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: Measuring NIF's enormous shocks

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

Ultra-short X-ray pulses explore the nano world

7 hours ago

Ultra-short and extremely strong X-ray flashes, as produced by free-electron lasers, are opening the door to a hitherto unknown world. Scientists are using these flashes to take "snapshots" of the geometry ...

Measuring NIF's enormous shocks

12 hours ago

NIF experiments generate enormous pressures—many millions of atmospheres—in a short time: just a few billionths of a second. When a pressure source of this type is applied to any material, the pressure ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.