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Volume 25, Issue 8
Displaying 1-12 of 12 articles from this issue
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Michiharu NAKAMURA1997 Volume 25 Issue 8 Pages 545
Published: August 15, 1997
Released on J-STAGE: February 26, 2010
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Takashi EGAWA1997 Volume 25 Issue 8 Pages 546
Published: August 15, 1997
Released on J-STAGE: February 26, 2010
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Masaaki YURI, Osamu IMAFUJI, Toru TAKAYAMA1997 Volume 25 Issue 8 Pages 547-552
Published: August 15, 1997
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSReal refractive index guided self-aligned (RISA) AlGaAs laser diodes have various advantages over conventional complex refractive index guided lasers, which include low operating current, stablefundamental transverse-mode operation up to high power levels, good controllability of current and optica distributions, and so on. In this review, the concept of RISA lasers and their applications to optical data storage systems are presented. Taking advantage of low operating current characteristics of the RISA lasers, a number of optical elements which compose a conventional optical pickup are successfully integrated into a very small plastic package, which results in substantial reduction of pickup size in various optical disk systems.View full abstractDownload PDF (1280K) -
Hideto ADACHI, Masaya MANNOH, Akira TAKAMORI1997 Volume 25 Issue 8 Pages 553-556
Published: August 15, 1997
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSSelf-sustained-pulsing A1GaInP laser diodes having very low intensity noise characteristics were successfully demonstrated by adopting a novel structure, which has highly doped saturable absorbing layer. Short carrier lifetime, which is indispensable for self-sustained pulsation, was realized by applying highly doped saturable absorbing layer. Self-pulsing laser diodes with the lasing wavelength of 650nm-band were fabricated, resulting in the threshold current of 76mA at 20°C. The relative intensity noise (RIN) was below - 138dB/Hz in the temperature range 20-60°C at the average output power of 5mW.View full abstractDownload PDF (769K) -
Gen-ichi HATAKOSHI1997 Volume 25 Issue 8 Pages 557-561
Published: August 15, 1997
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSDevelopment of short-wavelength semiconductor lasers had made a large contribution to the realization of high density optical memories. For example, InGaAlP red lasers have been used as light sources for high capacity optical disc systems (DVD). The next-generation, high definition DVDs will require a furthershortning of laser oscillation wavelength into the blue-light region. This paper reviews recent developments in short-wavelength semiconductor lasers and describes some of the device characteristics related to the optical memory applications.View full abstractDownload PDF (1162K) -
Motoyasu TERAO1997 Volume 25 Issue 8 Pages 562-565
Published: August 15, 1997
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSDVD-RAM is a rewritable DVD disk which has a capacity of 5.2GB. DVD-RAM disk can be recorded an MPEG2 compressed digital movie that is 2.5 hours in length, and is planned to be readable in DVD-ROM drive. DVD-RAM drive can also read CD-ROM disk and DVD-ROM disk.View full abstractDownload PDF (942K) -
Akihiro SHIMA1997 Volume 25 Issue 8 Pages 566-570
Published: August 15, 1997
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSA high-power laser diode (>30mW) emitting at around 650nm is indispensable for a DVD-RAM system. Moreover, high-temperature operation (>-60°C) and high reliability are strongly required. In order to satisfy these requirements, optimization of active layer structure and development of a mirror hardening technology such as a window-mirror are introduced. In addition, some excellent laser performances that it suffers no optical damage up to 150mW and exhibits reliable 30-50mW operation at high-temperatures are presented.View full abstractDownload PDF (971K) -
Yoshitoshi NODA, Katsutoshi TANINO, Shunsuke SUETSUGU1997 Volume 25 Issue 8 Pages 571-574
Published: August 15, 1997
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSNumerical value of the absorption cross-section ao of ruby R1-line has not been established. Here we propose the value of ao measured by a newly developed laser ray method. The method consists of two preparatory experiments, one the evaluation of absorption coefficient ao and the other the determination of chromium concentration No. Process of determining No is performed by utilizing a nonlinear absorbing characteristics of high power laser. Theory and experiment of the process are shown in detail, and finally get the value (Yo = ao /No for a certain rod, and compare it with previous reports.View full abstractDownload PDF (543K) -
Hiroshi TSUBAKIHARA, Hiroyuki MURAKAMI, Kazumichi YOKOYAMA, Toyohiko A ...1997 Volume 25 Issue 8 Pages 575-579
Published: August 15, 1997
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSBeing irradiatd by a KrF laser, the electrical conductivity of polyimides (BPDA/p-PDA, BPDA/DDE, PMDA/ DDE, PMDA/BAPB) is increased permanently. At lower total laser fluences than about 50mJ/cm2, capacitive conductance can be obtained. Irradiated surfaces were firstly structured by powdery falling-back products, and then the formation of flakes was observed at the irradiated area. In this range, both nitrogen and oxygen contents were decreased with increasing total fluences. In the range of total fluences higher than 50mJ/cm2, the laser-induced conductivity consists from D.C. conductive low frequency region and capacitive high frequency region. The energetic laser shots sputtered and/or melted these flakes and formed electrically conducting rough surfaces remaining after ablation. Unusual compositional changes were observed at about 54mJ/cm2. For higher fluences, carbon-rich surfaces with a unified bonding environment (aromatic rings, carbon clusters and etc.) are found to be produced.View full abstractDownload PDF (1003K) -
Nobuhiro UMEMURA, Kunio YOSHIDA, Kiyoshi KATO1997 Volume 25 Issue 8 Pages 580-583
Published: August 15, 1997
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSRbTiOAsO4 (RTA) has been found to be phase matchable for type-2 second-harmonic generation (SHG) from 0.5725 to 1.80μm at 20.0°C. By comparing these experimental results and the published 90°phase-matched parametric oscillator (OPO) tuning points given by Reid et al. and Scheidt et al. with two differentSellmeier's equations of Cheng et al. and Fenimore et al., the latter was found to reproduce well the experimental points of Scheidt et al. as well as our data points. In addition, the absolute values of the nonlinear optical constants of this crystal are discussed.View full abstractDownload PDF (536K) -
Tetsuya TANIYAMA1997 Volume 25 Issue 8 Pages 584-587
Published: August 15, 1997
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe aim of the present author is to study mechanisms of photo acoustic signal generation in water solution of dye for laser. The photo acoustic signal is generated by photon, produced during thermal energy dissipation. Since the excitation by laser does not result in significant quantities of intersystem crossing, the thermal energy produced in the water solution can be evaluated of either fluorescent radiation or non radiative transition. In the present work, quantum efficiency of fluorescent dye by N2 laser is measured and the thermal energy for the source of photo acoustic signal is evaluated.View full abstractDownload PDF (574K) -
Hiroyuki DAIDO, Fujio SHIMIZU, Hideyuki OHTAKE, Nobuhiko SARUKURA, Mas ...1997 Volume 25 Issue 8 Pages 588-607
Published: August 15, 1997
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSDownload PDF (4644K)
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