Semiconductor Laser Grown Directly on Silicon Substrate

A practical laser grown directly on a silicon substrate could transform communications, healthcare and energy systems.

Silicon, the most widely used material for the fabrication of electronic devices, is used in the manufacture of semiconductors, which are embedded into nearly every device in use today, from smartphones and computers to satellite communications and GPS.

While electronic devices have gotten faster, more efficient and more complex, those advances have put a strain on the underlying technology. Researchers have found it increasingly difficult to meet these demands using conventional electrical interconnects between computer chips and systems, and have looked to light as a potential ultrafast connector. But that solution has had its own challenges.

Now a group of researchers in the UK has combined a semiconductor laser — the ideal source of light — with silicon, successfully integrating a laser directly grown onto a silicon substrate.

It is believed the breakthrough could lead to ultrafast communication between computer chips and electronic systems and therefore transform a wide variety of sectors, from communications and healthcare to energy generation.

The EPSRC-funded UK group, led by Cardiff University and including researchers from UCL and the University of Sheffield, have presented their findings in the journal Nature Photonics.

Professor Huiyun Liu, who led the growth activity, said that the 1300-nm wavelength laser has been shown to operate at temperatures of up to 120 °C for up to 100,000 hours.

"Realizing electrically pumped lasers based on (silicon) substrates is a fundamental step towards silicon photonics,” said Cardiff University professor Peter Smowton. "The precise outcomes of such a step are impossible to predict in their entirety, but it will clearly transform computing and the digital economy, revolutionize healthcare through patient monitoring, and provide a step-change in energy efficiency.”

The group’s future work will be aimed at integrating these lasers with waveguides and drive electronics, with the goal of developing comprehensive technology for the integration of photonics with silicon electronics, said professor Alwyn Seeds of University College London.