Abstract
We present an architecture for wavelength-division-multiplexed coherent data center links employing resonator-enhanced electro-optic frequency comb generators as both transmitter and local oscillator (LO) sources. We show that in each frequency comb, the phase noise in all comb lines is determined completely by the optical phase noise of the seed laser and the phase noise of the microwave oscillator. We propose an analog coherent receiver that performs carrier recovery on all wavelength channels using only two phase-locked loops. We use an independent cascade of phase shifters driven by marker tone detection in each channel for polarization recovery and compensation of a static optical phase shift. We study design examples for quadrature phase-shift keying and 16-ary quadrature amplitude modulation (16-QAM), determining requirements on the transmitter and LO seed laser linewidths and the LO frequency modulation (FM) response. We find that for a dual-polarization (DP) 16-QAM link with 17 wavelength channels, each operating at 56 GBaud, if the combined linewidth of the transmitter and LO seed lasers is 100 kHz, the LO seed laser requires an FM response that is flat from d.c. to several hundred MHz to maintain a phase-error penalty below 1 dB.
PDF Article
More Like This
Kramers–Kronig detection of four 20 Gbaud 16-QAM channels using Kerr combs for a shared phase estimation
Kaiheng Zou, Peicheng Liao, Yinwen Cao, Arne Kordts, Ahmed Almaiman, Maxim Karpov, Martin Hubert Peter Pfeiffer, Fatemeh Alishahi, Ahmad Fallahpour, Moshe Tur, Tobias J. Kippenberg, and Alan E. Willner
Opt. Lett. 45(7) 1794-1797 (2020)
Cited By
You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
Contact your librarian or system administrator
or
Login to access Optica Member Subscription