Bruno Bêche - Academia.edu (original) (raw)

Papers by Bruno Bêche

Research paper thumbnail of On the detection of nanoparticle cloud migration by a resonant photonic surface signal towards sedimentation velocity measurements

Results in Optics

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Research paper thumbnail of Determination of Stokes velocities and sedimentation rate by a photonic resonant surface signal

Optical Sensors 2021

The sedimentation of solid particles in a liquid is a physical phenomenon that necessitate to be ... more The sedimentation of solid particles in a liquid is a physical phenomenon that necessitate to be well understood and measured in several cases. In medical diagnosis, a knowledge of the sedimentation speed of red blood cells for example, allows the early diagnosis of various inflammations. In study, optical Micro-Resonators (MRs) are used as sensors to track the dynamical phenomenon of sedimentation of a cloud of nano-particles in water, and the associated consequences on the spectral characteristics of the guided mode are analyzed. A MR is characterized by its eigenvalue, namely the effective index of an optical mode propagating inside. A progressive modification of the environment thus induces a temporal variation of the effective index. Such a variation can be measured by the tracking of the Free Spectral Range (FSR) of the transduced spectra against time. The transduced optical signal is then directed towards an Optical Spectrum Analyzer (OSA) from which spectra are acquired against time. A millimeter tank filled with water is judiciously deposited on the surface of the chip, before the adding of the solution of nano-particles. The spectra are acquired during the whole duration of the process of sedimentation. The data collected this way are then compared to a simple theoretical model describing the sedimentation of a spherical particle in water. Moreover, the sedimentation theory and the derivation of the speed of sedimentation of a spherical particle is presented, plus the presentation of the experimental setup, from the fabrication of the photonic structure by photolithography, to the inclusion of this circuit in an optical characterization platform and the presentation of the data acquisition and treatment program. The experimental results are analyzed and discussed. The differences are around 10% over the theoretical Stokes velocities relating to such sedimentation process. An overall generic curve or spectral response is clearly demonstrated on these sedimentation processes.

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Research paper thumbnail of About monitoring the dynamics of phase transition in food and biology by micro-photonics: detecting soft-matter process

Integrated Photonics Platforms: Fundamental Research, Manufacturing and Applications, 2020

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Research paper thumbnail of About the Heisenberg's uncertainty principle and the determination of effective optical indices in integrated photonics at high sub-wavelength regime

Optik - International Journal for Light and Electron Optics, 2016

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Research paper thumbnail of Marcatili’s extended approach: comparison to semi-vectorial methods applied to pedestal waveguide design

Journal of Optics A: Pure and Applied Optics, 2008

This paper deals with a theoretical study of pedestal waveguides. An extension of the Marcatili m... more This paper deals with a theoretical study of pedestal waveguides. An extension of the Marcatili method has been developed in order to adapt this analytical method to pedestal structures. Simulations are performed for two different T-pedestal waveguide (T-PW) configurations corresponding respectively to a high and a lower core to pedestal widths ratio (T-PW I and T-PW II). Each configuration is

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Research paper thumbnail of Native spider silk as a biological optical fiber

Applied Physics Letters, 2013

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Research paper thumbnail of Versatile Analytic Approach to Assessing Harmonic Distortion in Current Driven Electrodynamic Loudspeakers

Current-controlling loudspeakers has been investigated since a significant time and is known as q... more Current-controlling loudspeakers has been investigated since a significant time and is known as quite appreciated by demanding audiophiles. Today’s new market research clearly moves to investigate on adequate innovative designs together with simple theoretical solutions to deal with their residual non-linear properties. Hence, this paper aims to present a compact analytical approach allowing to synthesize the harmonic distortion hindering the audio quality of electrodynamic loudspeakers, while considering separately the influence of the changes of their main constitutive parameters. As a great convenience the relevant compact way to shape Taylor polynomials provides simple expressions describing the first five harmonic distortion lines on the whole spectrum: Proceeding so clearly highlights the critical influence of each given parameter. Besides consistency when compared with numerical analysis operated with the Simulink ® software, this approach may be easily implemented with a sta...

