the incredible progress of telecommunication technology in all its forms

Today it is possible to be connected with anyone anywhere in the world, using nothing more than a compact device in your pocket. This is only possible thanks to the incredible progress of telecommunication technology in all its forms. For example, thanks to the deployment of optical fiber at the bottom of the ocean, it is possible to transport petabits of data per second between different continents. At the same time, modern data centers are capable of managing and distributing the data of thousands of users in a matter of milliseconds. The development of this infrastructure has enabled the emergence of new ubiquitous services such as Amazon, YouTube, or Uber. The incredible success of these services has driven an explosive demand for new and faster hardware. For example, Amazon spends approximately 20 000 000 000 EUR per year on research and development.

To satisfy this ever-increasing demand for bandwidth and connectivity, the continuous deployment of newer and faster hardware in data centers and mobile networks is needed. The development of new and faster integrated circuits, or ICs, is one of the key innovations needed to realize this new generation of hardware. An IC is a chip containing a complex electronic circuit, usually made of silicon and only a few square millimeters in size. Some of these ICs are made to do calculations (CPUs) and others are made to receive and translate wireless signals (Wi-Fi, 4G) into data your CPU understands.

Figuur 1: Een photonic integrated circuit (PIC) op een printplaat met glasvezelkoppelaar. Deze PIC, ontwikkeld door imec, dient als hogesnelheid optische zender en ontvanger voor datacentra.

During the last years a new type of IC is starting to play an important role, namely the photonic integrated circuit (PIC). A PIC works with light instead of electricity and allows to put an entire optical circuit (lasers, filters and detectors) on a chip of a few square millimeters. Another important advantage of PICs, when compared to conventional optical systems, is that PICs can be fabricated with the same tools and processes that are used to fabricate the ICs in your laptop or smartphone. This means they can be fabricated in large volumes and with great cost-efficiency. At this moment, they play a crucial role in data centers, where they are used as essential building blocks for compact optical transmitters and receivers capable of sending up to 400 Gbit/s. These transmitters and receivers, or transceivers, are currently being developed and offered by companies such as Intel, Facebook and Amazon.

In the Photonics Research Group of Ghent University and imec, we are now researching how these PICs can be used to accelerate the deployment of ultra-fast 5G  networks. For example, we experimentally investigated, for the first time, an optical PIC-based data-transmission link developed for 5G networks. Furthermore, we showed that using a PIC-based optical link can provide beyond state-of-the-art data rates. Moreover, for this demonstration we used silicon PICs that can be easily fabricated on a wafer-scale. This allows for very high volume manufacturing which is necessary for deployment in the 5G networks of the future.

Based on these results obtained in the Photonics Research Group, of Ghent University and imec, we conclude that PICs will play a key enabling role in 5G networks.

Recent journal papers:  doi:10.1109/LPT.2018.2867930, 10.1109/JLT.2020.3021175,  doi:10.1109/lpt.2018.2889537