a second coiled taper can also be shaped after the broadband frequency conversion and serve as an efficient compact sensing head to collect mid-infrared signatures of alcoholic solutions. Our work represents what we believe to be a new step toward the development of compact fiber devices for mid-infrared sensing technologies.

Simultaneously increasing the spectral bandwidth and average output power of mid-infrared supercontinuum sources remains a major challenge for their practical application. We particularly address this issue for the long mid-infrared spectral region through experimental developments of short tapered rods made from selenide glass by means of supercontinuum generation in the femtosecond regime. Our simple post-processing of glass rods unlocks potentially higher-power and coherent fiber-based supercontinuum sources beyond the 10-mu m waveband. By using a 5-cm-long tapered Ge-Se-Te rod pumped at 6 mu m, a supercontinuum spanning from 2 to 15 mu m (3-14 mu m) with an average output power of 93 mW (170 mW) is obtained for 500-kHz (1-MHz) repetition rate. Additional experiments on other glass families (silica and tellurite) covering distinct spectral regions are also reported to develop and support our analyses. We demonstrate that ultra-broadband spectral broadenings over entire glass transmission windows can be achieved in few-cm-long segments of tapered rods by a fine adjustment of input modal excitation. Numerical simulations are used to confirm the main contribution of the fundamental mode in the ultrafast nonlinear dynamics, as well as the possible preservation of coherence features. Our study opens a new route, to our knowledge, towards the power scaling of high-repetition-rate fiber supercontinuum sources over the full molecular fingerprint region.

Coordination polymers (CPs) have gained significant attention as chemical sensors due to their highly tunable porous structures, enabling selective interactions with target analytes. Lanthanide-based coordination polymers (Ln-CPs) have been extensively utilized in optical sensing, owing to their photoluminescent properties. However, these applications typically require deposition on stable substrates with the appropriate chemical and physical characteristics. This study introduces a simple and rapid in situ synthesis and coating process for Ln-CPs on oxide glass bulks and optical fibers. Eu3+-based CPs were successfully coated onto tellurite and phosphate glasses by using polycarboxylic acids as ligands. Although slight deviations from previously reported crystalline structures were observed, luminescent coatings were effectively formed and demonstrated good adhesion to the tellurite glass substrates. These materials exhibited potential selectivity toward carbonyl compounds, showing an enhanced luminescent response at low concentrations. The successful integration of Ln-CPs onto TZN-based optical fibers underscores their potential for real-time remote sensing, offering promising applications in environmental monitoring, industrial safety, and biomedical diagnostics.

Simultaneously increasing the spectral bandwidth and average output power of mid-infrared supercontinuum sources remains a major challenge for their practical application. We address this issue through experimental developments of short tapered rods made from distinct glasses (silica, tellurite and chalcogenide families) for covering distinct spectral regions by means of supercontinuum generation in the femtosecond regime. We demonstrate that ultra-broadband spectral broadenings over the entire glass transmission window can be achieved in few-cm-long segments of tapered rods by a fine adjustment of input modal excitation. As the most significant example, our simple post-processing of glass rods unlocks the high-power regime for fiber-based supercontinuum sources beyond the 10 micron waveband. By using a 5-cm-long tapered Ge-Se-Te rod pumped at 6 micron, a supercontinuum spanning from 2 to 15 micron (3 to 14 micron) with an average output power of 93 mW (170 mW) is obtained for 500-kHz (1-MHz) repetition rate. Spectral coverages from the visible to 5 micron, and from the visible to 2.7 micron, are also reported with tapered rods made of tellurite and silica glasses, respectively. Numerical simulations are used to confirm the main contribution of the fundamental mode in the ultrafast nonlinear dynamics, as well as the possible preservation of coherence features. Our study opens a new route towards the power scaling of high-repetition-rate fiber supercontinuum sources over the full molecular fingerprint region.

Glasses containing rare-earth ions (RE3+) for upconversion (UC) luminescence have been widely explored in several photonic applications. Materials containing Tm3+ present an intense blue emission when excited in the near-infrared range, allowing them to be used as solid-state lasers and other emitter devices. Tm3+ are generally combined with other RE3+ to improve the UC efficiency; however, increasing the number of dopants can be an issue for their solubility in the glass matrix and for fiber drawing. In this work, alkali-aluminum-phosphate glasses, a host matrix with high RE3+ solubility and fiber-drawing ability, were produced containing different amounts of Tm3+, Nd3+, and Yb3+, as well as the respective tridoped optical fibers. Glass samples containing RE3+ were excited at 808 and 980 nm to evaluate the mechanism involved in the luminescence process. In addition, triply doped optical fibers were excited at 788 and 980 nm, and a bright blue luminescence was observed at both wavelengths. Thus, due to the intense UC emission measured on RE3+ triply doped optical fibers with low optical loss, the developed material presents great potential for fiber-based photonic applications.