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Research paper thumbnail of Determination of a statistical lack of volume matter by resonance principle: experiential approach and modeling

In integrated photonics, the calculation of the solutions regarding the propagation equations mod... more In integrated photonics, the calculation of the solutions regarding the propagation equations modes may be summed up as a problem with eigenvalues and eigenvectors to be solved. Based on such global principle, we have investigated the ability to monitor the impact of a lack of material (or void) on the evolution of eigenvalues of waveguides. To this end, specific families of resonators have been designed with several slits nano-inscribed upon them. The signal resonant light is then characterized while considering the whole geometry taking account of the void: thus, it contains the information regarding the pre-defined recessed volume. The UV 210 polymer is processed (deep UV 248 nm) so as to shape specific slots within a set of waveguides. Then, such waveguides have been re-looped as micro-resonators circuits with a view to measuring experimentally relevant variations of the eigenvalue considering the Free Spectral Range (FSR) associated with resonances. Experiments allowed us to hi...

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Research paper thumbnail of Advantages of UV210 polymer for integrated optics applications: comparison of ridge and photoinscripted strip waveguide performances

Journal of Optics, 2015

We report on the propagation performance comparison of two waveguide structures obtained from the... more We report on the propagation performance comparison of two waveguide structures obtained from the same UV210 photoresist. Ridge waveguide structures were fabricated by deep ultraviolet photolithography, and photoinscripted strip waveguides were realized by the same process, excluding the last development step. Structural and optical studies were carried out for both waveguide families, highlighting a well-controlled photolithography process. Predictions of the propagating modes were also led using the beam propagation method, showing a good agreement with experiments in single-mode propagation. Propagation losses were evaluated at 635 nm by cut-back measurement, showing mean loss values that are slightly lower for photoinscripted waveguides than for ridge waveguides. UV210 photoinscripted waveguides thus combine a fast and low-cost process, reduced optical losses, and a planar surface with as many advantages for more complex integrated components.

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Research paper thumbnail of Pristine spider silk fibers as waveguiding microstructure in free space and in an integrated photonic chip

2013 Conference on Lasers & Electro-Optics Europe & International Quantum Electronics Conference CLEO EUROPE/IQEC, 2013

ABSTRACT form only given. Silk fibers produced by nature are among the most interesting materials... more ABSTRACT form only given. Silk fibers produced by nature are among the most interesting materials. Besides their high degree of biocompatibility, they are bioresorbable, ecologically friendly, and offer excellent mechanical properties. In particular, silks of spider and worm have aroused a huge interest as seen by the large literature on their structural organization [1, 2]. Thanks to material engineering possibility [3, 4], regenerated worm silk has been intensively studied and used in different fields such as electronics and photonics [5, 6]. On the other hand, native silks fibers are utilized in textile applications and in surgery procedures but have not yet deserved attention for photonic applications. However, the exceptional mechanical properties of natural silk mainly originate from an elaborated hierarchical organization which has not yet been reproduced in regenerated silk.We demonstrate the promising optical fiber behavior of pristine dragline silk from the spider Nephila clavipes, as well as its integration in a photonic chip made of synthetic polymer microstructures patterned by UV-lithography. The spinning process of the native fiber leads to a diameter of 5 microns, homogeneous over long distances. Since silk manipulation is straightforward, optical propagation in straight and loop configurations has been validated. In free space, attenuation coefficient (propagation losses) and coupling losses were estimated by the cut-back method on straight fiber at 10.5 dB/cm and 10 dB, respectively.In addition, the integration of the pristine silk fiber on a photonic chip and working optical hybrid devices based on synthetic polymer and natural silk fibers were demonstrated. Fig. 1a) is a scanning electron microscope of a chip composed of native spider silk embedded in SU8 microstructures (disk-reservoirs MD1 and MD2) designed by UV-lithography7. During light injection in a SU8 waveguide connected to MD1, light propagates to MD1 where light is confined at the edge- of the disk. Fig. 1b is a micro-beam profile of the chip during light injection and shows that light is confined along the silk fiber and at the edges of MD2. This confirms the optical coupling between synthetic polymer microstructures and silk fiber. These results highlight the potential role of this unique material for biophotonic applications either in free space or in integrated chip for which light propagation and/or sensing in biocompatible media is needed.

