Benedikt Mayer und
Lisa Janker an der Epitaxieanlage im Walter Schottky Institut
der TU München –
Foto: Uli Benz / TUM
(February 12, 2016) Nanolaser
for information technology
Physicists at the Technical University of Munich (TUM) have
developed a nanolaser, a thousand times thinner than a human hair. Thanks to an
ingenious process, the nanowire lasers grow right on a silicon chip, making it
possible to produce high-performance photonic components cost-effectively. This
will pave the way for fast and efficient data processing with light in the
future.
Ever smaller, ever faster, ever cheaper – since the start of
the computer age the performance of processors has doubled on average every 18
months. 50 years ago already, Intel co-founder Gordon E. Moore prognosticated
this astonishing growth in performance. And Moore’s law seems to hold true to this
day.
But the miniaturization of electronics is now reaching its
physical limits. “Today already, transistors are merely a few nanometers in
size. Further reductions are horrendously expensive,” says
Professor Jonathan Finley, Director of the Walter Schottky
Institute at TUM. “Improving performance is achievable only by replacing
electrons with photons, i.e. particles of light.”
Nanodrähte aus
Gallium-Arsenid auf einer Silizium-Oberfläche - Bild: G. Kolblmüller / TUM
Photonics – the
silver bullet of miniaturization
Data transmission and processing with light has the
potential of breaking the barriers of current electronics. In fact, the first
silicon-based photonics chips already exist. However, the sources of light for
the transmission of data must be attached to the silicon in complicated and
elaborate manufacturing processes. Researchers around the world are thus
searching for alternative approaches.
Scientists at the TU Munich have now succeeded in this
endeavor: Dr. Gregor Koblmüller at the Department of Semiconductor
Quantum-Nanosystems has, in collaboration with Jonathan Finley, developed a
process to deposit nanolasers directly onto silicon chips. A patent for the
technology is pending.
Growing a III-V semiconductor onto silicon requires
tenacious experimentation. “The two materials have different lattice parameters
and different coefficients of thermal expansion. This leads to strain,”
explains Koblmüller. “For example, conventional planar growth of gallium
arsenide onto a silicon surface results therefore in a large number of
defects.”