Wilkinson power dividers (WPDs) are a popular element
in RF and
microwave technologies known for providing isolation capabilities.
However, the benefits that WPDs could offer to integrated photonic
systems are far less studied. Here, we investigate the thermal emission
from and the noise performance of silicon-on-insulator (SOI) WPDs.
We find that WPDs exhibit a noiseless port, with important implications
for receiving systems and absorption-based quantum state transformations.
At the same time, the thermal signals exiting noisy ports exhibit
nontrivial correlations, opening the possibility for noise cancellation.
We analyze passive and active networks containing WPDs showing how
such nontrivial correlations can prevent the amplification of the
thermal noise introduced by WPDs while benefiting from their isolation
capabilities. Using this insight, we propose a modified ring-resonator
amplifier that improves byNtimes the SNR in comparison
with conventional traveling wave and ring-resonator amplifiers, withNbeing the number of inputs/outputs of the WPD. We believe
that our results represent an important step forward in the implementation
of SOI-WPDs and their integration in complex photonic networks, particularly
for mid-IR and quantum photonics applications.