The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Philip St J Russell - One of the best experts on this subject based on the ideXlab platform.
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coherent intramodal Raman Gain suppression at high pump intensities in gas filled photonic crystal fibres
European Quantum Electronics Conference, 2017Co-Authors: Pooria Hosseini, Manoj K Mridha, David Novoa, Amir Abdolvand, Philip St J RussellAbstract:Stimulated Raman scattering is coherently suppressed if the rate of phonon creation is exactly balanced by the rate of phonon annihilation, a prediction first made by Bloembergen and Shen in 1964 [1]. Viewed classically, this occurs when the fringe patterns created by the interference of pump-Stokes and pump-anti-Stokes signals cancel each other out. It has been recently shown that gas-filled hollow-core photonic crystal fiber (HC-PCF), pumped in the vicinity of the zero-dispersion point (ZDP), is an ideal vehicle for observing Gain suppression. The ultralong path-lengths and the well-controlled dispersion permit dramatic suppression of the effective intramodal Raman Gain for the fundamental core mode [2, 3], resulting in strong enhancement of intermodal scattering from the pump to a Stokes signal in a higher-order core mode.
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universality of coherent Raman Gain suppression in gas filled broadband guiding photonic crystal fibers
Physical review applied, 2017Co-Authors: Pooria Hosseini, Manoj K Mridha, David Novoa, Amir Abdolvand, Philip St J RussellAbstract:The authors show that for $a\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}y$ hollow photonic crystal fiber filled with a gas, stimulated Raman scattering can be impaired by coherent Gain suppression, due to strong coupling between the interacting optical fields. This effect is worse at higher pumping intensities and, counterintuitively, higher frequencies. These results are important for designing fiber-based Raman shifters, amplifiers, and frequency combs, especially in the ultraviolet region, where the Raman Gain is high.
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coherent Raman Gain suppression in a gas filled hollow core pcf pumped in the deep ultraviolet
Conference on Lasers and Electro-Optics, 2016Co-Authors: David Novoa, Manoj K Mridha, S T Bauerschmidt, Philip St J RussellAbstract:DUV-pumped hydrogen-filled kagome-PCF displays coherent Raman Gain suppression at much higher values of dephasing than for visible pumping. This will impair the performance of gas-based Raman amplifiers and lasers, especially at higher pump powers.
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dramatic Raman Gain suppression in the vicinity of the zero dispersion point in a gas filled hollow core photonic crystal fiber
Physical Review Letters, 2015Co-Authors: S T Bauerschmidt, David Novoa, Philip St J RussellAbstract:In 1964 Bloembergen and Shen predicted that Raman Gain could be suppressed if the rates of phonon creation and annihilation (by inelastic scattering) exactly balance. This is only possible if the momentum required for each process is identical, i.e., phonon coherence waves created by pump-to-Stokes scattering are identical to those annihilated in pump-to-anti-Stokes scattering. In bulk gas cells, this can only be achieved over limited interaction lengths at an oblique angle to the pump axis. Here we report a simple system that provides dramatic Raman Gain suppression over long collinear path lengths in hydrogen. It consists of a gas-filled hollow-core photonic crystal fiber whose zero dispersion point is pressure adjusted to lie close to the pump laser wavelength. At a certain precise pressure, stimulated generation of Stokes light in the fundamental mode is completely suppressed, allowing other much weaker phenomena such as spontaneous Raman scattering to be explored at high pump powers.
Clara Rivero - One of the best experts on this subject based on the ideXlab platform.
