High total dose gamma and neutron radiation tolerance of VCSEL assemblies

    Research outputpeer-review

    Abstract

    Optical fiber technology is seriously considered for communication and monitoring applications during the operation and maintenance of future thermonuclear fusion reactors. Their environment is characterized, in particular, by possibly high gamma dose-rates and total doses in excess of 10 MGy. In addition, the maintenance equipment might be stored in close vicinity of the reactor during its operation and therefore the communication devices might also be exposed to a substantial neutron fluence. The feasibility of applying photonic technology in these radiation fields therefore needs to be assessed. Whereas many reports deal with the radiation behavior of a variety of fiber-optic devices, only little information is available on the radiation tolerance at high total dose (e.g. > 1 MGy). We describe our recent results obtained on vertical-cavity surface-emitting laser (VCSEL) assemblies. We have conducted high total dose (up to 20 MGy) irradiation experiments on such devices, which confirmed their excellent gamma radiation hardness. The optical power loss at nominal forward current was less than 2 dB and the threshold current remained unaltered. We have also irradiated these devices with neutrons inside the BR1 reactor (SCK•CEN, Mol, Belgium) up to a total fluence on the order of 1015 n·cm-2. The response of VCSELs to neutrons is, as expected, different from that to gamma radiation. VCSELs previously exposed to gamma rays exhibited an accelerated degradation under neutron radiation compared to not pre-irradiated devices. The beneficial effect of applying a continuous forward bias to the VCSELs is also evidenced.

    Original languageEnglish
    Title of host publicationProceedings of SPIE
    Subtitle of host publication Photonics for Space Environments VIII
    Pages162-171
    Number of pages10
    Volume4823
    DOIs
    StatePublished - Nov 2002
    EventPhotonics for Space Environments VIII, 9-10 July 2002, Seattle, USA - Seattle
    Duration: 7 Jul 200211 Jul 2002

    Publication series

    NameProceedings of SPIE - The International Society for Optical Engineering
    PublisherSPIE - Society of Photo-optical Instrumentation Engineers
    ISSN (Print)0277-786X

    Conference

    ConferencePhotonics for Space Environments VIII, 9-10 July 2002, Seattle, USA
    Country/TerritoryUnited States
    CitySeattle
    Period2002-07-072002-07-11

    ASJC Scopus subject areas

    • Electronic, Optical and Magnetic Materials
    • Condensed Matter Physics
    • Computer Science Applications
    • Applied Mathematics
    • Electrical and Electronic Engineering

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