  In this paper, we experimentally validate our previous numerical works in
recurrent optical spectrum slicing (ROSS) accelerators for dispersion
compensation in high-speed IM/DD links. For this, we utilize recurrent filters
implemented both through a waveshaper and by exploiting novel integrated
programmable photonic platforms. Different recurrent configurations are tested.
The ROSS accelerators exploit frequency processing through recurrent optical
filter nodes in order to mitigate the power fading effect, which hinders the
transmission distance and baudrate scalability of IM/DD systems. By equalizing
even 80 km of 64 Gb/s PAM-4 transmission in C-band, we prove that our system
can offer an appealing solution in highly dispersive channels.