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Raman Gain of selected tellurite glasses for IR fibre lasers calculated from spontaneous scattering spectra
Optical Materials, 2008Co-Authors: M. D. O'donnell, Clara Rivero, Kathleen Richardson, Thierry Cardinal, Michel Couzi, R Stolen, D Furniss, A B SeddonAbstract:In this paper, we present the spontaneous Raman scattering spectra and calculated Raman Gain spectra of two TZN (TeO2-ZnO-Na2O) glasses and three tungsten tellurite glasses. Addition of lead(II) oxide to the TZN glass increased the amount of lower coordination [TeO3]/[TeO3+1] units (765 cm-1) in the glass, and decreased the higher coordination [TeO4] units (665 cm-1) and Te-O-Te chains (440 cm-1). Addition of WO3 to the tungsten-tellurite glasses also resulted in the same trend as with PbO, and an additional band at around 925 cm-1 was seen to increase in intensity due to [WO4+2] units. Finally, a band at around 370 cm-1 was seen in the bismuth-doped tungsten tellurite glass, due to Te-O-Bi linkages. The calculated Raman Gain of these tellurite glasses were found to be 20-30 times that of fused-silica (0.89 × 10-13 m W-1). The calculated Raman Gain of the PbO-doped TZN glass also showed good agreement with direct Gain measurements previously made at 1064 nm. The minimum laser powers required to stimulate Raman amplification were calculated for one TZN glass and one tungsten-tellurite glass for optical fibre with a 10 μm core. The power densities required were of the order of MW cm-2 for fibre with 2-3 dB m-1 loss at 1550 nm and much lower than the surface optical damage thresholds of the glasses which are of the order of GW cm-2.
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tellurite and fluorotellurite glasses for fiberoptic Raman amplifiers glass characterization optical properties Raman Gain preliminary fiberization and fiber characterization
Journal of the American Ceramic Society, 2007Co-Authors: M D Odonnell, Clara Rivero, Kathleen Richardson, Robert Stegeman, R Stolen, A B Seddon, D Furniss, V K Tikhomirov, Mark Ramme, G I StegemanAbstract:In this study we report the physical properties and spontaneous Raman scattering spectra of nine oxide tellurite and fluorotellurite glasses from three glass systems—sodium–zinc–tellurite (TZN), tungsten–tellurite, and fluorotellurite. Raman Gain and surface damage threshold at 1064 nm are also shown for a selection of these glasses, which all exhibited high Gain and damage resistance. Raman Gain spectra were directly measured and accurately calculated for selected TZN and fluorotellurite glasses after Fresnel, internal solid angle, and Bose–Einstein corrections. The calculated Gain showed good fits to the Raman Gain measurements made using a calibrated nonlinear optics apparatus. Infrared and UV-Vis absorption spectra, characteristic temperatures obtained by differential thermal analysis, densities acquired by the Archimedes principle and refractive indices measured by spectroscopic ellipsometry are also given. The ternary systems TeO2–WO3–Bi2O3 and TeO2–Na2O–ZnF2 and the quaternary system TeO2–Na2O–ZnO–PbO show promise as Raman amplifiers as they are relatively easy to draw into optical fiber and to these authors' knowledge, this is the first time Raman Gain has been presented on halide containing tellurite glasses. The oxyfluoride system studied here, TeO2–Na2O–ZnF2, exhibited a dependence on the peak Raman intensity with ZnF2 addition. Calculations of preform geometry for mono- and multimode guidance and stresses in similar and dissimilar (core suction) core–clad pairs are shown. Dispersion in the mid-infrared and initial fiber drawing studies are also reported with fibers showing reasonable unclad losses.
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resolved discrepancies between visible spontaneous Raman cross section and direct near infrared Raman Gain measurements in teo2 based glasses
Optics Express, 2005Co-Authors: Clara Rivero, Kathleen Richardson, Robert Stegeman, Thierry Cardinal, M Couzi, David Talaga, G I StegemanAbstract:Disagreements on the Raman Gain response of different tellurite-based glasses, measured at different wavelengths, have been recently reported in the literature. In order to resolve this controversy, a multi-wavelength Raman cross-section experiment was conducted on two different TeO2-based glass samples. The estimated Raman Gain response of the material shows good agreement with the directly-measured Raman Gain data at 1064 nm, after correction for the dispersion and wavelength-dependence of the Raman Gain process.
