Long Range-Power Efficient DWDM-Free Space Optical System : Multiplexing in Free Space Optics

Free space optics (FSO) is the branch of optical communication which deals with the wireless transmission of light signal between two points. The medium of transmission is air or free space. Due to this the transmission loss which occurs in fibers is eliminated. Free space optics (FSO) technology has many advantages such as high data rate/ speed and bandwidth. Despite of these it has the drawback of attenuation offered by the different weather conditions which can degrade the system’s performance. So the problem of FSO signal degradation due to atmospheric disorder can be overcome by using wavelength division multiplexing (WDM) in order to achieve high data rate and maximum link range. WDM systems have the potential to transmit multiple signals simultaneously. But the light signals degrade in intensity when they travel a long distance. So it is required to amplify all the light signals simultaneously after a certain interval of light propagation to regain the original signal. So different types of Optical amplifiers are generally used to amplify the light pulses.  This book focuses on design and investigation of DWDM-FSO system in order to enhance the link range with minimum acceptable BER and maximum quality factor at different bit rates under different weather conditions. In this work the link range of 32 channels DWDM-FSO system has been investigated and improved in terms of BER Q-factor eye height and eye opening by using post processed SOA amplifier.