By Bruno Cimoli
The growth of annual IP-traffic has generated a demand for 400G optical links. Traditionally, datacenter links employ on-off keying (OOK) modulation, which is spectrally inefficient. This project investigates novel 400G optical solutions, adopting polybinary modulation, which apart from increasing spectral efficiency also reduces optical transmissions impairments chromatic dispersion and Brillouin backscattering.
Data transmission experiments using polybinary have demonstrated that the design of the low pass filter (LPF) required for the modulation is critical. Also the bit-rate of datacenter links changes according to IP-traffic demands; thus an optimal solution has to be reconfigurable.
Given this scenario the main problem that this PhD project tackles is the design of a reconfigurable microwave LPF for the generation of polybinary signals for 400G optical solutions.
The final result will be the development of a tunable microwave LPF able to preserve a specific linear phase characteristic when reconfigured.
Completed: 2019