Spin lasers in the fast lane: New concept for ultrafast lasers developed

Oct 28, 2011

Electrical engineers in Bochum, Germany, have succeeded in developing a new concept for ultrafast semiconductor lasers. The researchers make clever use of the intrinsic angular momentum of electrons, called spin, to successfully break the previous speed barriers. The new spin lasers have the potential to achieve modulation frequencies of well above 100 GHz in future. This is a decisive step towards high-speed data transmission, e.g. for the Internet of tomorrow. The researchers report on their results in the Applied Physics Letters.

Optical data transmission by semiconductor lasers is a basic prerequisite for the globally networked world and today's information society. The ever increasing degree of networking and the desire to exchange larger amounts of data are the driving force behind the development of ever faster optical data transmission systems. The maximum speed of conventional has long been a limiting factor - typical modulation frequencies are currently at levels well below 50 GHz.

By using spin lasers, Bochum's researchers were able to overcome the previous limits for the modulation speed. Whereas in conventional lasers, the spin of the electrons injected is entirely arbitrary, in spin lasers, only electrons with a previously determined are used. By injecting these spin-polarised electrons, the laser is forced to work simultaneously on two laser modes with different frequencies.

"This frequency difference can easily be tuned using the so-called birefringence in the resonator, for example by simply bending the " said Dr. Nils Gerhardt. By coupling the two laser modes in the microresonator, oscillation with a new frequency occurs, which can theoretically reach well over 100 GHz. The researchers around Dr. Gerhardt obtained their results in the collaborative research centre 491 of the Universities of Bochum and Duisburg-Essen ("Magnetic Heterostructures: Spin Structure and Spin Transport").

Explore further: Sensitive detection method may help impede illicit nuclear trafficking

More information: N.C. Gerhardt, M.Y. Li, H. Jähme, H. Höpfner, T. Ackemann, and M.R. Hofmann: "Ultrafast spin-induced polarization oscillations with tunable lifetime in vertical-cavity surface-emitting lasers", Appl. Phys. Lett. 99, 151107 (2011), DOI: 10.1063/1.3651339

Provided by Ruhr-University Bochum

5 /5 (5 votes)
add to favorites email to friend print save as pdf

Related Stories

Spin-polarized electrons on demand

Jan 21, 2009

Many hopes are pinned on spintronics. In the future it could replace electronics, which in the race to produce increasingly rapid computer components, must at sometime reach its limits. Different from electronics, where whole ...

Spin-polarized electrons on demand

Jan 15, 2009

Many hopes are pinned on spintronics. In the future it could replace electronics, which in the race to produce increasingly rapid computer components, must at sometime reach its limits. Different from electronics, where whole ...

Recommended for you

Device turns flat surface into spherical antenna

Apr 14, 2014

By depositing an array of tiny, metallic, U-shaped structures onto a dielectric material, a team of researchers in China has created a new artificial surface that can bend and focus electromagnetic waves ...

User comments : 0

More news stories

CERN: World-record current in a superconductor

In the framework of the High-Luminosity LHC project, experts from the CERN Superconductors team recently obtained a world-record current of 20 kA at 24 K in an electrical transmission line consisting of two ...

Glasses strong as steel: A fast way to find the best

Scientists at Yale University have devised a dramatically faster way of identifying and characterizing complex alloys known as bulk metallic glasses (BMGs), a versatile type of pliable glass that's stronger than steel.

Low Vitamin D may not be a culprit in menopause symptoms

A new study from the Women's Health Initiative (WHI) shows no significant connection between vitamin D levels and menopause symptoms. The study was published online today in Menopause, the journal of The North American Menopa ...

Astronomers: 'Tilt-a-worlds' could harbor life

A fluctuating tilt in a planet's orbit does not preclude the possibility of life, according to new research by astronomers at the University of Washington, Utah's Weber State University and NASA. In fact, ...