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Research paper thumbnail of <title>New practical approach of integrated photonic based on biomimetic peptidic/silica self-assembled nanotubes</title>

Integrated Optics: Devices, Materials, and Technologies XIII, 2009

We report on the first developments for a new approach of integrated photonic using optical evane... more We report on the first developments for a new approach of integrated photonic using optical evanescent coupling from organic microstructures to bundles of hybrid nanotubes (NT). Microstructures are organic disks acting as photon reservoirs, integrated on a photonic chip fabricated by micro-technologic processes. Biomimetic peptidic/ silica nanotubes are realized by molecular self-assembly allowing high aspect ratio. Such heterostructures have been included directly on the organic chip as an innovative solution based on nanotubes in situ chipapproach. The latter allowed us to obtain an adequate evanescent coupling localized between micronic-disks and bundles of nanotubes. As a result, we highlight a specific photonic propagation along various heterostructured- NT-bundles featuring distances beyond the centimeter and losses from 1.2 to 6.6 dB/cm. It presents an advantageous confinement of the optical mode marked with strong energy localizations between nanotubes.

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Research paper thumbnail of First developments for photonics integrated on plasma-polymer-HMDSO: Single-mode TE00–TM00 straight waveguides

Optical Materials, 2007

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Research paper thumbnail of Un échafaudage de peptides pour fabriquer des nanotubes de silice: Une organisation très hiérarchique

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Research paper thumbnail of Hybrid composed method associating conformal transformation with matrix formulation for computing eigenvalues and eigenvectors in bended optical waveguides

Optik - International Journal for Light and Electron Optics, 2017

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Research paper thumbnail of Analysis of giant waveguide tapers with funnel geometry: multi-mode Interference regime to single mode

In this study, we are interested in giant tapers operating in a totally Multi-Mode Interference (... more In this study, we are interested in giant tapers operating in a totally Multi-Mode Interference (MMI) regime capable of producing still an adequate single-mode field at the output. The idea is therefore to provide an answer on a possible giant acceptable limit of such MMI tapers still causing a single-mode output and then determining which opto-geometric parameters on this simple mathematical object and geometry act on the behavior. To this end, we have defined energy criteria per volume at the output. We consider families of tapers with a constant height corresponding to the output rib waveguide and a triangle shape. Each taper is defined by its input size, its length and its output size. The objective is to determine the minimum length of the taper to get enough energy or the desired guided mode(s) in the output waveguide. Two various approaches have been investigated and compared: numerical simulations by a finite element method (COMSOL) and a pure mathematical and geometrical st...

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Research paper thumbnail of Microphotonics for monitoring the supramolecular thermoresponsive behavior of fatty acid surfactant solutions

Optics Communications

Abstract The development and the ability of an optical integrated polymeric resonator, acting as ... more Abstract The development and the ability of an optical integrated polymeric resonator, acting as a surface light probe, for monitoring temperature-induced supramolecular phase transitions is presented in this work. The homogeneous detection of the transitions between different self-assembled structures in an aqueous solution of fatty acids (12-hydroxystearic acid, in association with amino-pentanol) was studied by investigating the coupling between the solution and the integrated photonic micro-cavity. Tuning the self-organized assemblies of surfactant is very attractive for many applications, such as cosmetic products, food, drug delivery and medical, and the development of alternative tools – especially those requiring minute amount of solution – to monitor their structural changes are essential. These original studies at temperatures ranging from 17 to 24 °C, based on a statistical treatment of optical resonance spectra, have evidenced the thermoresponsive nature of the optical features, and that different regimes occur with temperature. The optical results were corroborated with the measurement of the solution viscosity as a function of temperature, confirming that we can ascribe the optically-detected regimes to a surfactant assembly shifting reversibly from a tubular shape to a micellar one. The comparison between the optical and the rheological responses showed different accuracies: while the viscosity data exhibited a rather smooth and monotonous transition, the behavior changes were sharper and non-monotonous in terms of optical properties, allowing us to unambiguously identify in intermediate regime between 18.5 and 20 °C. These morphological transition experiments represent a unique opportunity to extend the numbers of available techniques studying these systems through integrated optical techniques with potential opportunities of real time detection and working on low sampling volume.

