1.28 terabit/s (32x40 Gbit/s) wdm transmission system for free space optical communications

We review a novel free space optical (FSO) system that represents a significant breakthrough in the area of FSO communications. The system encompasses a pair of novel terminals: these allow direct and transparent optical connection to common single mode fibers and include a dedicated electronic control unit that effectively tracks the signal beam wandering due to atmospheric turbulence and mechanical vibrations. Further improvement in the signal power stabilization is achieved by means of saturated EDFAs. These solutions allow to realize a new FSO system, which is tested in a double-pass FSO link between two buildings in Pisa, Italy. When the terminals are fed by common WDM signals they allow enough power budget and margins to support a record high capacity transmission (32times40 Gbit/s), with a enormous improvement of stability (six hours with no error burst). During day-long transmission, the system behavior has been deeply characterized to correlate any increase of bit error ratio (BER) to the FSO control parameters.

[1]  E. Ciaramella,et al.  320 Gbit/s (8×40 Gbit/s) double-pass terrestrial free-space optical link transparently connected to optical fibre lines , 2008, 2008 34th European Conference on Optical Communication.

[2]  Katsutoshi Tsukamoto,et al.  Design and evaluation of optical antenna module suitable for radio-on free-space optics link system for ubiquitous wireless , 2008, SPIE LASE.

[3]  L. Rusch,et al.  Suppression of Turbulence-Induced Scintillation in Free-Space Optical Communication Systems Using Saturated Optical Amplifiers , 2006, Journal of Lightwave Technology.

[4]  Yoshinori Arimoto.  Compact free-space optical terminal for multi-gigabit signal transmissions with a single-mode fiber , 2009, LASE.

[5]  Jingshown Wu,et al.  Demonstration of 16 channels 10 Gb/s WDM free space transmission over 2.16 km , 2008, 2008 Digest of the IEEE/LEOS Summer Topical Meetings.

[6]  Theresa H. Carbonneau,et al.  Opportunities and challenges for optical wireless: the competitive advantage of free space telecommunications links in today's crowded marketplace , 1998, Other Conferences.

[7]  J. Cho,et al.  4 x 10 Gb/s terrestrial optical free space transmission over 1.2 km using an EDFA preamplifier with 100 GHz channel spacing. , 2000, Optics express.

[8]  L. Andrews.  Free-space laser propagation: atmospheric effects , 2005, Digest of the LEOS Summer Topical Meetings, 2005..

[9]  Raymond M. Sova,et al.  80 Gb/s free-space optical communication demonstration between an aerostat and a ground terminal , 2006, SPIE Optics + Photonics.