We propose and demonstrate the Coherent Optical Multiple-Input Multiple-Output (COMIMO) communication technique. In analogy to the spatial diversity in wireless communication, the concept exploits the modal diversity, inherent in a multi-mode fiber (MMF), to transmit independent data channels through a single fiber without the need for wavelength division multiplexing. Central to the MIMO concept is the requirement for sufficient modal diversity in the fiber. The coherent-optics implementation is the key as it ensures that the diversity requirement is met for practically any fiber length and at any data rate. A 2x2 proof-of-concept COMIMO system is experimentally demonstrated.
2004 by The Institute of Electronics, Information and Communication Engineers