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Research paper thumbnail of Efficient active waveguiding properties of Mo6nano-cluster-doped polymer nanotubes

Nanotechnology, 2016

We investigate 1D nanostructures based on a Mo6@SU8 hybrid nanocomposite in which photoluminescen... more We investigate 1D nanostructures based on a Mo6@SU8 hybrid nanocomposite in which photoluminescent Mo6 clusters are embedded in the photosensitive SU8 resist. Tens of micrometers long Mo6@SU8-based tubular nanostructures were fabricated by the wetting template method, enabling the control of the inner and outer diameter to about 190 nm and 240 nm respectively, as supported by structural and optical characterizations. The image plane optical study of these nanotubes under optical pumping highlights the efficient waveguiding phenomenon of the red luminescence emitted by the clusters. Moreover, the wave vector distribution in the Fourier plane determined by leakage radiation microscopy gives additional features of the emission and waveguiding. First, the anisotropic red luminescence of the whole system can be attributed to the guided mode along the nanotube. Then, a low-loss propagation behavior is evidenced in the Mo6@SU8-based nanotubes. This result contrasts with the weaker waveguiding signature in the case of UV210-based nanotubes embedding PFO (poly(9,9-di-n-octylfluorenyl-2,7-diyl)). It is attributed to the strong reabsorption phenomenon, owing to overlapping between absorption and emission bands in the semi-conducting conjugated polymer PFO. These results make this Mo6@SU8 original class of nanocomposite a promising candidate as nanosources for submicronic photonic integration.

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Research paper thumbnail of A laterally coupled UV210 polymer racetrack micro-resonator for thermal tunability and glucose sensing capability

Advanced Device Materials, 2015

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Research paper thumbnail of Intégration et caractérisation de micro-résonateurs 2D et 3D en micro-optique

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Microsystèmes et capteurs opto-thermo-mécaniques sur matériaux polymères

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Research paper thumbnail of On the detection of nanoparticle cloud migration by a resonant photonic surface signal towards sedimentation velocity measurements

Results in Optics

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Research paper thumbnail of Determination of Stokes velocities and sedimentation rate by a photonic resonant surface signal

Optical Sensors 2021

The sedimentation of solid particles in a liquid is a physical phenomenon that necessitate to be ... more The sedimentation of solid particles in a liquid is a physical phenomenon that necessitate to be well understood and measured in several cases. In medical diagnosis, a knowledge of the sedimentation speed of red blood cells for example, allows the early diagnosis of various inflammations. In study, optical Micro-Resonators (MRs) are used as sensors to track the dynamical phenomenon of sedimentation of a cloud of nano-particles in water, and the associated consequences on the spectral characteristics of the guided mode are analyzed. A MR is characterized by its eigenvalue, namely the effective index of an optical mode propagating inside. A progressive modification of the environment thus induces a temporal variation of the effective index. Such a variation can be measured by the tracking of the Free Spectral Range (FSR) of the transduced spectra against time. The transduced optical signal is then directed towards an Optical Spectrum Analyzer (OSA) from which spectra are acquired against time. A millimeter tank filled with water is judiciously deposited on the surface of the chip, before the adding of the solution of nano-particles. The spectra are acquired during the whole duration of the process of sedimentation. The data collected this way are then compared to a simple theoretical model describing the sedimentation of a spherical particle in water. Moreover, the sedimentation theory and the derivation of the speed of sedimentation of a spherical particle is presented, plus the presentation of the experimental setup, from the fabrication of the photonic structure by photolithography, to the inclusion of this circuit in an optical characterization platform and the presentation of the data acquisition and treatment program. The experimental results are analyzed and discussed. The differences are around 10% over the theoretical Stokes velocities relating to such sedimentation process. An overall generic curve or spectral response is clearly demonstrated on these sedimentation processes.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of About monitoring the dynamics of phase transition in food and biology by micro-photonics: detecting soft-matter process

