Birefringent Anti-Resonant Hollow-Core Fiber

Hollow-core fibers have demonstrated record performance in applications such as high-power pulse delivery, quantum computing, and sensing. However, their routine use is yet to become reality. A major obstacle is the ability to maintain the polarization state of light over a broad range of wavelengths, while also ensuring single-mode guidance and attenuation that is low enough for practical applications that require only a few meters of fiber length (&lt;1 dB/m). Here we simulated, fabricated, and characterized a single-mode birefringent anti-resonant hollow-core fiber. The birefringence was achieved by introducing capillary tubes of different thicknesses, thereby creating reduced symmetry in the structure. The measured group birefringence is in good agreement with the calculated group birefringence from simulations across the fiber guidance band within the telecommunications C-band. At 1550 nm, we measured a group birefringence of 4.4 × 10-5, which corresponds to a phase birefringence of 2.5 × 10-5. The measured loss of the fiber was 0.46 dB/m at 1550 nm. The measured polarization extinction ratio of the fiber at 1550 nm was 23.1 dB (25.7 dB) along the x-(y-) polarization axis, relating to an h-parameter of 9.8 × 10-4 (5.3 × 10-4).</p

Design and optimization of multilayer coatings for the generation of colorimetric effects

Les composants à base de couches minces constituent une voie prometteuse pour le contrôle des couleurs. Ceux-ci peuvent être utilisés pour adapter précisément la réflexion ou la transmission d’une surface afin de générer des couleurs à haute saturation et contrôlées avec précision. Ils permettent également de produire des effets uniques tels que l’iridescence angulaire ou des changements de couleur "actif". Un empilement de quatre couches utilisant Ag, SiO2 et Ti est présenté pour le contrôle de la couleur et la génération de couleurs à haute saturation et luminance. Nous avons obtenu la dispersion d’indice de réfraction de couches minces de Ti sur une plage de longueurs d’onde de 370 à 835 nm pour des couches de 6 à 100 nm d’épaisseur.Des revêtements de couleur rouge/vert/bleu et cyan/magenta/jaune ont été conçus à partir de ces matériaux. Nous avons exploré les limites théoriques et expérimentales des revêtements simples à quatre couches (métal/diélectrique/métal/diélectrique) en termes de luminance et de chroma, et avons montré des performances proches ou supérieures aux limites des couleurs de peintures connues. Dans les expériences, les traitements multicouches déposés (fabriqués par dépôt par faisceau d’électrons) ont montré un accord très proche avec les résultats simulés, démontrant une caractérisation précise des couches minces.Les conceptions de traitements utilisant Sb2S3 ont été conçus. Il a été démontré que le Sb2S3 possède des propriétés supérieures pour la conception de revêtements à variation de couleur, et peut être utilisé dans différentes configurations pour créer différents effetsA promising avenue for colour control is via thin film coatings. These can be usedto precisely tailor the reflectance or transmittance of a surface to generate precisely-controlled, high-chroma colours. They could also enable unique effects such asangle-dependent iridescence, or "active" colour-shift coatings exploiting the refractiveindex change of phase-change materials. A four-layer stack using Ag, SiO2 and Ti is demonstrated for colour control andgeneration of high-chroma colours. Characterisation was performed for these threematerials, with particular focus on the semi-transparent Ti layer. We obtained the refractive index ofthin Ti layers over a wavelength range of 370 – 835 nm for layers between 6 nm and100 nm.Red/green/blue and cyan/magenta/yellow colour coatings were designed usingthese materials. We explored the theoretical and experimental limits of simple four-layer (metal/dielectric/metal/dielectric) coatings in terms of brightness and chroma,and obtained performances close to or exceeding the limits of known paint colours. Inexperiments, the deposited coatings (manufactured using electron-beam deposition)showed a very close agreement with the simulated results, demonstrating precisecharacterisation of the thin-film layers.Additionally, the possibility of using active materials with an exploitable indexchange was investigated. Two coating designs using the phase-change material Sb2S3were deposited. It was shown that Sb2S3 has well-suited properties for design ofcolour-shift coatings, and can be used in different configurations to create differenteffects, enabling a large hue shift as the sample is heate

High‐Chroma Color Coatings Based on Ag/SiO2/Ti/SiO2 Structures

International audienceA four-layer metal–dielectric–metal–dielectric (MDMD) stack design for color control is demonstrated. This stack incorporates Ag, SiO2, and Ti as materials, enabling wide absorbance bands, high reflectance peaks, and a strongly tunable color. A wide gamut is obtained by varying the thickness of the SiO2 cavity layer, and the resulting colors exhibit outstanding luminance and chroma. Coatings of red, green, and blue colors are designed and deposited. These coatings demonstrate a very close agreement between the simulated and experimental results. The chroma of the coatings is found to be similar to or exceeded the limits of the Pointer gamut, an empirical gamut of colors in reflectance. This shows that, in the generation of surface color, even for a simple four-layer stack, the performance of thin-film coatings can rival or exceed that of traditional paints and dyes

Precise spectrophotometric method for semitransparent metallic thin-film index determination using interference enhancement