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Quantifying Raman Gain coefficients in tellurite glasses
Journal of Non-crystalline Solids, 2004Co-Authors: Clara Rivero, Kathleen Richardson, Robert Stegeman, George I. Stegeman, Thierry Cardinal, Evelyne Fargin, Michel Couzi, Vincent RodriguezAbstract:This paper presents results obtained on bulk glasses that have been fabricated and characterized for their Raman Gain properties. We summarize relative values of the Raman Gain coefficients of different tellurite-based glasses as compared to that of fused silica, and compare data to values estimated from their Raman cross-section data. Spontaneous Raman spectra measurements demonstrate a straight forward means to estimate Raman Gain coefficients utilizing spontaneous Raman scattering cross-section data as referenced to known standards. This technique shows, for an initial set of tellurite-based bulk glass samples, excellent agreement with experimentally-obtained Raman Gain coefficient data. Initial experimental measurement of Raman Gain coefficients for several tellurite glasses reveal that some compositions examined exhibit an absolute Raman Gain coefficient up to 30 times higher than silica, with an overall spectral bandwidth more than twice that of fused silica.
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Tellurite glasses with peak absolute Raman Gain coefficients up to 30 times that of fused silica
Optics Letters, 2003Co-Authors: Robert Stegeman, Clara Rivero, Kathleen Richardson, Ladislav Jankovic, Hongki Kim, George Stegeman, Peter Delfyett, Yu Guo, Alfons Schulte, Thierry CardinalAbstract:An experimental system has been assembled to measure the absolute values of the Raman Gain spectrum for millimeter-thick glass samples. Results are reported for two new oxide glasses with Raman Gain coefficients as much as 30 times larger than that of fused silica and more than twice its spectral coverage.
Thierry Cardinal - One of the best experts on this subject based on the ideXlab platform.
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Raman Gain of selected tellurite glasses for IR fibre lasers calculated from spontaneous scattering spectra
Optical Materials, 2008Co-Authors: M. D. O'donnell, Clara Rivero, Kathleen Richardson, Thierry Cardinal, Michel Couzi, R Stolen, D Furniss, A B SeddonAbstract:In this paper, we present the spontaneous Raman scattering spectra and calculated Raman Gain spectra of two TZN (TeO2-ZnO-Na2O) glasses and three tungsten tellurite glasses. Addition of lead(II) oxide to the TZN glass increased the amount of lower coordination [TeO3]/[TeO3+1] units (765 cm-1) in the glass, and decreased the higher coordination [TeO4] units (665 cm-1) and Te-O-Te chains (440 cm-1). Addition of WO3 to the tungsten-tellurite glasses also resulted in the same trend as with PbO, and an additional band at around 925 cm-1 was seen to increase in intensity due to [WO4+2] units. Finally, a band at around 370 cm-1 was seen in the bismuth-doped tungsten tellurite glass, due to Te-O-Bi linkages. The calculated Raman Gain of these tellurite glasses were found to be 20-30 times that of fused-silica (0.89 × 10-13 m W-1). The calculated Raman Gain of the PbO-doped TZN glass also showed good agreement with direct Gain measurements previously made at 1064 nm. The minimum laser powers required to stimulate Raman amplification were calculated for one TZN glass and one tungsten-tellurite glass for optical fibre with a 10 μm core. The power densities required were of the order of MW cm-2 for fibre with 2-3 dB m-1 loss at 1550 nm and much lower than the surface optical damage thresholds of the glasses which are of the order of GW cm-2.
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resolved discrepancies between visible spontaneous Raman cross section and direct near infrared Raman Gain measurements in teo2 based glasses
Optics Express, 2005Co-Authors: Clara Rivero, Kathleen Richardson, Robert Stegeman, Thierry Cardinal, M Couzi, David Talaga, G I StegemanAbstract:Disagreements on the Raman Gain response of different tellurite-based glasses, measured at different wavelengths, have been recently reported in the literature. In order to resolve this controversy, a multi-wavelength Raman cross-section experiment was conducted on two different TeO2-based glass samples. The estimated Raman Gain response of the material shows good agreement with the directly-measured Raman Gain data at 1064 nm, after correction for the dispersion and wavelength-dependence of the Raman Gain process.
