As data rates continue to climb, passing data between chips using conventional electrical interconnects is proving more and more difficult. The solution is to use light, rather than copper, but it has proved troublesome to integrate this functionality directly onto silicon.
Now, an EPSRC funded group led by Cardiff University and including researchers from UCL and the University of Sheffield, says it has solved the problem and has grown a laser directly onto a silicon substrate. Professor Huiyun Liu, who led the growth activity, said the 1300nm wavelength laser has been shown to operate at temperatures of up to 120°C and for up to 100,000 hours.
Professor Peter Smowton, from Cardiff’s School of Physics and Astronomy, said: “Realising electrically pumped lasers based on silicon substrates is a fundamental step towards silicon photonics.
“The precise outcomes of such a step are impossible to predict in their entirety, but it will clearly transform computing and the digital economy, revolutionise healthcare through patient monitoring and provide a step-change in energy efficiency.
“Our breakthrough is perfectly timed as it forms the basis of one of the major strands of activity in Cardiff University’s Institute for Compound Semiconductors and the University’s joint venture with compound semiconductor specialist IQE.”
Professor Alwyn Seeds, head of the Photonics Group at University College London, added: “The techniques that we have developed permit us to realise the Holy Grail of silicon photonics – an efficient and reliable electrically driven semiconductor laser integrated directly on a silicon substrate. Our future work will be aimed at integrating these lasers with waveguides and drive electronics, leading to a comprehensive technology for the integration of photonics with silicon electronics."
