• Atul Srivastava

    Atul Srivastava is chief technology officer at NTT Electronics Corp. (NEL) America.

    (All figures courtesy of Oclaro and NEL America)
    FIGURE 1. In a hybrid Raman/EDFA system, the high-power 14xx nm Raman pump diodes are combined and launched into the fiber span counter-propagating with respect to the signal. Distributed Raman preamplification provides low noise, and the EDFA section provides high gain and high output-signal power. Flat gain spectra over a wide range of gains are provided by the combination of the four-pump-wavelength Raman pump configuration and the two-stage EDFA with variable optical attenuator and gain-flattening filter between the two stages.
    C- and L-band erbium-doped fiber amplifiers, hybrid Raman/EDFA systems, new gain-medium materials, and semiconductor optical amplifiers continue to extend the reach of wavelength...
    Dec. 1, 2011