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Quantifying Raman Gain coefficients in tellurite glasses
Journal of Non-crystalline Solids, 2004Co-Authors: Clara Rivero, Kathleen Richardson, Robert Stegeman, George I. Stegeman, Thierry Cardinal, Evelyne Fargin, Michel Couzi, Vincent RodriguezAbstract:This paper presents results obtained on bulk glasses that have been fabricated and characterized for their Raman Gain properties. We summarize relative values of the Raman Gain coefficients of different tellurite-based glasses as compared to that of fused silica, and compare data to values estimated from their Raman cross-section data. Spontaneous Raman spectra measurements demonstrate a straight forward means to estimate Raman Gain coefficients utilizing spontaneous Raman scattering cross-section data as referenced to known standards. This technique shows, for an initial set of tellurite-based bulk glass samples, excellent agreement with experimentally-obtained Raman Gain coefficient data. Initial experimental measurement of Raman Gain coefficients for several tellurite glasses reveal that some compositions examined exhibit an absolute Raman Gain coefficient up to 30 times higher than silica, with an overall spectral bandwidth more than twice that of fused silica.
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Tellurite glasses with peak absolute Raman Gain coefficients up to 30 times that of fused silica
Optics Letters, 2003Co-Authors: Robert Stegeman, Clara Rivero, Kathleen Richardson, Ladislav Jankovic, Hongki Kim, George Stegeman, Peter Delfyett, Yu Guo, Alfons Schulte, Thierry CardinalAbstract:An experimental system has been assembled to measure the absolute values of the Raman Gain spectrum for millimeter-thick glass samples. Results are reported for two new oxide glasses with Raman Gain coefficients as much as 30 times larger than that of fused silica and more than twice its spectral coverage.
Kathleen Richardson - One of the best experts on this subject based on the ideXlab platform.
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Raman Gain of selected tellurite glasses for IR fibre lasers calculated from spontaneous scattering spectra
Optical Materials, 2008Co-Authors: M. D. O'donnell, Clara Rivero, Kathleen Richardson, Thierry Cardinal, Michel Couzi, R Stolen, D Furniss, A B SeddonAbstract:In this paper, we present the spontaneous Raman scattering spectra and calculated Raman Gain spectra of two TZN (TeO2-ZnO-Na2O) glasses and three tungsten tellurite glasses. Addition of lead(II) oxide to the TZN glass increased the amount of lower coordination [TeO3]/[TeO3+1] units (765 cm-1) in the glass, and decreased the higher coordination [TeO4] units (665 cm-1) and Te-O-Te chains (440 cm-1). Addition of WO3 to the tungsten-tellurite glasses also resulted in the same trend as with PbO, and an additional band at around 925 cm-1 was seen to increase in intensity due to [WO4+2] units. Finally, a band at around 370 cm-1 was seen in the bismuth-doped tungsten tellurite glass, due to Te-O-Bi linkages. The calculated Raman Gain of these tellurite glasses were found to be 20-30 times that of fused-silica (0.89 × 10-13 m W-1). The calculated Raman Gain of the PbO-doped TZN glass also showed good agreement with direct Gain measurements previously made at 1064 nm. The minimum laser powers required to stimulate Raman amplification were calculated for one TZN glass and one tungsten-tellurite glass for optical fibre with a 10 μm core. The power densities required were of the order of MW cm-2 for fibre with 2-3 dB m-1 loss at 1550 nm and much lower than the surface optical damage thresholds of the glasses which are of the order of GW cm-2.
