Low cost beam steering system for FSOC to SMF coupling

Optical communication has become the order of the day due to its very high bandwidth, low noise and reduced number of repeaters. Optical communication systems use an optical fiber to carry the modulated light from one point to other. In other words the optical fibers only replace the electrical wires. In addition, optical computer solves the problem of slowness and heat buildup associated with electronic computers. The present global research aims at fibreless optical communication, something similar to wireless electronic communication. With the transparent medium for light propagation and clear line of sight for communication fibreless optical link is possible for terrestrial and satellite laser communication with proper beam steering system. This paper describes a beam steering technique of a propagating laser beam, which is essential for Free-Space Optical Communication (FSOC) and FSOC to Single Mode Fiber (SMF) coupling. The displacement (tilt) of the arrived laser beam is measured with an instantaneously developed Position Sensitive Detector (PSD) and dynamically compensated using developed low cost Fast Steering Mirror (FSM). The FSM has tilted about azimuthal and elevation axis to steer the laser beam for increasing the efficiency / reliability of coupling. Tilting of the FSM for about 8.5 mrad is achieved in our Laser Communication Laboratory (LCL). Performance of the developed steering system is tested in the real time FSOC link. Experimental results are described and analyzed with the online data table and plots.