Schematic, simulated and photographic illustrations of silicon photonics based on 3 µm thick silicon-on-on-insulator waveguides. Image credit: Timo Aalto and Mikko Harjanne.
By Dr. Karen Steward
Dr. Timo Aalto outlined how advances in photonic integrated circuits could underpin the next generation of communications, artificial intelligence and sensing technologies during a lecture in the QAMSS series today.
Speaking to an audience of researchers and students, Aalto, from VTT, showcased a unique silicon photonics platform capable of operating across an exceptionally broad wavelength range while integrating metre-long waveguides onto chips just millimetres in size. The technology is opening new possibilities for applications ranging from spectroscopy and communications to optical and radio-frequency beam steering.
The talk, titled Photonic Integrated Circuits for Computing, Communication, Sensing and Imaging, explored how photonic integrated circuits (PICs) are becoming increasingly important as demand grows for faster and more efficient data processing and connectivity.
Asked which application area is likely to see the greatest impact from photonics over the next decade, Aalto said communications currently offer the clearest path to widespread transformation.
“That is a tough question, since all four application domains have the potential for technological revolution,” he said. “PICs will definitely play a very important role in optical connectivity that is necessary to scale up AI and quantum computing, as well as fibre optic, free-space optic and mobile communication networks.”
He added: “Optical communication is the application domain that will have the most certain impact from photonics.”
While communications may be the most immediate beneficiary, Aalto suggested the longer-term possibilities could be even greater. “It is possible, although not yet confirmed, that classical or quantum computing will also be heavily based on photonics,” he said.
He also highlighted the potential for photonic technologies to reach consumers directly through products such as wearable devices and compact sensing systems.
“Potentially the biggest impact could come from the use of PICs in various consumer products, such as wearable sensors and miniaturised lidars,” he said, while noting that competing technologies still create uncertainty in this area.
Despite the rapid progress being made, Aalto identified manufacturing challenges as the key obstacle to wider deployment.
“Assembly and packaging is currently the biggest cost factor in PIC-based products and probably remains to be the biggest challenge also in the future,” he said.
Aalto explained that no single photonics platform is likely to meet every application requirement. Instead, different materials and chip technologies will need to be combined with extreme precision.
“Compared to electronic chips, the photonic chips need much higher alignment accuracy,” he said. “This increases the costs of the products and sometimes cannot meet performance requirements.”
The lecture provided a timely insight into how photonics is moving from specialist research towards technologies that could reshape global communications networks and future computing systems.
About the interviewee
Dr. Timo Aalto, VTT.
Having started silicon photonics research already in 1997, Timo Aalto is one of the pioneers in the field. He works at the VTT Technical Research Centre of Finland, where he leads the Silicon Photonics research team. His research focuses on the micron-scale silicon waveguides that are used to make ultra-compact and low-loss photonic integrated circuits for communication, imaging and sensing applications at near and mid infrared wavelengths. Aalto has contributed to over 120 scientific publications, reviewed several EU projects, journal articles and theses, and coordinated large projects funded by EU, the European space agency, national funding organisations and the industry. He currently coordinates the EU project DYNAMOS and leads the monolithic PIC technology work package in the PIXEurope pilot line. Aalto received his masters and doctoral degrees in optoelectronics technology from the Helsinki University of Technology in 1998 and 2004, respectively.