The development of compact fiber-based light sources emitting over a wide wavelength range in the mid-infrared and their application to the detection of greenhouse gases and volatile organic compounds still remain of critical interest. In the present work, we make use of several dedicated infrared fibers for implementing a mid-infrared optical device pumped by a thulium doped-fiber laser around 1.965 μm that simultaneously enables a first nonlinear stage of frequency conversion and supercontinuum generation and a second linear stage of gas absorption spectroscopy. As a proof-of-principle, we carry out mid-infrared supercontinuum absorption spectroscopy of methane around 7.7 μm by means of a hollow-core fiber-based gas cell combined to a commercial Fourier-transform infrared spectrometer. Our all-fiber configuration operating in the femtosecond regime at megahertz repetition rate allows the detection of methane concentrations as low as 20 ppm.

The presented work is focused on the optical and magneto-optical characterization of TeO2-ZnO-BaO (TZB) tellurite glasses. We investigated the refractive index and extinction coefficient dispersion by spectroscopic ellipsometry from ultraviolet, 0.193 um, up to mid infrared, 25 um spectral region. Studied glasses exhibited large values of linear (n632 = 1.91-2.09) and non-linear refractive index (n2 = 1.20-2.67x10-11 esu), Verdet constant (V632 = 22-33 radT-1m-1) and optical band gap energy (Eg = 3.7-4.1 eV). The materials characterization revealed that BaO substitution by ZnO leads (at constant content of TeO2) to an increase in linear and nonlinear refractive index as well as Verdet constant while the optical band gap energy decreases. Fiber drawing ability of TeO2-ZnO-BaO glassy system has been demonstrated on 60TeO2-20ZnO-20BaO glass with presented mid infrared attenuation coefficient. Specific parameters such as dispersion and single oscillator energy, Abbe number, and first-/ third-order optical susceptibility are enclosed together with the values of magneto-optic anomaly derived from the calculation of measured dispersion of the refractive index.

We report the implementation of an optical bench to measure the electro-optical Kerr constant in bulk infrared glasses, especially for two different infrared glass families: tellurites and chalcogenides. We give a detailed description of the setup, including the specially designed Kerr cell. The samples preparation and the setup validation with a reference material are reported. Finally, we measure the Kerr constant of two compositions that we use as core glasses for the realization of hybrid fibers: 70 TeO2 - 25 ZnO - 05 La2O3 (mol. %) tellurite glass at 633 nm and 20 Ge - 60 Se - 20 Te (mol. %) chalcogenide glass at 3.39 mu m. To our knowledge, this is the first measurement of electro-optical Kerr constant for a chalcogenide glass.

We experimentally demonstrate that simple tapered Ge-Se-Te glass rods with femtosecond pumping enables efficient multi-octave mid-infrared supercontinuum generation, from 1.7 to 16 µm, while keeping an excellent spatial beam profile.

Since the development of the first fibroscope in the late nineteenth century, the use of innovating glass fibers has opened promising perspectives for medical applications particularly in the domain of multimodal imagery [1] . In this work, tellurite glasses have been used to design step-index optical fibers with a rectangular core-section for supercontinuum generation in the near infrared domain. The tellurite glasses selection and the fibers manufacturing by the stack-and-draw process will be presented. Characterizations performed on bulk samples and fibers will also be detailed [2] . The spectral broadening, which is obtained in this work in a short fiber sample, is used for imaging mouse kidney cells, labelled with three different fluorochromes, by means of two and three-photon absorption. Despite the multimode nature of the output beam, clear images of tubules, actin and nucleus are collected with a spatial resolution down to 1.2 µm [3] .

Herein, a tellurite multimode optical fiber with a rectangular step‐index core to combine easy coupling of the pump power with the exceptionally cubic nonlinearity of such type of glass is developed. An alkali‐free composition (TeO 2 –ZnO–La 2 O 3 ) is prepared to produce a preform with the use of both the stack‐and‐draw and the direct‐bonding methods. The linear and nonlinear optical responses of the fiber are characterized and are then used to generate a homogeneous supercontinuum (SC) in the near‐infrared domain. The spectral broadening, which is obtained in this work in a short fiber sample, is used for imaging mouse kidney cells, labeled with three different fluorochromes, by means of two‐photon absorption (2PA) and three‐photon absorption (3PA). Despite the multimode nature of the output beam, clear images of tubules, actin, and nucleus are collected with a spatial resolution down to 1.2 μm. Although image acquisition at better resolution has already been reported in the literature using relatively long spans of graded‐index silica multimode fibers, here, the combination of high third‐order susceptibility of the glass and the large Raman gain in short segments of tellurite fiber is exploited to obtain nonlinear imaging with adequate spatial resolution.

