Shigeru Yamaguchi - Academia.edu (original) (raw)
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Papers by Shigeru Yamaguchi
Journal of the Visualization Society of Japan, 1993
The Review of Laser Engineering
This paper reports the present status of laser diagnostics for trace dioxin detection. Opticalpro... more This paper reports the present status of laser diagnostics for trace dioxin detection. Opticalproperties such as infra-red (IR) absorption spectrum, ultraviolet (UV) pump frequencies , ionization potential of typical dioxins and their precursors as well as their generation process in an incinerator are reviewed. Candidates of available laser sources both in UV and IR realizing the trace detection system are briefly discussed taking account such optical database. Recent research activities for ultra-trace (-pptv) dioxins and their derivatives detection using laser sources focused on Resonance Enhanced Multi Photon Ionization with Time of Flight Mass Spectrometry (REMPI-TOFMS) method are also described.
Gas and chemical lasers remain the laser systems most easily scalable to very high energies and a... more Gas and chemical lasers remain the laser systems most easily scalable to very high energies and average powers including megawatt class lasers for military applications and tens of kilowatt class.
The development of scalable high power lasers in the UV-visible range and ultrashort high brightn... more The development of scalable high power lasers in the UV-visible range and ultrashort high brightness laser sources will have significant impact in a number of key technologies. Experiments of scaling the e-beam pumped XeF(C-,A) laser system to the 1 Joule/pulse output level at a 1 Hz repetition rate are described. Recent progress in the amplification of tunable ultrashort laser pulses in the visible spectrum, utilizing the broadband XeF(C-A) excimer transition, is also reported. 1. SCALING CHARACTERISTICS OF THE XeF(C-A) EXCIMER LASER Excimer lasers play an important role in many specific applications that utilize their unique characteristics such as high average power for material processing, and high spectral purity and broad band tunability for remote sensing, optical communication and basic physics research. There is considerable interest in the XeF(C-A)
High-Power Gas Lasers, 1990
ABSTRACT
Journal of Photopolymer Science and Technology
Machining of Fiber Reinforced Plastics (FRPs) were demonstrated using an intense excimer laser ra... more Machining of Fiber Reinforced Plastics (FRPs) were demonstrated using an intense excimer laser radiation at wavelengths of and 193 nm (ArF) and 308 nm (XeCl). Dependence of cutting performance on various parameters such as laser wavelengths, energy fluence, and pulse repetition frequency were investigated. For both wavelength, the removal rate was measured to be approximately 2 ,um/pulse with a minimum thermal degradation of the materials. The ablation threshold was greater than 0.5 J/cm2 at 193 nm. A considerably reduced threshold at 308 nm was found for the materials•taken up in this study. The cutting kerf processed by an excimer laser exhibits quite favorable for precise machining.
AIP Conference Proceedings, 2009
High-Power Lasers in Manufacturing, 2000
Titanium aluminide intermetallic compound is studied to find out good welding conditions using CO... more Titanium aluminide intermetallic compound is studied to find out good welding conditions using CO2 laser irradiation. In the experiment, we used the casting titanium aluminide containing iron, vanadium and boron with a thickness of 2 mm. We carried out bead-on-plate laser welding at various initial temperatures of specimens varied from room temperature to 873 [K] in inert gas environment filled with argon. We measured fused depth, bead width and Vickers hardness. As a result of experiments, welding speeds that allow full bead-on- plate welding to be possible were strongly by dependent on the initial temperature, 3000 [mm/min], initial temperature 873 [K], 2600 [mm/mm], initial temperature 673 [K], and 2000 [mm/min] with 300 [K]. Transverse crack-free welding was achieved, when initial temperature was at 873 [K].