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tellurite and fluorotellurite glasses for fiberoptic Raman amplifiers glass characterization optical properties Raman Gain preliminary fiberization and fiber characterization
Journal of the American Ceramic Society, 2007Co-Authors: M D Odonnell, Clara Rivero, Kathleen Richardson, Robert Stegeman, R Stolen, A B Seddon, D Furniss, V K Tikhomirov, Mark Ramme, G I StegemanAbstract:In this study we report the physical properties and spontaneous Raman scattering spectra of nine oxide tellurite and fluorotellurite glasses from three glass systems—sodium–zinc–tellurite (TZN), tungsten–tellurite, and fluorotellurite. Raman Gain and surface damage threshold at 1064 nm are also shown for a selection of these glasses, which all exhibited high Gain and damage resistance. Raman Gain spectra were directly measured and accurately calculated for selected TZN and fluorotellurite glasses after Fresnel, internal solid angle, and Bose–Einstein corrections. The calculated Gain showed good fits to the Raman Gain measurements made using a calibrated nonlinear optics apparatus. Infrared and UV-Vis absorption spectra, characteristic temperatures obtained by differential thermal analysis, densities acquired by the Archimedes principle and refractive indices measured by spectroscopic ellipsometry are also given. The ternary systems TeO2–WO3–Bi2O3 and TeO2–Na2O–ZnF2 and the quaternary system TeO2–Na2O–ZnO–PbO show promise as Raman amplifiers as they are relatively easy to draw into optical fiber and to these authors' knowledge, this is the first time Raman Gain has been presented on halide containing tellurite glasses. The oxyfluoride system studied here, TeO2–Na2O–ZnF2, exhibited a dependence on the peak Raman intensity with ZnF2 addition. Calculations of preform geometry for mono- and multimode guidance and stresses in similar and dissimilar (core suction) core–clad pairs are shown. Dispersion in the mid-infrared and initial fiber drawing studies are also reported with fibers showing reasonable unclad losses.
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resolved discrepancies between visible spontaneous Raman cross section and direct near infrared Raman Gain measurements in teo2 based glasses
Optics Express, 2005Co-Authors: Clara Rivero, Kathleen Richardson, Robert Stegeman, Thierry Cardinal, M Couzi, David Talaga, G I StegemanAbstract:Disagreements on the Raman Gain response of different tellurite-based glasses, measured at different wavelengths, have been recently reported in the literature. In order to resolve this controversy, a multi-wavelength Raman cross-section experiment was conducted on two different TeO2-based glass samples. The estimated Raman Gain response of the material shows good agreement with the directly-measured Raman Gain data at 1064 nm, after correction for the dispersion and wavelength-dependence of the Raman Gain process.
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Quantifying Raman Gain coefficients in tellurite glasses
Journal of Non-crystalline Solids, 2004Co-Authors: Clara Rivero, Kathleen Richardson, Robert Stegeman, George I. Stegeman, Thierry Cardinal, Evelyne Fargin, Michel Couzi, Vincent RodriguezAbstract:This paper presents results obtained on bulk glasses that have been fabricated and characterized for their Raman Gain properties. We summarize relative values of the Raman Gain coefficients of different tellurite-based glasses as compared to that of fused silica, and compare data to values estimated from their Raman cross-section data. Spontaneous Raman spectra measurements demonstrate a straight forward means to estimate Raman Gain coefficients utilizing spontaneous Raman scattering cross-section data as referenced to known standards. This technique shows, for an initial set of tellurite-based bulk glass samples, excellent agreement with experimentally-obtained Raman Gain coefficient data. Initial experimental measurement of Raman Gain coefficients for several tellurite glasses reveal that some compositions examined exhibit an absolute Raman Gain coefficient up to 30 times higher than silica, with an overall spectral bandwidth more than twice that of fused silica.
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Tellurite glasses with peak absolute Raman Gain coefficients up to 30 times that of fused silica
Optics Letters, 2003Co-Authors: Robert Stegeman, Clara Rivero, Kathleen Richardson, Ladislav Jankovic, Hongki Kim, George Stegeman, Peter Delfyett, Yu Guo, Alfons Schulte, Thierry CardinalAbstract:An experimental system has been assembled to measure the absolute values of the Raman Gain spectrum for millimeter-thick glass samples. Results are reported for two new oxide glasses with Raman Gain coefficients as much as 30 times larger than that of fused silica and more than twice its spectral coverage.
Robert Stegeman - One of the best experts on this subject based on the ideXlab platform.