Integrated Photonics Platforms: Fundamental Research, Manufacturing and Applications, 2020

Bookmarks Related papers MentionsView impact

Research paper thumbnail of About the Heisenberg's uncertainty principle and the determination of effective optical indices in integrated photonics at high sub-wavelength regime

Optik - International Journal for Light and Electron Optics, 2016

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Marcatili’s extended approach: comparison to semi-vectorial methods applied to pedestal waveguide design

Journal of Optics A: Pure and Applied Optics, 2008

This paper deals with a theoretical study of pedestal waveguides. An extension of the Marcatili m... more This paper deals with a theoretical study of pedestal waveguides. An extension of the Marcatili method has been developed in order to adapt this analytical method to pedestal structures. Simulations are performed for two different T-pedestal waveguide (T-PW) configurations corresponding respectively to a high and a lower core to pedestal widths ratio (T-PW I and T-PW II). Each configuration is

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Native spider silk as a biological optical fiber

Applied Physics Letters, 2013

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Versatile Analytic Approach to Assessing Harmonic Distortion in Current Driven Electrodynamic Loudspeakers

Current-controlling loudspeakers has been investigated since a significant time and is known as q... more Current-controlling loudspeakers has been investigated since a significant time and is known as quite appreciated by demanding audiophiles. Today’s new market research clearly moves to investigate on adequate innovative designs together with simple theoretical solutions to deal with their residual non-linear properties. Hence, this paper aims to present a compact analytical approach allowing to synthesize the harmonic distortion hindering the audio quality of electrodynamic loudspeakers, while considering separately the influence of the changes of their main constitutive parameters. As a great convenience the relevant compact way to shape Taylor polynomials provides simple expressions describing the first five harmonic distortion lines on the whole spectrum: Proceeding so clearly highlights the critical influence of each given parameter. Besides consistency when compared with numerical analysis operated with the Simulink ® software, this approach may be easily implemented with a sta...

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Determination of a statistical lack of volume matter by resonance principle: experiential approach and modeling

In integrated photonics, the calculation of the solutions regarding the propagation equations mod... more In integrated photonics, the calculation of the solutions regarding the propagation equations modes may be summed up as a problem with eigenvalues and eigenvectors to be solved. Based on such global principle, we have investigated the ability to monitor the impact of a lack of material (or void) on the evolution of eigenvalues of waveguides. To this end, specific families of resonators have been designed with several slits nano-inscribed upon them. The signal resonant light is then characterized while considering the whole geometry taking account of the void: thus, it contains the information regarding the pre-defined recessed volume. The UV 210 polymer is processed (deep UV 248 nm) so as to shape specific slots within a set of waveguides. Then, such waveguides have been re-looped as micro-resonators circuits with a view to measuring experimentally relevant variations of the eigenvalue considering the Free Spectral Range (FSR) associated with resonances. Experiments allowed us to hi...

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Advantages of UV210 polymer for integrated optics applications: comparison of ridge and photoinscripted strip waveguide performances

Journal of Optics, 2015

We report on the propagation performance comparison of two waveguide structures obtained from the... more We report on the propagation performance comparison of two waveguide structures obtained from the same UV210 photoresist. Ridge waveguide structures were fabricated by deep ultraviolet photolithography, and photoinscripted strip waveguides were realized by the same process, excluding the last development step. Structural and optical studies were carried out for both waveguide families, highlighting a well-controlled photolithography process. Predictions of the propagating modes were also led using the beam propagation method, showing a good agreement with experiments in single-mode propagation. Propagation losses were evaluated at 635 nm by cut-back measurement, showing mean loss values that are slightly lower for photoinscripted waveguides than for ridge waveguides. UV210 photoinscripted waveguides thus combine a fast and low-cost process, reduced optical losses, and a planar surface with as many advantages for more complex integrated components.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Pristine spider silk fibers as waveguiding microstructure in free space and in an integrated photonic chip

