The Experts below are selected from a list of 3792 Experts worldwide ranked by ideXlab platform
Ribal Georges Sabat - One of the best experts on this subject based on the ideXlab platform.
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photoactive passive molecular glass blends an efficient strategy to optimize azomaterials for surface relief grating inscription
ACS Applied Materials & Interfaces, 2017Co-Authors: Audrey Laventure, Ribal Georges Sabat, Olivier Lebel, Jeremie Bourotte, Jaana Vapaavuori, Lucas Karperien, Christian PellerinAbstract:Irradiation of azomaterials causes various photophysical and photomechanical effects that can be exploited for the preparation of functional materials such as surface relief gratings (SRGs). Herein, we develop and apply an efficient strategy to optimize the SRG inscription process by decoupling, for the first time, the important effects of the azo content and glass transition temperature (Tg). We prepare blends of a photoactive molecular glass functionalized with the azo Disperse Red 1 (gDR1) with a series of analogous photopassive molecular glasses. Blends with 10 and 40 mol % of gDR1 are completely miscible, present very similar optical properties, and cover a wide range of Tg from below to well above ambient temperature. SRG inscription experiments show that the diffraction efficiency (DE), residual DE, and initial inscription rate reach a maximum when Tg is 25–40 °C above ambient temperature for low to high azo content, respectively. Indeed, for a fixed 40 mol % azo content, choosing the optimal Tg en...
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laser induced controllable chirped pitch circular surface relief diffraction gratings on azo glass
Photonics Research, 2015Co-Authors: James Leibold, Ribal Georges SabatAbstract:Chirped-pitch nanoscale circular surface-relief diffraction gratings were photoinscribed on thin films of a Disperse Red 1 functionalized material using a holographic technique. A truncated conical mirror splits and Redirects a converging or diverging laser beam, resulting in an interference pattern of concentric circles with a chirped pitch that can be controlled by varying the wavefront curvature. The resulting circular gratings have a diameter of 12 mm and have the advantage of being produced in a fast, single-step procedure with no requirement for a master grating, photomask, or milling equipment.
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design and fabrication of constant pitch circular surface relief diffraction gratings on Disperse Red 1 glass
Optics Letters, 2014Co-Authors: James Leibold, Peter Snell, Olivier Lebel, Ribal Georges SabatAbstract:Circular surface-relief diffraction gratings with a constant pitch were photo-inscribed on thin films of a Disperse Red 1 functionalized glass-forming compound using a novel holographic technique. Various light-interfering metallic fixtures, which consisted of annular rings with a sloped and polished inner surface, were designed and fabricated. Each of them allowed the inscription of stable and high-quality circular diffraction gratings with pitches ranging from approximately 600–1400 nm and depths up to 250 nm. This was accomplished by exposure to a collimated laser beam with an irradiance of 604 mW/cm2 for 350 s. The resulting gratings had a diameter of 11.4 mm and had the advantage of being produced in a simple single-step procedure with no postprocessing or specialized equipment. The pitch and diameter of these circular gratings were dependent on the fixture geometry, while the depth was related to the exposure time.
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Disperse and disordeRed a mexylaminotriazine substituted azobenzene derivative with superior glass and surface relief grating formation
Journal of Materials Chemistry C, 2014Co-Authors: Ribal Georges Sabat, Jeanmichel Nunzi, Robert Kirby, Olivier LebelAbstract:Materials containing azobenzene chromophores exhibit photomechanical behaviors, including the formation of surface relief gratings (SRG) caused by irradiation with two interfering laser beams. While azo-functionalized polymers were extensively studied, small molecules offer the advantage of being monoDisperse species, which translates into easier synthesis and purification, as well as more uniform behavior. A drawback is that they tend to crystallize and do not always form high-quality thin films. Glass-forming compounds incorporating azobenzene were previously synthesized in several synthetic steps and in low yield. Herein, a Disperse Red 1 (DR1) functionalized with a mexylaminotriazine group is synthesized in 94% yield using a simple and straightforward procedure. It shows both the ability to form extremely stable glassy phases, and the ability to form SRG in the solid state with growth rates and grating heights closely similar to DR1-functionalized polymers.
James Leibold - One of the best experts on this subject based on the ideXlab platform.
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laser induced controllable chirped pitch circular surface relief diffraction gratings on azo glass
Photonics Research, 2015Co-Authors: James Leibold, Ribal Georges SabatAbstract:Chirped-pitch nanoscale circular surface-relief diffraction gratings were photoinscribed on thin films of a Disperse Red 1 functionalized material using a holographic technique. A truncated conical mirror splits and Redirects a converging or diverging laser beam, resulting in an interference pattern of concentric circles with a chirped pitch that can be controlled by varying the wavefront curvature. The resulting circular gratings have a diameter of 12 mm and have the advantage of being produced in a fast, single-step procedure with no requirement for a master grating, photomask, or milling equipment.