International audienceAbstract A precise spectrophotometric method to determine the refractive index of a semitransparent metallic thin film is presented. This method relies on interference enhancement of the measured spectra, employing an opaque substrate with a dielectric spacer layer beneath the absorbing layer of interest to create interference fringes.The resulting spectral oscillations of the stack are highly sensitive to the properties of the top absorbing layer, allowing precise determination of the refractive index via fitting. The performance of this method is verified using simulations in comparison to the typical method of depositing the absorbing thin film directly onto a transparent substrate. An experimental demonstration is made for titanium thin films over the visible range (370-835 nm). The refractive index of these films is extracted from experimental data using a combination of the Modified Drude and Forouhi-Bloomer models. This method showed high repeatability and precision, and is verified for Ti films between 6-70 nm thickness

Dataset for "Birefringent Anti-resonant Hollow-core Fiber"

This dataset contains data supporting the results presented in the paper "Birefringent Anti-resonant Hollow-core Fiber" and the supplementary material. It includes the data used to plot each figure (in .xlsx format), together with simulated data obtained using COMSOL. Hollow-core fibres have demonstrated record performance in applications such as high-power pulse delivery, quantum computing, and sensing. However, their routine use is yet to become reality. A major obstacle is the ability to maintain the polarisation state of light over a broad range of wavelengths, while also ensuring single-mode guidance and attenuation that is low enough for practical applications that require only a few meters of fibre length (<1 dB/m). Here we simulated, fabricated and characterized a single-mode birefringent anti-resonant hollow-core fibre. The birefringence was achieved by introducing capillary tubes of different thicknesses, thereby creating reduced symmetry in the structure. The measured group birefringence is in good agreement with the calculated group birefringence from simulations across the fibre guidance band within the telecommunications C-band. At 1550 nm, we measured a group birefringence of 4.4E-5, which corresponds to a phase birefringence of 2.5E-5. The measured loss of the fibre was 0.46 dB/m at 1550 nm. The measured polarisation extinction ratio of the fibre at 1550 nm was 23.1 dB (25.7 dB) along the x-(y-) polarisation axis, relating to an h-parameter of 9.8E-4 (5.3E-4).The different data collection methods used for the collection of the data are described in the paper Birefringent Anti-resonant Hollow-core Fiber

Dataset for "Birefringent Anti-resonant Hollow-core Fiber"

This dataset contains data supporting the results presented in the paper "Birefringent Anti-resonant Hollow-core Fiber" and the supplementary material. It includes the data used to plot each figure (in .xlsx format), together with simulated data obtained using COMSOL. Hollow-core fibres have demonstrated record performance in applications such as high-power pulse delivery, quantum computing, and sensing. However, their routine use is yet to become reality. A major obstacle is the ability to maintain the polarisation state of light over a broad range of wavelengths, while also ensuring single-mode guidance and attenuation that is low enough for practical applications that require only a few meters of fibre length (<1 dB/m). Here we simulated, fabricated and characterized a single-mode birefringent anti-resonant hollow-core fibre. The birefringence was achieved by introducing capillary tubes of different thicknesses, thereby creating reduced symmetry in the structure. The measured group birefringence is in good agreement with the calculated group birefringence from simulations across the fibre guidance band within the telecommunications C-band. At 1550 nm, we measured a group birefringence of 4.4E-5, which corresponds to a phase birefringence of 2.5E-5. The measured loss of the fibre was 0.46 dB/m at 1550 nm. The measured polarisation extinction ratio of the fibre at 1550 nm was 23.1 dB (25.7 dB) along the x-(y-) polarisation axis, relating to an h-parameter of 9.8E-4 (5.3E-4)

Dataset for "Birefringent Anti-resonant Hollow-core Fiber"

This dataset contains data supporting the results presented in the paper "Birefringent Anti-resonant Hollow-core Fiber" and the supplementary material. It includes the data used to plot each figure (in .xlsx format), together with simulated data obtained using COMSOL. Hollow-core fibres have demonstrated record performance in applications such as high-power pulse delivery, quantum computing, and sensing. However, their routine use is yet to become reality. A major obstacle is the ability to maintain the polarisation state of light over a broad range of wavelengths, while also ensuring single-mode guidance and attenuation that is low enough for practical applications that require only a few meters of fibre length (<1 dB/m). Here we simulated, fabricated and characterized a single-mode birefringent anti-resonant hollow-core fibre. The birefringence was achieved by introducing capillary tubes of different thicknesses, thereby creating reduced symmetry in the structure. The measured group birefringence is in good agreement with the calculated group birefringence from simulations across the fibre guidance band within the telecommunications C-band. At 1550 nm, we measured a group birefringence of 4.4E-5, which corresponds to a phase birefringence of 2.5E-5. The measured loss of the fibre was 0.46 dB/m at 1550 nm. The measured polarisation extinction ratio of the fibre at 1550 nm was 23.1 dB (25.7 dB) along the x-(y-) polarisation axis, relating to an h-parameter of 9.8E-4 (5.3E-4)