Abstract
Microcombs provide a potential compact and efficient light source for
multi-Terabit-per-second optical superchannels. However, as the
bandwidth of these multi-wavelength light sources is increased, this can
result in low per-line power. Optical amplifiers can be used to overcome
power limitations, but the accompanying spontaneous optical noise can
degrade performance in optical systems. To overcome this issue, we
propose wideband noise reduction for comb lines using a high-Q microring
resonator, whose resonances align with comb lines. When applying the
proposed distillation to a superchannel system with 18 Gbaud, 64-QAM
sub-channels in a > 10 Tb/s optical superchannel, we find
that noise-corrupted comb lines can reduce the optical signal-to-noise
ratio required for the comb by ~ 9 dB when used as
optical carriers at the transmitter side, and by ~ 12 dB
when used as a local oscillator at the receiver side.