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32 巻, 3 号
選択された号の論文の13件中1～13を表示しています
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レーザー解説
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山本 和久2004 年 32 巻 3 号 p. 152-153
発行日: 2004年
公開日: 2008/01/21
ジャーナル フリーPDF形式でダウンロード (143K) -
栖原 敏明, 藤村 昌寿2004 年 32 巻 3 号 p. 154-159
発行日: 2004年
公開日: 2008/01/21
ジャーナル フリーRecent progress in waveguide-type quasi-phase matched (QPM) nonlinear-optic wavelength conversion devices is reviewed with emphasis on research work of the author's group. A new technique for forming periodic domain-inverted structures in optical-damage-resistant MgO:LiNbO3 crystal is presented. Improvements of conversion efficiencies of QPM second-harmonic generation (SHG) and difference-frequency generation (DFG) devices are demonstrated. Experimental works toward applications to photonic network systems are reviewed, including those with the cascaded SHG-DFG wavelength conversion as well as the fundamental DFG wavelength conversion.抄録全体を表示PDF形式でダウンロード (534K) -
水内 公典, 山本 和久2004 年 32 巻 3 号 p. 160-164
発行日: 2004年
公開日: 2008/01/21
ジャーナル フリーQuasi-phase matched (QPM) second-harmonic generation (SHG) device offers various application for blue and ultra-violet (UV) radiations. Advanced poling technology made it possible to realize micron and sub-micron poling geometry in efficient nonlinear materials. Using these techniques, first-order nonlinear gratings have been realized for high power blue and UV SHG. Based on these devices, high power short wavelength laser sources were demonstrated for practical use. Recent progress in this area is reviewed with emphasis on research work of the author's group using bulk and waveguide QPM devices.抄録全体を表示PDF形式でダウンロード (476K) -
森本 朗裕, 和田 泰輔2004 年 32 巻 3 号 p. 165-169
発行日: 2004年
公開日: 2008/01/21
ジャーナル フリーPolarization reversal of an electro-optic crystal makes spatial control of the modulation polarity in the crystal. Electro-optic modulators using polarization reversal have remarkable features of spatial modulation suitable especially for microwave modulation. This paper reviews electro-optic devices with polarization reversal. An electro-optic modulator with periodic polarization reversal is an efficient phase modulator in microwave frequency regions with quasi-velocity-matching, which is useful not only in modulators but also spectral comb generators and coherence controllers. An electro-optic deflector with slant polarization reversal in a beam diameter is a typical application. Novel electro-optic devices are possible with this technique.抄録全体を表示PDF形式でダウンロード (363K) -
芦原 聡, 志村 努, 黒田 和男2004 年 32 巻 3 号 p. 170-174
発行日: 2004年
公開日: 2008/01/21
ジャーナル フリーCascaded processes of energy exchanges between optical beams via second-order nonlinearities lead to various phenomena, including Kerr-like nonlinear phase shifts and optical solitons. The cascading nonlinearity, combined with the developments in quasi-phase-matching devices, is becoming more promising for all-optical signal processing and ultrashort pulse generation. Here we review the basic properties of the cascading nonlinearity and present our recent experiments on femtosecond cascading with quasi-phase-matching devices.抄録全体を表示PDF形式でダウンロード (364K) -
皆方 誠2004 年 32 巻 3 号 p. 175-180
発行日: 2004年
公開日: 2008/01/21
ジャーナル フリーThe ferroelectric large capacity memory that made direction of the spontaneous polarization of domain inversion correspond to binary values of a memory can be considered as one of the new devices adapting domain inversion technology. This paper describes the feature of LiNbO3 (LN) and LiTaO3 (LT) crystals investigated mainly for the purpose of memory application, the mechanism of domain inversion control, and its applicability in large capacity memory. LT crystal is considered to be a suitable material for nm-size polarization control memory, and this paper describes that the electron beam polarization controlling method is one of the methods effective for nm-size polarization control. Specifically, if thin LT crystal layer with a thickness of 1 μm can be formed, very small polarization structure with a diameter of less than 3 nm could be realizable. If polarization control of 1 dot is carried out into 10 nm × 10 nm region, a super-large capacity memory with a density of 1 T bit/cm2 may be realized.抄録全体を表示PDF形式でダウンロード (1050K) -
栗村 直, 北村 健二2004 年 32 巻 3 号 p. 181-185
発行日: 2004年
公開日: 2008/01/21
ジャーナル フリーA polarization-reversed optical device has been attracting much attention as a next generation device due to its desinability and flexibility. Quasi-phase-matched (QPM) wavelength converters using polarization-reversed structures are reviewed with the focus on materials' progress. We here introduce a low-coercive-field material, stoichiometric LiTaO3, suitable for large aperture QPM devices, and apply it to optical parametric oscillation (OPO). Polarization reversal in electric-field poling is characterized and 35 mm-long QPM OPO devices are demonstrated, while wafer quality is improved. The slope efficiency and the tuning range are reported in wavelength conversion to midinfrared region.抄録全体を表示PDF形式でダウンロード (677K)
