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Volume 24, Issue 7
Displaying 1-12 of 12 articles from this issue
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Hiroshi MASUHARA1996 Volume 24 Issue 7 Pages 743
Published: July 25, 1996
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSDownload PDF (134K) -
Keiji SASAKI1996 Volume 24 Issue 7 Pages 744-749
Published: July 25, 1996
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSA new microprobe of a near field scanning optical microscope has been developed for elucidating chemical reaction processes occurring in nanometer volumes. The probe is composed of a lasing microsphere, that induces the high-intensity localized optical field just outside of the sphere, and of a nanometer-sized particle fixed on the surface. Photon tunneling through the nanoparticle can be observed with high sensitivity due to the intracavity effect. Three-dimensional positioning control of the microprobe is performed by a laser manipulation technique based on radiation pressure.View full abstractDownload PDF (866K) -
Hiroaki MISAWA1996 Volume 24 Issue 7 Pages 750-756
Published: July 25, 1996
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSLaser manipulation-microfabrication system consisting of a CW laser, a picosecond pulsed laser and an optical microscope was developed to assemble micrometer-sized structure in solution. Photopolymerization of reactive monomers induced at the focal spot of picosecond laser pulses (λ = 355 nm or 532 nm, FWHM = 30 ps, repetation rate = 10 Hz) was employed for connection of glass particles regularly aligned by laser trapping. Since photopolymerization was induced in the vicinity of a focal spot, any desired numbers of glass particles with arbitrary geometrical structure can be connected by repeating the manipulation and the photopolymerization procedures.View full abstractDownload PDF (2540K) -
Naoto TAMAI1996 Volume 24 Issue 7 Pages 757-764
Published: July 25, 1996
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSTotal internal reflection phenomena in the interface layers of solid/aqueous polymer solution and solid/liquid crystals were used as laser induced optical switching. Phase transition of a polymer in the interface layers induced by the evanescent wave of IR laser was demonstrated for the optical switching as a new class of microchemistry. Possibilities and limitations of optical switching spectroscopy in the interface layers were also discussed.View full abstractDownload PDF (1100K) -
Masahide TERAZIMA1996 Volume 24 Issue 7 Pages 765-772
Published: July 25, 1996
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSPhotothermal techniques, which can detect heating processes induced by the energy from a photoexcited material with a high sensitivity and a high time resolution open a new field in chemistry, biology, and technology. Principles for detection and vaious unique applications are reviewed and discussed. Recent development of a new photothermal signal component allows us to study very initial processes of the heating.View full abstractDownload PDF (1077K) -
Hiroshi FUKUMURA1996 Volume 24 Issue 7 Pages 773-779
Published: July 25, 1996
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSA new method to transfer aromatic molecules between two contacting polymer films by nanosecond pulse laser irradiation is outlined. The mechanism of the laser-induced mass transfer is discussed in connection with laser-induced super heated states of polymer solid. Temperature dependencies of molecular and thermal diffusion processes in polymer solid are considered to be important factor.View full abstractDownload PDF (969K) -
Shunichi KAWANISHI, Nobuyuki CHINOSE1996 Volume 24 Issue 7 Pages 780-786
Published: July 25, 1996
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSExcimer laser-induced photochemical reactions were applied to the surface modification of fluoropolymers. Irradiation of excimer laser pulses onto fluoropolymer films in contact with various solutions of reactants provided the surface with chemical functionalities of chemical affinity to water, solvents, and adhesives. The reactions proceed through electron transfer from excited states of the reactants, produced in high concentrations by the intense laser irradiation, to the polymer surfaces.View full abstractDownload PDF (1033K) -
Nobuaki NAKASHIMA1996 Volume 24 Issue 7 Pages 787-795
Published: July 25, 1996
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSTwo topics of photochemistry and emission processes of lanthanide ions in solutionare described. Two-step-excitation can be a method of activation of Eu3+ ion in solution. Excitation with a sub-picosecond pulse was found to result in highly efficient photoreductionof Eu3+ion in solution: Eu3+ + 2hv → Eu2+. Laser photo-redox-reactions of metal ions will be hopefully applied for nuclear fuel reprocessing and partitioning of nuclear high-level waste. Nd3+ [CF3COCDCOCF3] 3 and related complexes have been found to be luminescent in organic solvents. Ligands with low frequencies successfully depressed nonradiative transitions. The possibilities of laser emission are discussed. Lanthanide ions in organic solvent could be candidates for a highly repetitive laser with high power for laser fusion.View full abstractDownload PDF (1256K) -
Tsuyoshi ASAHI, Hiroshi MASUHARA1996 Volume 24 Issue 7 Pages 796-803
Published: July 25, 1996
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSA recent development of ultrafast laser spectroscopy for highly light sattering materials is presented. Utilizing a stable femtosecond Ti: sapphier laser system has made it possible to get information about the dynamics of short-lived transient species in powder materials such as polymer latex perticles and organic microcrystals with a few ps temporal resolution. Time-resolved measurements of a diffuse reflected pulse with high temporal resolution are another important application of femtosecond laser technique. Its potential application toimaging and space- and time-resolved spectroscopy of the materials are described.View full abstractDownload PDF (1254K) -
Hiroshi MIYASAKA, Takao MORIYAMA, Akira ITAYA1996 Volume 24 Issue 7 Pages 804-812
Published: July 25, 1996
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSPrinciples and utilities of picosecond transient dichroism and birefringence measurements were reviewed. It was introduced that the measurements of transient birefringence easily provided the time correlation function of the picosecond laser pulse and the dispersion of the picosecond white light continuum. The application of the dichroism measurement to the direct investigation on the primary processes of photoconduction in poly (N-vinylcarbazole) clearly demonstrated that the hole migration from the cation state of carbazole moiety (Cz) to neighboring Cz's in solid films took place in nanosecond time regions . From this direct measurement, the mechanism of the primary processes of photoconduction was established. In solution phase, the dichroism measurements of photoinduced electron transfer processes in poly (N-vinylcarbazole) - electron acceptor systems directly revealed the hole migration along a polymer chain as well as the microbrownian motion of the polymer.View full abstractDownload PDF (1129K) -
-Generation of Ultimately-Short Optical Pulse and Its Application-Totaro IMASAKA1996 Volume 24 Issue 7 Pages 813-821
Published: July 25, 1996
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSLaser pulses as short as 6 fs were generted in 1987, but there has been no breakthrough since. This is due to a group velocity dispersion occurred in solid and liquid laser materials and optics used. In this report, I propose a new aproach to generate a shorter optical pulse based on the two-color stimulated Raman effect using a simple optical system. This is based on generation of many rotational lines simultaneously by four-wave Raman mixing. I also discuss itspotential application in physics, chemistry, and technology as well.View full abstractDownload PDF (1454K) -
Noboru KITAMURA, Kiyoharu NAKATANI1996 Volume 24 Issue 7 Pages 822-829
Published: July 25, 1996
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSA laser manipulation technique, combined with microspectroscopic and microelectrochemical methods, has been applied to elucidate mechanistic features of chemical reactions across a single microdroplet/water interface. A potential means of the laser-manipulated method has been demonstrated for direct observations and analyses of interfacial mass transfer andelectron transfer processes of individual microdroplets.View full abstractDownload PDF (1075K)
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