Broadband optical fibre amplification over 17.7 THz range

A lumped optical fiber amplifier exploiting the full spectrum of optical fibers and delivering a record bandwidth of 17.7 THz was achieved using a combination of erbium-doped, thulium-doped and Raman fibers. The bandwidth can be directly used in wavelength division multiplexing systems since a gain equalization of only 6 dB would be required to flatten the gain spectrum, and only commercially available components were used in the amplifier.