2013 Conference on Lasers & Electro-Optics Europe & International Quantum Electronics Conference CLEO EUROPE/IQEC, 2013

ABSTRACT form only given. Silk fibers produced by nature are among the most interesting materials... more ABSTRACT form only given. Silk fibers produced by nature are among the most interesting materials. Besides their high degree of biocompatibility, they are bioresorbable, ecologically friendly, and offer excellent mechanical properties. In particular, silks of spider and worm have aroused a huge interest as seen by the large literature on their structural organization [1, 2]. Thanks to material engineering possibility [3, 4], regenerated worm silk has been intensively studied and used in different fields such as electronics and photonics [5, 6]. On the other hand, native silks fibers are utilized in textile applications and in surgery procedures but have not yet deserved attention for photonic applications. However, the exceptional mechanical properties of natural silk mainly originate from an elaborated hierarchical organization which has not yet been reproduced in regenerated silk.We demonstrate the promising optical fiber behavior of pristine dragline silk from the spider Nephila clavipes, as well as its integration in a photonic chip made of synthetic polymer microstructures patterned by UV-lithography. The spinning process of the native fiber leads to a diameter of 5 microns, homogeneous over long distances. Since silk manipulation is straightforward, optical propagation in straight and loop configurations has been validated. In free space, attenuation coefficient (propagation losses) and coupling losses were estimated by the cut-back method on straight fiber at 10.5 dB/cm and 10 dB, respectively.In addition, the integration of the pristine silk fiber on a photonic chip and working optical hybrid devices based on synthetic polymer and natural silk fibers were demonstrated. Fig. 1a) is a scanning electron microscope of a chip composed of native spider silk embedded in SU8 microstructures (disk-reservoirs MD1 and MD2) designed by UV-lithography7. During light injection in a SU8 waveguide connected to MD1, light propagates to MD1 where light is confined at the edge- of the disk. Fig. 1b is a micro-beam profile of the chip during light injection and shows that light is confined along the silk fiber and at the edges of MD2. This confirms the optical coupling between synthetic polymer microstructures and silk fiber. These results highlight the potential role of this unique material for biophotonic applications either in free space or in integrated chip for which light propagation and/or sensing in biocompatible media is needed.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of <title>New practical approach of integrated photonic based on biomimetic peptidic/silica self-assembled nanotubes</title>

Integrated Optics: Devices, Materials, and Technologies XIII, 2009

We report on the first developments for a new approach of integrated photonic using optical evane... more We report on the first developments for a new approach of integrated photonic using optical evanescent coupling from organic microstructures to bundles of hybrid nanotubes (NT). Microstructures are organic disks acting as photon reservoirs, integrated on a photonic chip fabricated by micro-technologic processes. Biomimetic peptidic/ silica nanotubes are realized by molecular self-assembly allowing high aspect ratio. Such heterostructures have been included directly on the organic chip as an innovative solution based on nanotubes in situ chipapproach. The latter allowed us to obtain an adequate evanescent coupling localized between micronic-disks and bundles of nanotubes. As a result, we highlight a specific photonic propagation along various heterostructured- NT-bundles featuring distances beyond the centimeter and losses from 1.2 to 6.6 dB/cm. It presents an advantageous confinement of the optical mode marked with strong energy localizations between nanotubes.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of First developments for photonics integrated on plasma-polymer-HMDSO: Single-mode TE00–TM00 straight waveguides

Optical Materials, 2007

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Un échafaudage de peptides pour fabriquer des nanotubes de silice: Une organisation très hiérarchique

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Hybrid composed method associating conformal transformation with matrix formulation for computing eigenvalues and eigenvectors in bended optical waveguides

Optik - International Journal for Light and Electron Optics, 2017

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Analysis of giant waveguide tapers with funnel geometry: multi-mode Interference regime to single mode

In this study, we are interested in giant tapers operating in a totally Multi-Mode Interference (... more In this study, we are interested in giant tapers operating in a totally Multi-Mode Interference (MMI) regime capable of producing still an adequate single-mode field at the output. The idea is therefore to provide an answer on a possible giant acceptable limit of such MMI tapers still causing a single-mode output and then determining which opto-geometric parameters on this simple mathematical object and geometry act on the behavior. To this end, we have defined energy criteria per volume at the output. We consider families of tapers with a constant height corresponding to the output rib waveguide and a triangle shape. Each taper is defined by its input size, its length and its output size. The objective is to determine the minimum length of the taper to get enough energy or the desired guided mode(s) in the output waveguide. Two various approaches have been investigated and compared: numerical simulations by a finite element method (COMSOL) and a pure mathematical and geometrical st...

