  We show that subwavelength silicon-rich nitride waveguides efficiently
sustain high-speed transmissions at 2 $\mu$m. We report the transmission of a
10 Gbit/s signal over 3.5 cm with negligible power penalty. Parametric
conversion in the pulsed pump regime is also demonstrated using the same
waveguide structure with an efficiency as high as -18 dB.