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tellurite and fluorotellurite glasses for fiberoptic Raman amplifiers glass characterization optical properties Raman Gain preliminary fiberization and fiber characterization
Journal of the American Ceramic Society, 2007Co-Authors: M D Odonnell, Clara Rivero, Kathleen Richardson, Robert Stegeman, R Stolen, A B Seddon, D Furniss, V K Tikhomirov, Mark Ramme, G I StegemanAbstract:In this study we report the physical properties and spontaneous Raman scattering spectra of nine oxide tellurite and fluorotellurite glasses from three glass systems—sodium–zinc–tellurite (TZN), tungsten–tellurite, and fluorotellurite. Raman Gain and surface damage threshold at 1064 nm are also shown for a selection of these glasses, which all exhibited high Gain and damage resistance. Raman Gain spectra were directly measured and accurately calculated for selected TZN and fluorotellurite glasses after Fresnel, internal solid angle, and Bose–Einstein corrections. The calculated Gain showed good fits to the Raman Gain measurements made using a calibrated nonlinear optics apparatus. Infrared and UV-Vis absorption spectra, characteristic temperatures obtained by differential thermal analysis, densities acquired by the Archimedes principle and refractive indices measured by spectroscopic ellipsometry are also given. The ternary systems TeO2–WO3–Bi2O3 and TeO2–Na2O–ZnF2 and the quaternary system TeO2–Na2O–ZnO–PbO show promise as Raman amplifiers as they are relatively easy to draw into optical fiber and to these authors' knowledge, this is the first time Raman Gain has been presented on halide containing tellurite glasses. The oxyfluoride system studied here, TeO2–Na2O–ZnF2, exhibited a dependence on the peak Raman intensity with ZnF2 addition. Calculations of preform geometry for mono- and multimode guidance and stresses in similar and dissimilar (core suction) core–clad pairs are shown. Dispersion in the mid-infrared and initial fiber drawing studies are also reported with fibers showing reasonable unclad losses.
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resolved discrepancies between visible spontaneous Raman cross section and direct near infrared Raman Gain measurements in teo2 based glasses
Optics Express, 2005Co-Authors: Clara Rivero, Kathleen Richardson, Robert Stegeman, Thierry Cardinal, M Couzi, David Talaga, G I StegemanAbstract:Disagreements on the Raman Gain response of different tellurite-based glasses, measured at different wavelengths, have been recently reported in the literature. In order to resolve this controversy, a multi-wavelength Raman cross-section experiment was conducted on two different TeO2-based glass samples. The estimated Raman Gain response of the material shows good agreement with the directly-measured Raman Gain data at 1064 nm, after correction for the dispersion and wavelength-dependence of the Raman Gain process.
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Quantifying Raman Gain coefficients in tellurite glasses
Journal of Non-crystalline Solids, 2004Co-Authors: Clara Rivero, Kathleen Richardson, Robert Stegeman, George I. Stegeman, Thierry Cardinal, Evelyne Fargin, Michel Couzi, Vincent RodriguezAbstract:This paper presents results obtained on bulk glasses that have been fabricated and characterized for their Raman Gain properties. We summarize relative values of the Raman Gain coefficients of different tellurite-based glasses as compared to that of fused silica, and compare data to values estimated from their Raman cross-section data. Spontaneous Raman spectra measurements demonstrate a straight forward means to estimate Raman Gain coefficients utilizing spontaneous Raman scattering cross-section data as referenced to known standards. This technique shows, for an initial set of tellurite-based bulk glass samples, excellent agreement with experimentally-obtained Raman Gain coefficient data. Initial experimental measurement of Raman Gain coefficients for several tellurite glasses reveal that some compositions examined exhibit an absolute Raman Gain coefficient up to 30 times higher than silica, with an overall spectral bandwidth more than twice that of fused silica.
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Tellurite glasses with peak absolute Raman Gain coefficients up to 30 times that of fused silica
Optics Letters, 2003Co-Authors: Robert Stegeman, Clara Rivero, Kathleen Richardson, Ladislav Jankovic, Hongki Kim, George Stegeman, Peter Delfyett, Yu Guo, Alfons Schulte, Thierry CardinalAbstract:An experimental system has been assembled to measure the absolute values of the Raman Gain spectrum for millimeter-thick glass samples. Results are reported for two new oxide glasses with Raman Gain coefficients as much as 30 times larger than that of fused silica and more than twice its spectral coverage.
