PhD defence by Stenio Magalhães Ranzini

Title: Optoelectronic receiver in Short Reach Optical Fiber Communications


Principal supervisor: Professor Darko Zibar, DTU Fotonik, Denmark
Co-supervisor: Senior Researcher Francesco Da Ros, DTU Fotonik, Denmark
Co-supervisor: Dr. Vahid Aref, Nokia Bell Labs, Germany

Evaluation Board
Associate Professor Michael Galili, DTU Fotonik, Denmark
Professor Kathy Lüdge, Technische Universität Berlin, Germany
Senior Researcher Daniel Brunner, FEMTO-ST, France

Master of the Ceremony
Associate Professor Anders Clausen, Department of Fotonics, DTU, Denmark


Every time you scroll pages on the internet, listen to online music, play online games or watch a movie in a stream environment, you access information from a cloud. Cloud is the name we give to the place where all this information is stored. To access this information in the cloud, we use optical fibers, which make the connection from you to the cloud fast and reliable with the help of light.


This thesis proposes and studies new techniques that make it possible to transmit high-speed information to longer distances in optical fibers. We have focused the research on using a low-cost communication system called intensity-modulated and direct detected (IM-DD). Our main original contribution is an optoelectronic equalizer that recovers the corrupted information using light and electrons. Specifically, we have used optical filters to divide the optical signal into small pieces and neural-network algorithms (feedforward neural network and reservoir computing) to reconstruct the information. Numerical and experimental analyzes were performed to validate the idea.


Experimental results show that this technique can increase transmission distance by more than eight-fold without sacrificing communication speed.


Fri 29 Oct 21
13:30 - 16:30


The defence will take place online via this Zoomlink and Building 341, auditorium 22 at DTU Lyngby Campus