In communication applications the installation of new optical fiber is extremely difficult, impossible, or just expensive. For example, in certain high rise cities organizations wish to install a secure network between buildings without utilizing the public utility. In other applications such as satellite to satellite communications the laying off fiber is not an option. For these situations the only option is the utilization of free space communications. Heretofore this has always been done through radio waves. Transmitting data optically is superior to radio wave transmission due to its low beam divergence and faster modulation rate. Additionally free space communications is based on line-of-sight and is very difficult to intercept. 1550nm also has excellent transmission characteristics in the water absorption peaks and is an excellent choice for this application.
SemiNex laser diodes have demonstrated the highest output power and long-term reliability for free space optical communications, even in space. Suitable products include