Mid-infrared supercontinuum sources are particularly important for identifying and characterizing molecules and materials through spectroscopy, thus enabling key applications. We here demonstrate the possibility of combining both mid-IR supercontinuum generation and evanescent wave spectroscopy in a single chalcogenide fiber device by means of heat-and-draw processes to manage linear and nonlinear wave-guiding properties.

Among the different fundamental aspects that govern the design and development of elongated multimaterial structures via the preform-to-fiber technique, material association methodologies hold a crucial role. They greatly impact the number, complexity and possible combinations of functions that can be integrated within single fibers, thus defining their applicability. In this work, a co-drawing strategy to produce monofilament microfibers from unique glass-polymer associations is investigated. In particular, the molten core-method (MCM) is applied to several amorphous and semi-crystalline thermoplastics for their integration within larger glass architectures. General conditions in which the MCM can be employed are established. It is demonstrated that the classical glass transition temperature compatibility requirements for glass-polymer associations can be overcome, and that other glass compositions than chalcogenides can be thermally stretched with thermoplastics, here oxide glasses are considered. Composite fibers with various geometries and compositional profiles are then presented to illustrate the versatility of the proposed methodology. Finally, investigations are focused on fibers produced from the association of poly ether ether ketone (PEEK) with tellurite and phosphate glasses. It is demonstrated that upon appropriate elongation conditions, the crystallization kinetics of PEEK can be controlled during the thermal stretching and crystallinities of the polymer as low as 9 mass. % are reached in the final fiber. It is believed such novel material associations as well as the ability to tailor material properties within fibers could inspire the development of a new class of hybrid elongated objects with unprecedented functionalities.

Adaptative objects based on shape-memory materials are expected to significantly impact numerous technological sectors including optics and photonics. In this work, we demonstrate the manufacturing of shape-memory optical fibers from the thermal stretching of additively manufactured preforms. First, we show how standard commercially-available thermoplastics can be used to produce long continuously-structured microfilaments with shape-memory abilities. Shape recovery as well as programmability performances of such elongated objects are assessed. Next, we open the way for light-guiding multicomponent fiber architectures that are able to switch from temporary configurations back to user-defined programmed shapes. We strongly expect that such actuatable fibers with light-guiding abilities will trigger exciting progress of unprecedented smart devices in the areas of photonics, electronics, or robotics.

We numerically and experimentally investigate an all-fiber configuration of coherent mid-infrared supercontinuum generation in the femtosecond pumping regime. In particular, we demonstrate the advantageous combination of various dispersion-engineered chalcogenide (Ge-Se-Te glass) fibers with a turn-key amplified femtosecond fiber laser delivering 175-fs soliton pulses around 3.4 & mu;m and developed from the erbium-doped fluoride fiber technology. Our results show that compact and coherent octave-spanning fiber supercontinuum sources centered on the 2-5 & mu;m infrared atmospheric window can be obtained with a maximum average power of 50 mW at 25 MHz repetition rate.

Among the different fundamental aspects that govern the design and development of elongated multimaterial structures via the preform-to-fiber technique, material association methodologies hold a crucial role. They greatly impact the number, complexity and possible combinations of functions that can be integrated within single fibers, thus defining their applicability. In this work, co-drawing strategies to produce monofilament microfibers from unique glass-polymer associations are discussed.

Mid-Infrared methane (CH 4 ) spectroscopy results were obtained in band III beyond 7 µm. To achieve this, the generation of supercontinuum covering the spectral range between 5 and 12 µm was realized by using purified chalcogenide optical fibers free of highly toxic elements such as arsenic and antimony. Besides a pumping with an optical parametric amplifier, an all fibered pumping scheme has also been investigated. In both configuration, supercontinuum absorption spectroscopy experiments have allowed for CH 4 sensing, concentration as low as 14 ppm has been detected.

We report on the experimental development of short-tapered chalcogenide-glass rods for mid-infrared supercontinuum generation. Multi-octave spectral broadening of femtosecond laser pulses is demonstrated from 1.6 to 15.6 µm in a 5-cm-long tapered Ge20Se70Te10 rod with a waist diameter of 25 µm. Despite the multimode nature of the optical waveguide used, this work clearly shows the potential of such simple post-processed rods for advancing fiber SC sources with infrared glasses, thereby unlocking new possibilities in terms of coupling efficiency, spectral coverage, and output power.

We report a detailed numerical investigation of step-index tellurite fiber properties based on the careful experimental characterization of refractive indices for two tellurite-glass systems employed in fiber manufacturing. More specifically, our study focuses on two typical step-index configurations, namely weak and strong index differences between core and cladding glasses. We reveal that a wide range of dispersion-shifted features for tellurite fibers can be obtained in the 2–3 μm range combined with small or large effective mode areas. Our work also outlines the potential application of such dispersion-engineered fibers for nonlinear wavelength converters between near- and mid-infrared regions.