Toptica : Terahertz communication – wireless data transfer at frequencies beyond 100 GHz

http://www.toptica.com/applications/terahertz_applications/terahertz_applications_communication.html
The communications sector represents another terahertz market with significant potential. Wireless communication systems continue to strive for higher bandwidths – and faster data transfer requires higher carrier frequencies. Present-day systems like Bluetooth or WLANs employ bandwidths between a few MHz and several GHz. However, judging from the ever-increasing growth in data rates, it is obvious that these frequency bands will not suffice in the long run, when transfer rates of several 10 Gigabits/second will be needed [1].
 Admittedly, technical challenges have to be met - there are, for instance, no suitable transmission lines, i.e. no terahertz equivalents to fiber-optics - but free-space communication channels (inter-satellite communication, or "hot spots" for wireless download of high-data videos) at frequencies of 100 GHz and above can certainly be envisaged.

During the 2008 Olympic Games in Beijing, scientists from Osaka University and NTT Corp. already demonstrated a 120 GHz data link to transmit uncompressed high-definition images of the game stadiums from the International Broadcasting Center to the Beijing Media Center, across a distance of 1 km [2].

For researchers in the field of terahertz communication, TOPTICA’s cw packages offer a perfect testbed: The terahertz frequency can be set to any value between 50 and 1800 GHz, and is kept precisely constant by means of aninterferometric control scheme. In particular, InP-based terahertz emitters (available from Q03/2010) will unite a high frequency selectivity and record power levels on the 10 µW scale.

References:
[1] Terahertz Communication Lab, Technical University of Braunschweig
[2] Y. Kado and T. Nagatsuma, PIERS Proceedings, Beijing, 42 (2009).