Japanese Journal of Applied Physics Pt 1 Regular Papers Short Notes, Nov 15, 1999
ABSTRACT
Optical Review, Mar 1, 2010
We report progress in the design and fabrication of a monolithic, linearly polarized, pulsed, Yb-... more We report progress in the design and fabrication of a monolithic, linearly polarized, pulsed, Yb-doped fiber laser. This laser has a peak power of more than 100 kW, a tunable repetition rate from 100 kHz to 1 MHz, a tunable pulse duration from 2 ns to 2.5 ms, and a diffraction-limited, linearly polarized output beam with a mean power of 21 W and a wavelength of 1064 nm. A seed source that consists of a microchip Nd:YVO 4 laser and an electro optic deflector is developed. Using this source, the repetition rate and pulse duration are varied independently of each other. In addition, an excellent pulse-to-pulse repeatability is achieved. #
2013 Conference on Lasers & Electro-Optics Europe & International Quantum Electronics Conference CLEO EUROPE/IQEC, 2013
ABSTRACT High power pulsed lasers are used for industrial applications. The pulse width extends o... more ABSTRACT High power pulsed lasers are used for industrial applications. The pulse width extends over from the range of μs regime to fs regime, and the maximum repetition rate is around 100 MHz. A function in which pulse width and repetition rate can be changed independently is desired with many applications.
2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC), 2011
ABSTRACT Here, we report on a linearly polarized monolithic fiber amplifier system with a novel m... more ABSTRACT Here, we report on a linearly polarized monolithic fiber amplifier system with a novel master oscillator, which consists of a laser diode and electro optical (EO)-modulator.
Journal of Advanced Science, 1998
Initiatives of Precision Engineering at the Beginning of a Millennium, 2002
ABSTRACT
The Review of Laser Engineering, 2008
An optical method of temperature measurement to analyze CO 2 laser active medium based on near-in... more An optical method of temperature measurement to analyze CO 2 laser active medium based on near-infrared absorption spectroscopy with a 1.6-μm distributed-feedback (DFB) semiconductor laser is described in this paper. The method was used to measure gas temperatures in the range 400 K to 530 K for discharge electrode distances of 5 and 7.5 mm. Real-time temperature monitoring of CO 2 was achieved by using the DFB semiconductor laser. Such near-infrared absorption spectroscopy has the potential to be a practical method for diagnostic of the active medium of a CO 2 laser.
Proceedings of SPIE - The International Society for Optical Engineering
ABSTRACT
Journal of the Visualization Society of Japan, 1993
The Review of Laser Engineering
This paper reports the present status of laser diagnostics for trace dioxin detection. Opticalpro... more This paper reports the present status of laser diagnostics for trace dioxin detection. Opticalproperties such as infra-red (IR) absorption spectrum, ultraviolet (UV) pump frequencies , ionization potential of typical dioxins and their precursors as well as their generation process in an incinerator are reviewed. Candidates of available laser sources both in UV and IR realizing the trace detection system are briefly discussed taking account such optical database. Recent research activities for ultra-trace (-pptv) dioxins and their derivatives detection using laser sources focused on Resonance Enhanced Multi Photon Ionization with Time of Flight Mass Spectrometry (REMPI-TOFMS) method are also described.
Gas and chemical lasers remain the laser systems most easily scalable to very high energies and a... more Gas and chemical lasers remain the laser systems most easily scalable to very high energies and average powers including megawatt class lasers for military applications and tens of kilowatt class.
The development of scalable high power lasers in the UV-visible range and ultrashort high brightn... more The development of scalable high power lasers in the UV-visible range and ultrashort high brightness laser sources will have significant impact in a number of key technologies. Experiments of scaling the e-beam pumped XeF(C-,A) laser system to the 1 Joule/pulse output level at a 1 Hz repetition rate are described. Recent progress in the amplification of tunable ultrashort laser pulses in the visible spectrum, utilizing the broadband XeF(C-A) excimer transition, is also reported. 1. SCALING CHARACTERISTICS OF THE XeF(C-A) EXCIMER LASER Excimer lasers play an important role in many specific applications that utilize their unique characteristics such as high average power for material processing, and high spectral purity and broad band tunability for remote sensing, optical communication and basic physics research. There is considerable interest in the XeF(C-A)
High-Power Gas Lasers, 1990
ABSTRACT
Journal of Photopolymer Science and Technology
Machining of Fiber Reinforced Plastics (FRPs) were demonstrated using an intense excimer laser ra... more Machining of Fiber Reinforced Plastics (FRPs) were demonstrated using an intense excimer laser radiation at wavelengths of and 193 nm (ArF) and 308 nm (XeCl). Dependence of cutting performance on various parameters such as laser wavelengths, energy fluence, and pulse repetition frequency were investigated. For both wavelength, the removal rate was measured to be approximately 2 ,um/pulse with a minimum thermal degradation of the materials. The ablation threshold was greater than 0.5 J/cm2 at 193 nm. A considerably reduced threshold at 308 nm was found for the materials•taken up in this study. The cutting kerf processed by an excimer laser exhibits quite favorable for precise machining.
