Enabling high baud rate terabit superchannels

Simple item page
dc.check.date2026-09-30
dc.check.infoControlled Access
dc.contributor.advisorGunning, Fatima
dc.contributor.authorCanas Estrada, Nataliaen
dc.contributor.funderScience Foundation Irelanden
dc.date.accessioned2025-05-22T14:58:42Z
dc.date.available2025-05-22T14:58:42Z
dc.date.issued2025
dc.date.submitted2025
dc.descriptionControlled Access
dc.description.abstractInternet service providers rely on optical systems to transmit and receive data through the optical fibre network, supporting applications ranging from video streaming to autonomous driving. To meet growing user demands, optical communication systems have evolved to maximize spectral efficiency and aggregated data rates by transmitting multiple closely-spaced optical carriers within a single fiber. However, opto-electronic components are reaching their performance limits in terms of electro-optic conversion, bandwidth, and frequency response. Innovative solutions are necessary. Superchannel systems offer a promising approach, utilizing off-the-shelf components to achieve high spectral efficiency by transmitting closely-spaced optical carriers that overlap. The optical carriers are treated as a single entity that collectively deliver multiple terabits per second. These systems, if designed for compact architectures, could be well-suited for integration into photonic integrated chips. A critical component in superchannel systems is the Mach-Zehnder modulator (MZM), used to generate the optical carriers and encode data onto optical carriers through amplitude and phase modulation. However, MZMs are prone to bias drifts, requiring an effective DC bias control for stable operation. This work addresses the challenge of MZM bias drift by first characterizing the behavior of single and nested MZMs to understand their transfer functions. Based on the analysis and results, a simple DC bias monitoring method based on asymmetric dithering signals is proposed. The proposed method allows slope identification when the MZM is biased at quadrature. Time-interleaving is proposed to extend this approach to multiple devices using low-frequency dither signals of varying frequencies to monitor each MZM. This method successfully identifies bias point drifts by analyzing the peak-to-peak and mean power of the low-frequency components of the modulated signal. The proposed technique was experimentally validated in an NRZ-OOK system transmitting at 10, 12.5, and 20 Gbit/s, demonstrating negligible impact on the bit error rate (BER) performance. Additionally, a DC bias control method based on the perturb-and-observe approach was developed and tested in simulations, effectively correcting bias drifts. These findings demonstrate a simple and feasible solution for stabilizing MZMs, ensuring reliable integration into advanced optical communication systems such as superchannels.en
dc.description.statusNot peer revieweden
dc.description.versionAccepted Versionen
dc.format.mimetypeapplication/pdfen
dc.identifier.citationCanas Estrada, N. 2025. Enabling high baud rate terabit superchannels. PhD Thesis, University College Cork.
dc.identifier.endpage157
dc.identifier.urihttps://hdl.handle.net/10468/17569
dc.language.isoenen
dc.publisherUniversity College Corken
dc.rights© 2025, Natalia Canas Estrada.
dc.rights.urihttps://creativecommons.org/licenses/by-nc-nd/4.0/
dc.subjectSuperchannelsen
dc.subjectDC bias controlen
dc.subjectOptical communicationsen
dc.subjectMach-Zehnder modulatoren
dc.titleEnabling high baud rate terabit superchannels
dc.typeDoctoral thesisen
dc.type.qualificationlevelDoctoralen
dc.type.qualificationnamePhD - Doctor of Philosophyen
Files
Original bundle
Now showing 1 - 2 of 2
Thumbnail Image
Name:
CanasEstradaN_PhDThesis_2025.pdf
Size:
11.42 MB
Format:
Adobe Portable Document Format
Description:
Full text E-thesis
Thumbnail Image
Name:
3. 114220539 - Natalia Cañas Estrada - Submission Form.pdf
Size:
436.63 KB
Format:
Adobe Portable Document Format
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
5.2 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Research Theses
College of Science, Engineering and Food Science - Doctoral Theses
Electrical and Electronic Engineering - Doctoral Theses
Tyndall National Institute - Doctoral Theses