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design and fabrication of constant pitch circular surface relief diffraction gratings on Disperse Red 1 glass
Optics Letters, 2014Co-Authors: James Leibold, Peter Snell, Olivier Lebel, Ribal Georges SabatAbstract:Circular surface-relief diffraction gratings with a constant pitch were photo-inscribed on thin films of a Disperse Red 1 functionalized glass-forming compound using a novel holographic technique. Various light-interfering metallic fixtures, which consisted of annular rings with a sloped and polished inner surface, were designed and fabricated. Each of them allowed the inscription of stable and high-quality circular diffraction gratings with pitches ranging from approximately 600–1400 nm and depths up to 250 nm. This was accomplished by exposure to a collimated laser beam with an irradiance of 604 mW/cm2 for 350 s. The resulting gratings had a diameter of 11.4 mm and had the advantage of being produced in a simple single-step procedure with no postprocessing or specialized equipment. The pitch and diameter of these circular gratings were dependent on the fixture geometry, while the depth was related to the exposure time.
Olivier Lebel - One of the best experts on this subject based on the ideXlab platform.
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photoactive passive molecular glass blends an efficient strategy to optimize azomaterials for surface relief grating inscription
ACS Applied Materials & Interfaces, 2017Co-Authors: Audrey Laventure, Ribal Georges Sabat, Olivier Lebel, Jeremie Bourotte, Jaana Vapaavuori, Lucas Karperien, Christian PellerinAbstract:Irradiation of azomaterials causes various photophysical and photomechanical effects that can be exploited for the preparation of functional materials such as surface relief gratings (SRGs). Herein, we develop and apply an efficient strategy to optimize the SRG inscription process by decoupling, for the first time, the important effects of the azo content and glass transition temperature (Tg). We prepare blends of a photoactive molecular glass functionalized with the azo Disperse Red 1 (gDR1) with a series of analogous photopassive molecular glasses. Blends with 10 and 40 mol % of gDR1 are completely miscible, present very similar optical properties, and cover a wide range of Tg from below to well above ambient temperature. SRG inscription experiments show that the diffraction efficiency (DE), residual DE, and initial inscription rate reach a maximum when Tg is 25–40 °C above ambient temperature for low to high azo content, respectively. Indeed, for a fixed 40 mol % azo content, choosing the optimal Tg en...
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design and fabrication of constant pitch circular surface relief diffraction gratings on Disperse Red 1 glass
Optics Letters, 2014Co-Authors: James Leibold, Peter Snell, Olivier Lebel, Ribal Georges SabatAbstract:Circular surface-relief diffraction gratings with a constant pitch were photo-inscribed on thin films of a Disperse Red 1 functionalized glass-forming compound using a novel holographic technique. Various light-interfering metallic fixtures, which consisted of annular rings with a sloped and polished inner surface, were designed and fabricated. Each of them allowed the inscription of stable and high-quality circular diffraction gratings with pitches ranging from approximately 600–1400 nm and depths up to 250 nm. This was accomplished by exposure to a collimated laser beam with an irradiance of 604 mW/cm2 for 350 s. The resulting gratings had a diameter of 11.4 mm and had the advantage of being produced in a simple single-step procedure with no postprocessing or specialized equipment. The pitch and diameter of these circular gratings were dependent on the fixture geometry, while the depth was related to the exposure time.
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Disperse and disordeRed a mexylaminotriazine substituted azobenzene derivative with superior glass and surface relief grating formation
Journal of Materials Chemistry C, 2014Co-Authors: Ribal Georges Sabat, Jeanmichel Nunzi, Robert Kirby, Olivier LebelAbstract:Materials containing azobenzene chromophores exhibit photomechanical behaviors, including the formation of surface relief gratings (SRG) caused by irradiation with two interfering laser beams. While azo-functionalized polymers were extensively studied, small molecules offer the advantage of being monoDisperse species, which translates into easier synthesis and purification, as well as more uniform behavior. A drawback is that they tend to crystallize and do not always form high-quality thin films. Glass-forming compounds incorporating azobenzene were previously synthesized in several synthetic steps and in low yield. Herein, a Disperse Red 1 (DR1) functionalized with a mexylaminotriazine group is synthesized in 94% yield using a simple and straightforward procedure. It shows both the ability to form extremely stable glassy phases, and the ability to form SRG in the solid state with growth rates and grating heights closely similar to DR1-functionalized polymers.
Patrick Steglich - One of the best experts on this subject based on the ideXlab platform.
