The Experts below are selected from a list of 2193 Experts worldwide ranked by ideXlab platform
Jodhbir S Mehta - One of the best experts on this subject based on the ideXlab platform.
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Clinical Ophthalmology 2012:6 1159–1168 Clinical Ophthalmology Comparison of outcomes of conventional WaveLight ® Allegretto Wave ® and Technolas®
2016Co-Authors: Daphne C Y Han, Jean Chen, Hla Myint Htoon, Donald T H Tan, Jodhbir S Mehta, Correspondence Jodhbir MehtaAbstract:Excimer Lasers in myopic laser in situ keratomileusi
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comparison of outcomes of conventional wavelight allegretto wave and technolas Excimer Lasers in myopic laser in situ keratomileusis
Clinical Ophthalmology, 2012Co-Authors: Daphne C Y Han, Jean Chen, Hla Myint Htoon, Donald T H Tan, Jodhbir S MehtaAbstract:Objective To compare the results of laser in situ keratomileusis for myopia using WaveLight® Allegretto Wave® Eye-Q® and Technolas® 217z Excimer Lasers.
Katsumi Midorikawa - One of the best experts on this subject based on the ideXlab platform.
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multiwavelength excitation processing using f2 and krf Excimer Lasers for precision microfabrication of hard materials
Applied Surface Science, 2002Co-Authors: Koji Sugioka, Koichi Toyoda, Kotaro Obata, Toshimitsu Akane, Katsumi MidorikawaAbstract:Vacuum ultraviolet (VUV)–ultraviolet (UV) multiwavelength excitation processing for precision microfabrication of hard materials, in which simultaneous irradiation of the VUV and the UV laser beams leads to high-quality ablation and highefficiency modification, is reviewed. A coaxial irradiation system of F2 and KrF Excimer Lasers has been developed. This system achieves well-defined micropatterning of fused silica and GaN with little thermal influence and little debris deposition. Ablation mechanism is explained as absorption of KrF Excimer laser by excited-states formed by F2 laser (excited-state absorption: ESA). Additionally, this technique is applied for more efficient refractive index modification of fused silica compared with single-F2 laser irradiation, which is attributed to resonance photoionization-like process based on ESA. The discussion includes characterization of optimum experimental conditions and features of the multiwavelength excitation processing. # 2002 Elsevier Science B.V. All rights reserved.
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efficient refractive index modification of fused silica by a resonance photoionization like process using f 2 and krf Excimer Lasers
Optics Letters, 2002Co-Authors: Kotaro Obata, Koji Sugioka, Toshimitsu Akane, Katsumi Midorikawa, Naoko Aoki, Koichi ToyodaAbstract:Novel materials processing by a multiwavelength excitation process using F2 and KrF Excimer Lasers for high-efficiency and high-speed refractive-index modification of fused silica is demonstrated. We find this process to be essentially superior to single-wavelength F2-laser processing: The multiwavelength excitation process achieves more than twice the diffraction efficiency of fused silica modified by a F2 laser at the same total number of photons in each irradiated laser beam supplied to the fused-silica substrate. This superiority is attributed to a resonance-photoionization-like process based on excited-state absorption.
Koichi Toyoda - One of the best experts on this subject based on the ideXlab platform.
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multiwavelength excitation processing using f2 and krf Excimer Lasers for precision microfabrication of hard materials
Applied Surface Science, 2002Co-Authors: Koji Sugioka, Koichi Toyoda, Kotaro Obata, Toshimitsu Akane, Katsumi MidorikawaAbstract:Vacuum ultraviolet (VUV)–ultraviolet (UV) multiwavelength excitation processing for precision microfabrication of hard materials, in which simultaneous irradiation of the VUV and the UV laser beams leads to high-quality ablation and highefficiency modification, is reviewed. A coaxial irradiation system of F2 and KrF Excimer Lasers has been developed. This system achieves well-defined micropatterning of fused silica and GaN with little thermal influence and little debris deposition. Ablation mechanism is explained as absorption of KrF Excimer laser by excited-states formed by F2 laser (excited-state absorption: ESA). Additionally, this technique is applied for more efficient refractive index modification of fused silica compared with single-F2 laser irradiation, which is attributed to resonance photoionization-like process based on ESA. The discussion includes characterization of optimum experimental conditions and features of the multiwavelength excitation processing. # 2002 Elsevier Science B.V. All rights reserved.