AIP Conference Proceedings, 2009
High-Power Lasers in Manufacturing, 2000
Titanium aluminide intermetallic compound is studied to find out good welding conditions using CO... more Titanium aluminide intermetallic compound is studied to find out good welding conditions using CO2 laser irradiation. In the experiment, we used the casting titanium aluminide containing iron, vanadium and boron with a thickness of 2 mm. We carried out bead-on-plate laser welding at various initial temperatures of specimens varied from room temperature to 873 [K] in inert gas environment filled with argon. We measured fused depth, bead width and Vickers hardness. As a result of experiments, welding speeds that allow full bead-on- plate welding to be possible were strongly by dependent on the initial temperature, 3000 [mm/min], initial temperature 873 [K], 2600 [mm/mm], initial temperature 673 [K], and 2000 [mm/min] with 300 [K]. Transverse crack-free welding was achieved, when initial temperature was at 873 [K].
Japanese Journal of Applied Physics Pt 1 Regular Papers Short Notes, Nov 15, 1999
ABSTRACT
Optical Review, Mar 1, 2010
We report progress in the design and fabrication of a monolithic, linearly polarized, pulsed, Yb-... more We report progress in the design and fabrication of a monolithic, linearly polarized, pulsed, Yb-doped fiber laser. This laser has a peak power of more than 100 kW, a tunable repetition rate from 100 kHz to 1 MHz, a tunable pulse duration from 2 ns to 2.5 ms, and a diffraction-limited, linearly polarized output beam with a mean power of 21 W and a wavelength of 1064 nm. A seed source that consists of a microchip Nd:YVO 4 laser and an electro optic deflector is developed. Using this source, the repetition rate and pulse duration are varied independently of each other. In addition, an excellent pulse-to-pulse repeatability is achieved. #
2013 Conference on Lasers & Electro-Optics Europe & International Quantum Electronics Conference CLEO EUROPE/IQEC, 2013
ABSTRACT High power pulsed lasers are used for industrial applications. The pulse width extends o... more ABSTRACT High power pulsed lasers are used for industrial applications. The pulse width extends over from the range of μs regime to fs regime, and the maximum repetition rate is around 100 MHz. A function in which pulse width and repetition rate can be changed independently is desired with many applications.
2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC), 2011
ABSTRACT Here, we report on a linearly polarized monolithic fiber amplifier system with a novel m... more ABSTRACT Here, we report on a linearly polarized monolithic fiber amplifier system with a novel master oscillator, which consists of a laser diode and electro optical (EO)-modulator.
Journal of Advanced Science, 1998
Initiatives of Precision Engineering at the Beginning of a Millennium, 2002
ABSTRACT
The Review of Laser Engineering, 2008
An optical method of temperature measurement to analyze CO 2 laser active medium based on near-in... more An optical method of temperature measurement to analyze CO 2 laser active medium based on near-infrared absorption spectroscopy with a 1.6-μm distributed-feedback (DFB) semiconductor laser is described in this paper. The method was used to measure gas temperatures in the range 400 K to 530 K for discharge electrode distances of 5 and 7.5 mm. Real-time temperature monitoring of CO 2 was achieved by using the DFB semiconductor laser. Such near-infrared absorption spectroscopy has the potential to be a practical method for diagnostic of the active medium of a CO 2 laser.
Proceedings of SPIE - The International Society for Optical Engineering
ABSTRACT