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Microphotonics for monitoring the supramolecular thermoresponsive behavior of fatty acid surfactant solutions

Optics Communications

Abstract The development and the ability of an optical integrated polymeric resonator, acting as ... more Abstract The development and the ability of an optical integrated polymeric resonator, acting as a surface light probe, for monitoring temperature-induced supramolecular phase transitions is presented in this work. The homogeneous detection of the transitions between different self-assembled structures in an aqueous solution of fatty acids (12-hydroxystearic acid, in association with amino-pentanol) was studied by investigating the coupling between the solution and the integrated photonic micro-cavity. Tuning the self-organized assemblies of surfactant is very attractive for many applications, such as cosmetic products, food, drug delivery and medical, and the development of alternative tools – especially those requiring minute amount of solution – to monitor their structural changes are essential. These original studies at temperatures ranging from 17 to 24 °C, based on a statistical treatment of optical resonance spectra, have evidenced the thermoresponsive nature of the optical features, and that different regimes occur with temperature. The optical results were corroborated with the measurement of the solution viscosity as a function of temperature, confirming that we can ascribe the optically-detected regimes to a surfactant assembly shifting reversibly from a tubular shape to a micellar one. The comparison between the optical and the rheological responses showed different accuracies: while the viscosity data exhibited a rather smooth and monotonous transition, the behavior changes were sharper and non-monotonous in terms of optical properties, allowing us to unambiguously identify in intermediate regime between 18.5 and 20 °C. These morphological transition experiments represent a unique opportunity to extend the numbers of available techniques studying these systems through integrated optical techniques with potential opportunities of real time detection and working on low sampling volume.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Efficient active waveguiding properties of Mo6nano-cluster-doped polymer nanotubes

Nanotechnology, 2016

We investigate 1D nanostructures based on a Mo6@SU8 hybrid nanocomposite in which photoluminescen... more We investigate 1D nanostructures based on a Mo6@SU8 hybrid nanocomposite in which photoluminescent Mo6 clusters are embedded in the photosensitive SU8 resist. Tens of micrometers long Mo6@SU8-based tubular nanostructures were fabricated by the wetting template method, enabling the control of the inner and outer diameter to about 190 nm and 240 nm respectively, as supported by structural and optical characterizations. The image plane optical study of these nanotubes under optical pumping highlights the efficient waveguiding phenomenon of the red luminescence emitted by the clusters. Moreover, the wave vector distribution in the Fourier plane determined by leakage radiation microscopy gives additional features of the emission and waveguiding. First, the anisotropic red luminescence of the whole system can be attributed to the guided mode along the nanotube. Then, a low-loss propagation behavior is evidenced in the Mo6@SU8-based nanotubes. This result contrasts with the weaker waveguiding signature in the case of UV210-based nanotubes embedding PFO (poly(9,9-di-n-octylfluorenyl-2,7-diyl)). It is attributed to the strong reabsorption phenomenon, owing to overlapping between absorption and emission bands in the semi-conducting conjugated polymer PFO. These results make this Mo6@SU8 original class of nanocomposite a promising candidate as nanosources for submicronic photonic integration.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of A laterally coupled UV210 polymer racetrack micro-resonator for thermal tunability and glucose sensing capability

Advanced Device Materials, 2015

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Intégration et caractérisation de micro-résonateurs 2D et 3D en micro-optique

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Microsystèmes et capteurs opto-thermo-mécaniques sur matériaux polymères

Bookmarks Related papers MentionsView impact