  Continued cost- and power-efficient capacity scaling in optical networks is
imperative to keep pace with ever-increasing traffic demands. In this paper, we
investigate multi-wavelength transponders as a potential way forward. Suitable
system architectures and realistic specifications of multi-wavelength
transponders are identified and analyzed in terms of transmit OSNR penalties
and spectral constraints. We investigate the performance for different
specifications as compared to single-wavelength transponders in a network
planning study on two network topologies, developing guidelines for
multi-wavelength transponders specifications and their potential benefits. The
studies show a reduction in the number of required lasers of up to 83% at the
expense of a slight increase in number of lightpaths, demonstrating the
potential for significant cost savings and efficiency improvements.
