Performance evaluation and analysis of hybrid FSO communication systems using dispersion compensation fiber and EDFA placement optimization

This paper investigates the system performance in a hybrid SMF-FSO communication system that employs the 193.1 THz CW laser, Mach–Zehnder modulator, erbium-doped fiber amplifier (EDFA), and PIN photodiode. The proposed setup consists of 60 km single mode fiber (SMF), which is followed by a 1 km FSO link under varying atmospheric attenuation conditions ranging from 0.3 dB/km to 20 dB/km. To mitigate the chromatic dispersion in the fiber, the dispersion-compensating fiber (DCF) is integrated with partial and full compensation conditions. Furthermore, the placement of EDFA with preamplification and postamplification schemes is also analyzed. The system performance is investigated in terms of bit error rate (BER), received power, Q-factor, and the characteristics of eye diagrams. The simulation results indicate that incorporating DCF improves the quality of the signal under varying atmospheric attenuations, i.e., low and moderate attenuation conditions. The optimized amplifier placement increases the receiver sensitivity, which enhances the system reliability even under adverse weather conditions.