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efficient refractive index modification of fused silica by a resonance photoionization like process using f 2 and krf Excimer Lasers
Optics Letters, 2002Co-Authors: Kotaro Obata, Koji Sugioka, Toshimitsu Akane, Katsumi Midorikawa, Naoko Aoki, Koichi ToyodaAbstract:Novel materials processing by a multiwavelength excitation process using F2 and KrF Excimer Lasers for high-efficiency and high-speed refractive-index modification of fused silica is demonstrated. We find this process to be essentially superior to single-wavelength F2-laser processing: The multiwavelength excitation process achieves more than twice the diffraction efficiency of fused silica modified by a F2 laser at the same total number of photons in each irradiated laser beam supplied to the fused-silica substrate. This superiority is attributed to a resonance-photoionization-like process based on excited-state absorption.
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rapid formation of arsenic doped layer more than 1 0 μm deep in si using two krf Excimer Lasers
Japanese Journal of Applied Physics, 1995Co-Authors: Masayuki Jyumonji, Hiroshi Takai, Koji Sugioka, Koichi ToyodaAbstract:Sequential irradiation by two KrF Excimer Lasers (λ=248 nm) has been used to activate arsenic atoms implanted into Si substrates. The 1st laser pulse having 34 ns pulse width followed by the 2nd laser pulse of 23 ns after a time delay was irradiated to the sample. Laser fluences of the 1st laser pulse and the 2nd laser pulse were set at 2.4 J/cm 2 and 0.5 J/cm 2 , respectively. The substrate was heated to 700°C. From Rutherford backscattering spectroscopy (RBS) analysis, the depth of the doped layer is confirmed to be 1.0 μm. Severely rippled surface was observed by atomic force microscope (AFM) for the sample irradiated without the 2nd laser pulse, but the surface morphology can be improved by the sequential irradiation of two pulses. For a time delay of 150 ns, the minimum values of χ min (4.61%) and sheet resistance (41.43 Ω/ □) were obtained.
Kotaro Obata - One of the best experts on this subject based on the ideXlab platform.
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deep etching of epitaxial gallium nitride film by multiwavelength excitation process using f2 and krf Excimer Lasers
Applied Physics A, 2006Co-Authors: Kotaro Obata, Koji Sugioka, K Midorikawa, T Inamura, Hiroshi TakaiAbstract:The deep etching of GaN(0001) thin films epitaxially grown on Al2O3(0001) has been investigated by laser ablation using F2 and KrF Excimer Lasers. The simultaneous irradiation with F2 and KrF Excimer Lasers markedly improves etching quality compared with single-KrF Excimer laser ablation and provides almost the same quality as that in the case of single-F2 laser ablation with a high etching rate. Additionally, the present method achieves the deep etching of a GaN film of more than 5 μm in depth with steep side walls at an angle of 87° by changing the laser incidence angle.
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multiwavelength excitation processing using f2 and krf Excimer Lasers for precision microfabrication of hard materials
Applied Surface Science, 2002Co-Authors: Koji Sugioka, Koichi Toyoda, Kotaro Obata, Toshimitsu Akane, Katsumi MidorikawaAbstract:Vacuum ultraviolet (VUV)–ultraviolet (UV) multiwavelength excitation processing for precision microfabrication of hard materials, in which simultaneous irradiation of the VUV and the UV laser beams leads to high-quality ablation and highefficiency modification, is reviewed. A coaxial irradiation system of F2 and KrF Excimer Lasers has been developed. This system achieves well-defined micropatterning of fused silica and GaN with little thermal influence and little debris deposition. Ablation mechanism is explained as absorption of KrF Excimer laser by excited-states formed by F2 laser (excited-state absorption: ESA). Additionally, this technique is applied for more efficient refractive index modification of fused silica compared with single-F2 laser irradiation, which is attributed to resonance photoionization-like process based on ESA. The discussion includes characterization of optimum experimental conditions and features of the multiwavelength excitation processing. # 2002 Elsevier Science B.V. All rights reserved.
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efficient refractive index modification of fused silica by a resonance photoionization like process using f 2 and krf Excimer Lasers
Optics Letters, 2002Co-Authors: Kotaro Obata, Koji Sugioka, Toshimitsu Akane, Katsumi Midorikawa, Naoko Aoki, Koichi ToyodaAbstract:Novel materials processing by a multiwavelength excitation process using F2 and KrF Excimer Lasers for high-efficiency and high-speed refractive-index modification of fused silica is demonstrated. We find this process to be essentially superior to single-wavelength F2-laser processing: The multiwavelength excitation process achieves more than twice the diffraction efficiency of fused silica modified by a F2 laser at the same total number of photons in each irradiated laser beam supplied to the fused-silica substrate. This superiority is attributed to a resonance-photoionization-like process based on excited-state absorption.
