A Subcarrier-Multiplexed Coherent FSK System Using a Mach-Zehnder Modulator with Automatic Bias Control

Q. Jiang, M. Kavehrad

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    10 Scopus citations


    We demonstrate a subcarrier-multiplexed coherent optical transmission system using a push-pull Mach-Zehnder intensity modulator. Six subcarrier channels cover a six-octave bandwidth and are frequency-shift keying (FSK) modulated at 45 Mb/s. With an optical phase modulation index of 0.38, a receiver sensitivity of - 36 dBm is obtained. Second-order intermodulation is canceled by more than 20 dB due to the balanced structure of the modulator. This results in an 8-dB improvement in the receiver sensitivity compared to the system using an optical phase modulator. We also demonstrate a simple automatic bias-control scheme for the Mach-Zehnder modulator. It utilizes the optical signal from the complementary output port of the dual-output modulator.

    Original languageEnglish (US)
    Pages (from-to)941-943
    Number of pages3
    JournalIEEE Photonics Technology Letters
    Issue number8
    Publication statusPublished - Aug 1993


    All Science Journal Classification (ASJC) codes

    • Electronic, Optical and Magnetic Materials
    • Atomic and Molecular Physics, and Optics
    • Electrical and Electronic Engineering

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