Article https://doi.org/10.1038 /s41467-025-6128 8-x
Integrated multi-port multi-wavelength
coherent optical source for beyond Tb/s
optical links
Ali Pirmoradi
1
,JizhaoZang
2,3
, Kaisarbek Omirzakhov
1
, Zhehao Yu
1
,
Yan Jin
2,3
,ScottB.Papp
2,3
&FiroozAflatouni
1
Microcomb-ba sed sources formed by placing an integrated demultiplexer
with an ultra-low power consumption after an efficient o ptical frequency comb
play a key role in many large-scale optical links for data centers and AI systems.
Here, we demonstrate a multi-wavelength multi-port source based on a Kerr
microcomb followed by a monolithically-integrate d demultiplexer, which
autonomously locks to and tracks the comb lines. Mach-Zehnder inter-
ferometer- and ring resonator-based wavelength demultiplexers, imple-
mented using capacitive optical phase shifters with a zero static power
consumption, and a soliton microcomb, with a 200 GHz mode-spacing and
53% efficiency, are implemente d. Using a single control unit for the sequential
control of all phase shifters, a total demultiplexer power consumption of
2.4 mW is achieved, which corresponds to a record demultiplexer energy
consumption of 10fJ/b and 2.5fJ/b for an 8-channel and 32-channel systems at a
data-rate of 32 Gb/s/channel, respectively, significantly improving the demul-
tiplexer energy efficiency compared to the thermally-tuned state-of-the-art
systems.
Wavelength Division Multiplexing (WDM) is a widely adopted techni-
que in optical communication systems for simultaneously transmitting
data by use of multiple wavelength channels over a single optical fiber.
An essential component of a WDM system is the multi-carrier light
source. The spectral purity, number of carriers, wavelength stability,
uniformity, and energy efficiency of the multi-carrier light source
directly affect the key performance metrics of the link such as aggre-
gate data-rate, bit-error-rate (BER), range, and energy efficiency.
Kerr microresonator frequency combs that generate solitons have
been utilized in optical transceivers
1–10
, and they offer several advan-
tages, ranging from increased data capacity in a small footprint to
enhanced signal stability
11,12
. By laser pumping a high-quality-factor
microresonator made of a nonlinear medium, the Kerr effect can be
utilized to generate an optical frequency comb, where a series of
equally spaced optical carriers, or comb lines/modes, within a single
optical channel is formed
13
. The equally spaced coherent comb lines
have a narrow linewidth, making them a good candidate to serve as
optical carriers in optical transceivers to significantly increase the
aggregate data-rate by introducing many parallel communication
channels in a WDM scheme
14
. Furthermore, due to the small footprint
of Kerr microresonators, transceivers utilizing such devices can
achieve a high areal bandwidth density. The high spectral efficiency
offered by Kerr microresonators is particularly beneficial in scenarios
where there is a growing demand for high-bandwidth applications,
such as AI systems, cloud computing, video streaming, and 5G-XG
networks
15–19
. Additionally, Kerr soliton microcombs are typically
resilient to external perturbations and can enhance the overall stability
of the transmitted signals
20
,whichleadstoimprovedsystemperfor-
mance and higher transmission reliability.
In a WDM transmitter, carriers generated within the multi-carrier
source are typically separated, individually modulated, and combined
to form the transmitter output. Figure 1ashowsasimplified block
Received: 11 July 2024
Accepted: 8 June 2025
Check for updates
1
Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, USA.
2
Time and Frequency Division, National Institute of
Standards and Technology (NIST), Boulder, CO, USA.
3
Department of Physics, University of Colorado, Boulder, CO, USA. e-mail: firooz@seas.upenn.edu
Nature Communications | (2025) 16:6387 1
1234567890():,;
1234567890():,;