Koji Sugioka - One of the best experts on this subject based on the ideXlab platform.
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deep etching of epitaxial gallium nitride film by multiwavelength excitation process using f2 and krf Excimer Lasers
Applied Physics A, 2006Co-Authors: Kotaro Obata, Koji Sugioka, K Midorikawa, T Inamura, Hiroshi TakaiAbstract:The deep etching of GaN(0001) thin films epitaxially grown on Al2O3(0001) has been investigated by laser ablation using F2 and KrF Excimer Lasers. The simultaneous irradiation with F2 and KrF Excimer Lasers markedly improves etching quality compared with single-KrF Excimer laser ablation and provides almost the same quality as that in the case of single-F2 laser ablation with a high etching rate. Additionally, the present method achieves the deep etching of a GaN film of more than 5 μm in depth with steep side walls at an angle of 87° by changing the laser incidence angle.
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multiwavelength excitation processing using f2 and krf Excimer Lasers for precision microfabrication of hard materials
Applied Surface Science, 2002Co-Authors: Koji Sugioka, Koichi Toyoda, Kotaro Obata, Toshimitsu Akane, Katsumi MidorikawaAbstract:Vacuum ultraviolet (VUV)–ultraviolet (UV) multiwavelength excitation processing for precision microfabrication of hard materials, in which simultaneous irradiation of the VUV and the UV laser beams leads to high-quality ablation and highefficiency modification, is reviewed. A coaxial irradiation system of F2 and KrF Excimer Lasers has been developed. This system achieves well-defined micropatterning of fused silica and GaN with little thermal influence and little debris deposition. Ablation mechanism is explained as absorption of KrF Excimer laser by excited-states formed by F2 laser (excited-state absorption: ESA). Additionally, this technique is applied for more efficient refractive index modification of fused silica compared with single-F2 laser irradiation, which is attributed to resonance photoionization-like process based on ESA. The discussion includes characterization of optimum experimental conditions and features of the multiwavelength excitation processing. # 2002 Elsevier Science B.V. All rights reserved.
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efficient refractive index modification of fused silica by a resonance photoionization like process using f 2 and krf Excimer Lasers
Optics Letters, 2002Co-Authors: Kotaro Obata, Koji Sugioka, Toshimitsu Akane, Katsumi Midorikawa, Naoko Aoki, Koichi ToyodaAbstract:Novel materials processing by a multiwavelength excitation process using F2 and KrF Excimer Lasers for high-efficiency and high-speed refractive-index modification of fused silica is demonstrated. We find this process to be essentially superior to single-wavelength F2-laser processing: The multiwavelength excitation process achieves more than twice the diffraction efficiency of fused silica modified by a F2 laser at the same total number of photons in each irradiated laser beam supplied to the fused-silica substrate. This superiority is attributed to a resonance-photoionization-like process based on excited-state absorption.
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rapid formation of arsenic doped layer more than 1 0 μm deep in si using two krf Excimer Lasers
Japanese Journal of Applied Physics, 1995Co-Authors: Masayuki Jyumonji, Hiroshi Takai, Koji Sugioka, Koichi ToyodaAbstract:Sequential irradiation by two KrF Excimer Lasers (λ=248 nm) has been used to activate arsenic atoms implanted into Si substrates. The 1st laser pulse having 34 ns pulse width followed by the 2nd laser pulse of 23 ns after a time delay was irradiated to the sample. Laser fluences of the 1st laser pulse and the 2nd laser pulse were set at 2.4 J/cm 2 and 0.5 J/cm 2 , respectively. The substrate was heated to 700°C. From Rutherford backscattering spectroscopy (RBS) analysis, the depth of the doped layer is confirmed to be 1.0 μm. Severely rippled surface was observed by atomic force microscope (AFM) for the sample irradiated without the 2nd laser pulse, but the surface morphology can be improved by the sequential irradiation of two pulses. For a time delay of 150 ns, the minimum values of χ min (4.61%) and sheet resistance (41.43 Ω/ □) were obtained.
