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Volume 35, Issue 9
Displaying 1-10 of 10 articles from this issue
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Tadamasa KIMURA2007 Volume 35 Issue 9 Pages 548-549
Published: September 15, 2007
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSDownload PDF (266K) -
Koji YAMADA, Tai TSUCHIZAWA, Toshifumi WATANABE, Hiroshi FUKUDA, Hiroy ...2007 Volume 35 Issue 9 Pages 550-555
Published: September 15, 2007
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSSilicon photonic wire waveguide, whose core size is as ultra-small as around 500-nm, is fabricated by using the technologies developed in semiconductor industry. For example, electron-beam or deep-ultraviolet lithography and dry etching using low-pressure plasmas are applied in the fabrication. In the practical application of these technologies, however, we must solve technical difficulties in geometrical error and surface roughness in nanometer level. In this paper, we discuss fabrication technologies that satisfy these severe fabrication accuracies. We also show some practical applications of silicon photonic wire waveguides, and confirm the present standard of their fabrication technologies.View full abstractDownload PDF (16861K) -
Toshihiko BABA, Kosuke SASAKI, Daisuke MORI2007 Volume 35 Issue 9 Pages 556-560
Published: September 15, 2007
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSThis paper presents two types of Si-based optical waveguides; one confines light by the total internal reflection and the other by the Bragg reflection. The former called photonic wire waveguide allows low loss and wideband light transmission through sharp bends and micro-optic components. Therefore, it is suitable for dense optical wiring in large-scale photonic integrated circuits. By using this waveguide, an arrayed waveguide grating demultiplexer is dramatically miniaturized. The latter called photonic crystal waveguide is unique on this point that it generates slow light having an extremely low group velocity. By controlling operating bandwidth and dispersion, it will be applicable to an optical buffer and high efficiency light control device.View full abstractDownload PDF (11928K) -
Tak-Keung LIANG, Kouichi AKAHANE, Naokatsu YAMAMOTO, Luis Romeu NUNES, ...2007 Volume 35 Issue 9 Pages 561-565
Published: September 15, 2007
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSUltra-fast silicon all optical switches using two-photon absorption (TPA) were developed in silicon nanowire optical waveguide on silicon-on-insulator substrate. This waveguide can produce high optical intensities that yield optical nonlinearity such as TPA even at input optical powers typically used in fiber optic communication systems. In addition, we fabricated a high quality GaSb based quantum well (QW) on a Si substrate using AlSb initiation layer. The emission wavelength of QW was 1.55 μm at room temperature, so that the new function can be developed on Si-photonics using this QW.View full abstractDownload PDF (4558K) -
Hideo ISSHIKI, Tadamasa KIMURA2007 Volume 35 Issue 9 Pages 566-571
Published: September 15, 2007
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSIntegration of silicon light sources on a Si chip is one of milestone to establish new paradigm of LSI systems, so-called “silicon photonics” . In recent years remarkable progress has been made in the Si wire waveguide technologies for optical interconnection on a Si chip. This paper reviews Si-related optical materials and their light emitting devices from a viewpoint of compatibility with Si wire waveguide. An ErSiO superlattice crystal that we have newly developed is introduced as one candidate of the light source material for silicon photonics. To mention the particular features, this material has a superlattice structure with 0.86-nm period and a large amount of Er (-15 %) as its constituent. In addition, the ErSiO superlattice crystal behaves as a semiconductor and the Er 4f-electrons are excitable by electron-hole pairs in the host. These show the possibilities of high optical gain and its electrical control in Er-doped waveguide amplifier (EDWA).View full abstractDownload PDF (4858K) -
Keishi OHASHI2007 Volume 35 Issue 9 Pages 572-576
Published: September 15, 2007
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSThe concept of nano-photodiode, employing surface-plasmon antenna to create sub-wavelength size nearfield, is described in relation to silicon photonics. Response time of the prototype silicon nano-photodiode was much shorter (-20 ps) than that of conventional silicon photodiodes (>1 ns). There are two reasons for the high-speed response: short distance between electrodes (-100 nm) and small electrode area (< 1 μm2). The former is realized by lapping near-field region over depletion region (Schottky barrier) in silicon thereby eliminating time-consuming carrier diffusion process. The latter results in small electrode capacitance and thus reducing response time of the photodiode circuit. This nano-photodiode technology can be applied to other semiconductor materials such as germanium and ternary compound semiconductors.View full abstractDownload PDF (1716K) -
Susumu FUKATSU2007 Volume 35 Issue 9 Pages 577-585
Published: September 15, 2007
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSA new class of band-gap conversion scheme based on proximity effects is described, which allows the otherwise indirect-gap Si to behave more like a neighboring direct-gap semiconductor in terms of radiative transition. Evanescent coupling of the electronic wave function of Si to that of the adjacent direct-gap counterpart in the mid-gap across the interface of staggered band alignment is taken advantage of to exploit the dipoleallowed, momentum-conserving quasi-direct interband recombination. The quasi-direct GaSb-Si quantum dot system created thereby will be reviewed with some of the prominent features being highlighted as represented by near-infrared gain.View full abstractDownload PDF (2065K) -
Kazumi WADA2007 Volume 35 Issue 9 Pages 586-590
Published: September 15, 2007
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSThe present paper reviews recent advances of system applications of on-chip optical interconnections in terms of Si Photonics to overcome “heat penalty” in Si LSIs.View full abstractDownload PDF (1480K) -
Kazunobu KOJIMA, Muneyuki ADACHI, Ken-ichi HAYASHI2007 Volume 35 Issue 9 Pages 591-595
Published: September 15, 2007
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSFor the light source of photocoagulators for ophthalmology, an orange laser is more suitable. We developed two orange fiber lasers (580 nm and 590 nm) to investigate the effectiveness depending on the different wavelengths in the range of orange. The 580 nm laser is composed of a 1160 nm fiber laser and a PPLN crystal for second harmonic generation. Continuous-wave 1.3 W output power of 580 nm was obtained with 5.8 W input power of 1160 nm. The 590 nm laser is almost the same as the 580 nm laser source. In this case we used a Raman shift fiber to generate 1180 nm, and the output power of 590 nm is 1.4 W. We newly developed an evaluation model of the photocoagulator system using these two laser sources. The coagulation output power was 700 mW, which is enough for usual laser photocoagulator systems. This photocoagulator system showed excellent performance in the field evaluation using colored laboratory rabbits.View full abstractDownload PDF (4151K) -
Kanade OGAWA, Yutaka AKAHANE, Tetsuo HARIMOTO, Makoto AOYAMA, Koichi T ...2007 Volume 35 Issue 9 Pages 596-598
Published: September 15, 2007
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSWe demonstrated ultra-broadband optical parametric chirped-pulse amplification using a picosecond diverging pump beam in the 1 μm wavelength region. An amplification bandwidth of more than 400 nm was achieved in a type-I BBO crystal with a gain of 1.2×105.View full abstractDownload PDF (391K)
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