The Review of Laser Engineering
Online ISSN : 1349-6603
Print ISSN : 0387-0200
ISSN-L : 0387-0200
Volume 40 , Issue 5
Topical Papers on Latest Frontiers of Research on Low-Energy Optical Signal Processing -from Device to System-
Showing 1-8 articles out of 8 articles from the selected issue
Topical Papers on Latest Frontiers of Research on Low-Energy Optical Signal Processing -from Device to System-
Topical Paper
Laser Review
  • Ken-ichi KITAYAMA
    2012 Volume 40 Issue 5 Pages 332-
    Published: 2012
    Released: July 16, 2020
    JOURNALS FREE ACCESS
    This reviews the current status and its prediction in 2020 of power consumption of ICT, followed the two methodologies of analysis of power consumption of optical network and optical transport; top-down and bottom-up approaches. Next, technologies for the power saving in optical network and optical transport will be discussed. Finally, some of promising optical signal processings in the future are reviewed, and the advantages over the electronic counterpart are discussed.
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  • Shigeru NAKAMURA
    2012 Volume 40 Issue 5 Pages 338-
    Published: 2012
    Released: July 16, 2020
    JOURNALS FREE ACCESS
    Developing ultra-small optical devices and integrating them are quite useful for realizing energy effi cient optical devices and also constructing ICT systems with newly introducing such optical devices. For this purpose, silicon photonics is quite promising. In this report, we briefl y review recent silicon photonics technology trends and then focus on optical switching devices based on silicon photonics. A silicon thermo-optical switch element is driven with low heating power. To integrate many elements and construct functional devices with energy effi ciency, we need to establish several points, such as high uniformity, polarization independence, and ambient temperature independence. We demonstrate high extinction ratio switching of the 1 × 8 optical switch with meeting above-mentioned points for energy efficiency. Such optical switches can be applied to R-OADMs in photonic networks, which provide fl exible optical path setup and thus contribute to energy effi cient systems.
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  • Takuo TANEMURA, Yoshiaki NAKANO
    2012 Volume 40 Issue 5 Pages 344-
    Published: 2012
    Released: July 16, 2020
    JOURNALS FREE ACCESS
    With the continuous growth of data traffi c in the communication networks and datacenters, the energy consumption at the electric packet switches and routers is becoming the bottleneck in scaling up the data capacity. Optical switching has been considered as the key technology to achieve drastic energy saving by bypassing the power-consuming electric packet forwarding. In this article, we review the present status of the high-speed, large-scale photonic integrated switches using InP-based compound semiconductor materials. Recent trends and progresses in the wavelength-converting switches and semiconductor optical amplifi er switches are presented. We then review our work on integrated phasedarray switches and discuss their potentials as well as challenges.
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  • Naoaki YAMANAKA, Kazumasa TOKUHASHI, Hidetoshi TAKESHITA
    2012 Volume 40 Issue 5 Pages 351-
    Published: 2012
    Released: July 16, 2020
    JOURNALS FREE ACCESS
    The power consumption of network devices will continue to increase due to the increase in transmission speed and reach 97 GW by 2020. This paper introduces urgently needed network power reduction methods. First, the paper focuses on the optical access network architectures that use active devices such as high-speed optical switches or variable wavelength lasers to achieve significant energy savings. These new architectures are expected to dramatically reduce the Optical Network Unit (ONU)’s power consumption by introducing an effective sleep mode. Second, this paper introduces an extremely energy efficient future-Internet architecture that uses a large optical aggregation network. It combines the centralized Service Cloud with the Cloud Router and application servers and the Optical Aggregation Network. The optical aggregation network can be realized with just simple optical circuit switches, wavelength-converters, and wavelength-multiplexers/demultiplexers; the complicated layer-3 function is realized only at the center Cloud Router. The optical aggregation network realizes a network structure well suited to today’s traffic centralization. According to our evaluation, total network power consumption can be reduced to just 1/1000 compare to the electrical based network architecture.
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  • Shu NAMIKI
    2012 Volume 40 Issue 5 Pages 356-
    Published: 2012
    Released: July 16, 2020
    JOURNALS FREE ACCESS
    This article will review dynamic optical path network (DOPN), recently proposed by AIST, that is a promising technology to dramatically reduce the energy consumption allowing the sustainable growth of the network traffic in the forthcoming ultra-high definition video era. Then, some of the enabling photonic technologies being developed at AIST will be introduced: they are intersubband quantum well waveguide devices; silicon photonics optical switches; and all-optical signal processing through highly nonlinear fiber.
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  • Masaya NOTOMI, Kengo NOZAKI, Akihiko SHINYA, Shinji MATSUO
    2012 Volume 40 Issue 5 Pages 363-
    Published: 2012
    Released: July 16, 2020
    JOURNALS FREE ACCESS
    Photonic crystal nanocavities have enabled ultrasmall and largely-integratable optical memories and random access memories (RAMs) that consume extremely little power. Here we show the characteristics of our photonic crystal memories and RAM, and discuss their impact on information and communication technology (ICT) and chip-scale many-core processors, especially for network routing functions.
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  • Hitoshi KAWAGUCHI
    2012 Volume 40 Issue 5 Pages 369-
    Published: 2012
    Released: July 16, 2020
    JOURNALS FREE ACCESS
    This paper overviews the current status of bistable semiconductor lasers and their applications to photonic switching as well as the recent results of our research on polarization bistable VCSELs. Many kinds of bistable semiconductor lasers such as VCSELs and ring-lasers with low power consumption have been developed so far. In our experiments with 980-nm polarization-bistable VCSELs, we successfully demonstrated the following results. All-optical fl ip-fl op operation was achieved at a record low bias current of 0.85 mA using an oxidation confi nement structure. 1-bit data signals were arbitrarily sampled and memorized from 20 Gb/s PRBS RZ and 40 Gb/s NRZ signals.
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Laser Original
  • Takasumi TANABE, Hisashi SUMIKURA, Eiichi KURAMOCHI, Hideaki TANIYAMA, ...
    2012 Volume 40 Issue 5 Pages 375-
    Published: 2012
    Released: July 16, 2020
    JOURNALS FREE ACCESS
    We demonstrate photo-detection at 1.55-μm wavelength light using a photonic crystal nanocavity with an integrated p-i-n junction. The device is made from silicon and integrated on a chip. Our results showed that it has an extremely low dark current of 15 pA and can operate at high sensitivity. The detectable smallest input light was 0.9 nW, which outperformed other detectors such as a germanium detector on silicon due to the strong confi nement of the light by ultrahigh-Q photonic crystal nanocavity. We also performed detailed theoretical and numerical analysis and showed that quantum effi ciency of 12.5% is possible using two-photon absorption. Higher effi ciency is possible if we can increase the onephoton absorption or the cavity’s Q. Based on our analysis, the sensitivity can be reduced to 1.8 pW due to the low dark current.
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