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Volume 33, Issue 8
Displaying 1-7 of 7 articles from this issue
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Shuji SAKABE2005 Volume 33 Issue 8 Pages 512-513
Published: August 15, 2005
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSDownload PDF (317K) -
Masaki HASHIDA, Seiji SHIMIZU, Shuji SAKABE2005 Volume 33 Issue 8 Pages 514-518
Published: August 15, 2005
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSRecently, a periodic nano-structure formation by short pulse laser has been demonstrated for various materials, such as metals, dielectrics, and semiconductors. However, the patterned nano-structure could not be explained by the classical interference model and two temperature thermal model. Short pulse laser-matter interactions have different physics on the ablation mechanism from nanosecond laser ones. Additionally, the nano structure has been used for various kinds of applications, for example, diagnosis of the target composition, removal of small space debris, and surface modification. In this article, features of the short pulse laser ablation are reviewed and some applications are introduced.View full abstractDownload PDF (6249K) -
Naoki YASUMARU, Kenzo MIYAZAKI, Junsuke KIUCHI2005 Volume 33 Issue 8 Pages 519-524
Published: August 15, 2005
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSThis paper reviews our recent observations of fine periodic structures, so-called nanostructures, formed on hard thin films of TiN, CrN and DLC irradiated with femtosecond (fs) laser pulses. The size of nanostructures is much smaller than that of well-known ripple structures characterized by the laser wavelength. The structure size and surface morphology depend on polarization, wavelength, fluence and pulse width of the fs laser, as well as on the target material. The laser irradiation conditions have been studied to control the nanostructure formed on the thin films. Under almost the same conditions as for the nanostrucure formation, we have observed that a surface modification of DLC into glassy carbon is induced with the fs laser pulses.View full abstractDownload PDF (16437K) -
Hiroshi SAWADA2005 Volume 33 Issue 8 Pages 525-529
Published: August 15, 2005
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSSurface periodic structures can be formed on various kinds of materials using linearly polarized femtosecond laser pulses with low fluence that is slightly above the ablation threshold. This paper summarizes novel surface characteristics of femtosecond laser-induced periodic structures. The periodic structures show remarkable effects for example, reducing a material's friction coefficient or improving adhesion between diamond-like carbon (DLC) film and its metal substrate. Furthermore, the periodic structures enhance cellular sensibility. Osteoblasts orient themselves along the lines of periodic structures.View full abstractDownload PDF (10851K) -
Alexandre SEMEROK, Patrick MAUCHIEN2005 Volume 33 Issue 8 Pages 530-536
Published: August 15, 2005
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSLaser microablation processes of solid materials (metals, alloys, dielectrics) were studied for their application to surface elemental analysis. The features of laser plasmas and craters produced by femtosecond and picosecond lasers are presented. The application of laser ablation to surface microanalysis in combination with optical emission spectroscopy (LA-OES) is discussed. The methods to control laser ablation for more efficient elemental analysis and the applications to surface characterisation with submicrometric and nanometric resolutions are proposed.View full abstractDownload PDF (5658K) -
Yasuhiro MORI, Masamoto TAKATSUJI, Junji HARADA2005 Volume 33 Issue 8 Pages 537-541
Published: August 15, 2005
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSWe cultured rose tissues under irradiation of LED and LD at different wavelengths, and examined their effects on the growth and flowering of roses. As a result, flower-bud differentiation was rarely observed under irradiation of red (660 nm) and green (517 nm) LED, but it was enhanced by irradiation of blue (465 nm) and bluegreen (502 nm) LED. In particular, flowering was observed in 76% of the samples irradiated with blue-green LED, which was the highest flowering rate. However, flowering occurred earlier by irradiation of blue LED than by that of blue-green LED, and the flowering position (node position) was lower by the former irradiation than by the latter irradiation. The irradiation of LD (445 nm) demonstrated a higher flowering rate and earlier flowering than the irradiation of LED, but the growth rate was lower by the former irradiation than by the latter irradiation. This may be because there are photoreceptors that absorb blue to blue-green light and induce flower-bud formation. Since the wavelength width of LD is smaller than that of LED, energy for the increase in the growth rate may have been suppressed, and used for the reproductive growth, resulting in the enhancement of flowering.View full abstractDownload PDF (2181K) -
Kazushi YOSHIKAWA, Kanji ZENNYU, Masayoshi INOUE, Junji KATO2005 Volume 33 Issue 8 Pages 542-543
Published: August 15, 2005
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSIn some former reports, the irradiation of laser improved the dentin hypersensitivity in the clinical situations. However, the mechanism of the improvement has not fully been understood. The purpose of this study was to investigate the effects of the laser irradiation on the coagulation of a protein using a liver of Pig. The liver surface was laser-irradiated as a following conditions; Scan speed of the irradiation: 4.7mm/sec, Area of the irradiation: 5×10-3cm2, Output power: 280mW, Power density: 56W/cm2, Repetition rate: 40 Hz, Pulse duration: 650μsec. The photograph images showed that the irradiation of CO2 laser using this condition coagulated the protein without causing thermal damage to the peripheral tissue. Hence, we suggest that the CO2 laser irradiation of this parameter is effective for the treatment of the dentin hypersensitivity in the clinical situations.View full abstractDownload PDF (3536K)
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