With the technology of free space optical communication, information can be transmitted from the transmitter to receiver wirelessly without the necessity of fiber optic cables. This technology offers system security, extended bandwidth, high data rate, and simple installation. This work aims to improve the optical channel based on the optimization of different optical amplifiers and filters. Performance analysis is carried out using a rectangular optical filter (ROF) and two electrical amplifiers named automatic gain control (AGC) and transimpedance amplifier (TIA). The results are presented in terms of maximum quality factor as a function of link range. The proposed systems (represented by ROF and AGC) brought better performance than traditional one (represented by TIA) via the same link range and data rates used. The findings displayed the progress of the AGC which has better quality factor than TIA and ROF. For instance at 5 m length, the AGC achieves a maximum Q-factor of 12.29, while the ROF and ATI reveal a Q-factor in the range of 9.8 and 7.01, respectively.