Internal communication signals in a stored program controlled system comprising a plurality of units configured to process signals are provided by a free space optical beam line which is proximal to all of the plurality of units. The free space beam line is configured to contain optically encoded signals...http://www.google.com/patents/US6993260?utm_source=gb-gplus-sharePatent US6993260 - Interconnecting processing units of a stored program controlled system using free space optics