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on chip dispersion measurement of the quadratic electro optic effect in nonlinear optical polymers using a photonic integrated circuit technology
IEEE Photonics Journal, 2019Co-Authors: Patrick Steglich, Mauro Casalboni, Sigurd Schrader, Claus Villringer, Birgit Dietzel, Christian Mai, Andreas MaiAbstract:A novel method to determine the dispersion of the quadratic electro-optic effect in nonlinear optical materials by using a silicon-on-insulator microring resonator is presented. The microring consists of a silicon slot waveguide enabling large dc electric field strength at low applied voltages. The dispersion of third-order hyperpolarizability of a linear conjugated dye is approximated by using a two-level model for the off-resonant spectral region. As an example, the dispersion of the resonance wavelength of the resonator filled with a dye doped polymer was measuRed in dependence of the applied dc voltage. The polymer was poly (methylmethacrylate) doped with $\text{5 wt}\%$ Disperse Red 1 (DR1), and the measurements have been carried out at the telecommunication wavelength band around $\text{1550 nm}$ (optical C -band). The described measurements represent a new technique to determine the dispersion of the third-order susceptibility and molecular hyperpolarizability of the material filled into the slot of the ring-resonator.
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quadratic electro optic effect in silicon organic hybrid slot waveguides
Optics Letters, 2018Co-Authors: Patrick Steglich, Silvio Pulwer, Mauro Casalboni, Claus Villringer, Sigurd SchraderAbstract:: This Letter reports on the quadratic electro-optic effect of polymers, observed in a silicon slot-waveguide at low voltages. We demonstrate that in narrow slots, the electro-optic response with respect to refractive index change is strong enough for on-chip wavelength tuning and intensity modulation using voltages as low as 1 V. A silicon slot-waveguide embedded by a nonlinear optical polymer, consisting of the dye Disperse Red 1 in poly(methyl methacrylate), serves as the phase shifter in a racetrack ring resonator. As deduced from the experimental data, the third-order susceptibility of the utilized electro-optic polymer is about 2·10-19 m2/V2. The demonstrated low-voltage operation and inherently thermal stability show the potential for silicon-organic hybrid devices using the quadratic electro-optic effect.
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Comparative Study of Nano-Slot Silicon Waveguides CoveRed by Dye Doped and Undoped Polymer Cladding
MDPI AG, 2018Co-Authors: Siegfried Bondarenko, Claus Villringer, Patrick SteglichAbstract:Nonlinear optical dyes doped in optical polymer matrices are widely used for electro-optical devices. Linear optical properties change with dye concentration, which leads to a change in modal properties, especially in nano-structuRed integrated waveguides such as silicon slot-waveguides. Here, we investigate the influence of a nonlinear optical dye on the performance of a silicon-organic hybrid slot-waveguide. A simulation study of the modal and optical confinement properties is carried out and dependence of the structural parameters of the slot-waveguide and the organic cladding material is taken into account. As cladding material, a guest-host polymer system is employed comprising the nonlinear optical dye Disperse Red 1 (DR1) doped in a poly[methyl methacrylate] (PMMA) matrix. The refractive indices of doped and undoped PMMA were deduced from ellipsometric data. We present a guideline for an optimized slot-waveguide design for the fabrication in silicon-on-insulator technology giving rise to scalable, high-performance integrated electro-optical modulators
Sigurd Schrader - One of the best experts on this subject based on the ideXlab platform.
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on chip dispersion measurement of the quadratic electro optic effect in nonlinear optical polymers using a photonic integrated circuit technology
IEEE Photonics Journal, 2019Co-Authors: Patrick Steglich, Mauro Casalboni, Sigurd Schrader, Claus Villringer, Birgit Dietzel, Christian Mai, Andreas MaiAbstract:A novel method to determine the dispersion of the quadratic electro-optic effect in nonlinear optical materials by using a silicon-on-insulator microring resonator is presented. The microring consists of a silicon slot waveguide enabling large dc electric field strength at low applied voltages. The dispersion of third-order hyperpolarizability of a linear conjugated dye is approximated by using a two-level model for the off-resonant spectral region. As an example, the dispersion of the resonance wavelength of the resonator filled with a dye doped polymer was measuRed in dependence of the applied dc voltage. The polymer was poly (methylmethacrylate) doped with $\text{5 wt}\%$ Disperse Red 1 (DR1), and the measurements have been carried out at the telecommunication wavelength band around $\text{1550 nm}$ (optical C -band). The described measurements represent a new technique to determine the dispersion of the third-order susceptibility and molecular hyperpolarizability of the material filled into the slot of the ring-resonator.
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quadratic electro optic effect in silicon organic hybrid slot waveguides
Optics Letters, 2018Co-Authors: Patrick Steglich, Silvio Pulwer, Mauro Casalboni, Claus Villringer, Sigurd SchraderAbstract:: This Letter reports on the quadratic electro-optic effect of polymers, observed in a silicon slot-waveguide at low voltages. We demonstrate that in narrow slots, the electro-optic response with respect to refractive index change is strong enough for on-chip wavelength tuning and intensity modulation using voltages as low as 1 V. A silicon slot-waveguide embedded by a nonlinear optical polymer, consisting of the dye Disperse Red 1 in poly(methyl methacrylate), serves as the phase shifter in a racetrack ring resonator. As deduced from the experimental data, the third-order susceptibility of the utilized electro-optic polymer is about 2·10-19 m2/V2. The demonstrated low-voltage operation and inherently thermal stability show the potential for silicon-organic hybrid devices using the quadratic electro-optic effect.