レーザーオリジナル
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村田 博司, 岡村 康行2004 年 32 巻 3 号 p. 186-190
発行日: 2004年
公開日: 2008/01/21
ジャーナル フリーNovel guided-wave electro-optic (EO) single side-band (SSB) modulators by using periodically polarization-reversed structures are proposed and demonstrated. Adopting the polarization-reversal schemes to the guided-wave EO modulators, it is possible to have quasi-velocity-matching and control the magnitude and the phase of EO modulation, which leads to realize high-speed SSB modulators with simple optical waveguide and modulation electrode structures. In this paper, their basic structures, operation principles, and experimental demonstrations are presented.抄録全体を表示PDF形式でダウンロード (308K) -
森川 顕洋, 杉田 知也, 水内 公典, 山本 和久2004 年 32 巻 3 号 p. 191-196
発行日: 2004年
公開日: 2008/01/21
ジャーナル フリーWe propose a novel method for controlling the shape of a short period domain-inverted structure utilizing a multi-pulse poling method. Using this technique, periodically domain-inverted structures with periods of 1.4-2.4 μm were fabricated for over 10 mm interaction length in 2 mm thick Z-cut MgO: LiNbO3 crystal. We have demonstrated highly efficient ultraviolet light generation (340-390 nm) using bulk QPM-SHG devices with these structures. Continuous wave 72 mW at wavelength of 372 nm was generated with conversion efficiency of 17 %.抄録全体を表示PDF形式でダウンロード (538K)
レーザーオリジナル
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谷山 哲哉, 庄司 貴彦2004 年 32 巻 3 号 p. 197-202
発行日: 2004年
公開日: 2008/01/21
ジャーナル フリーThis paper describes a method of obtaining the thermal diffusivity of a metal sample of known thickness. By irradiating an intensity-modulated laser beam of 8 W to the sample at power density of 1.5 × 108 W/m2, thermoelastic waves thus produced are detected with a PZT film attached to the back face of the sample. The thermal diffusivity can be obtained by using modulation frequency characteristics of phase contrast of the detected thermoelastic waves. A relation f0 =1.3 λl-2 is confirmed experimentally, where f0 denotes modulation frequency, l metal thickness and λ thermal diffusivity. This relation coincides well with the calculated result obtained on the basis of the theory developed by Jackson and Amer. We hope a measuring apparatus to the thermal diffusivity of a metal plate with thickness of 1.0 × 10-4 m ∼ 2.0 × 10-4 m becomes available for a practical use because of its simple structure as well as easy operation.抄録全体を表示PDF形式でダウンロード (681K) -
櫻田 典世, 石井 良夫, 久保田 譲, 渡辺 一弘2004 年 32 巻 3 号 p. 203-207
発行日: 2004年
公開日: 2008/01/21
ジャーナル フリーA laser plastic coloring (LPC) method has been newly developed as an innovative coloring method for plastic materials using a CO2 laser system. Irradiating laser beam to water diluted dye, the dye solution is heated and a material can be dyed at a laser exposed local area. A laser color marking, a multi-color pallet, and image expression have been attempted by using this LPC method. Four colors of cyan, magenta, yellow, and black (CMYK) logos and characters have been colorfully printed on a plastics bulk material using a laser color marking based on LPC method. A multi-color pallet which consist of 18 steps of hues and 8 tones of brightness expressions have been also created by using LPC dot coloring. From digital image which includes color information, a 30 × 30 pixel colorful image has been successfully displayed with a pointillism taste.抄録全体を表示PDF形式でダウンロード (1122K) -
Shinobu OHARA, Jun-ichi SATO, Masamori ENDO, Shigeru YAMAGUCHI, Kenzo ...2004 年 32 巻 3 号 p. 208-210
発行日: 2004年
公開日: 2008/01/21
ジャーナル フリーA Raman spectroscopy-based gas sensor employing a high-finesse simple diode laser pumped external cavity, Power Build-up Cavity (PBC), has been developed. Results show that a compact 10-cm-long PBC includes a simple diode-laser-pumped external cavity could achieve an intra-cavity power of 40 W with a photon lifetime of up to 29 μs. Raman scattering light from trace methane in the PBC was detected by a photo multiplier tube and a bandpass filter. Good linearity of the detected Raman signal was obtained in the 90-500 ppm methane concentration region with a response time of 1 sec.抄録全体を表示PDF形式でダウンロード (82K)
Technical Note
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Dazhi LI, Kazuo IMASAKI, Shuji MIYAMOTO, Shou AMANO, Takayasu MOCHIZUK ...2004 年 32 巻 3 号 p. 211-213
発行日: 2004年
公開日: 2008/01/21
ジャーナル フリーLaser Compton Scattering gamma ray has been produced via a Nd:YAG laser head-on colliding the high energy electron beam of NewSUBARU storage ring by maximum energy of 17.6 MeV and flux of 1.75 × 104 counts/sec. The gamma ray can be yielded in linear polarization or circular polarization corresponding to the incoming laser light, respectively, and as is known, its spatial distribution relates to the polarization. In this paper, we report the measurement of spatial distribution of laser Compton scattering gamma ray through imaging its spot by an imaging plate. The experimental results coincide with the theoretical predictions.抄録全体を表示PDF形式でダウンロード (705K)
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