The performance of free-space optical (FSO) communications that using an optical amplifier (OA) in the scheme of an amplify-received (AR)-relaying has a major drawback in the detection of input signal quality under the effects of turbulence. As an OA is based on a fiber-detection (FD) method to receive and delivers a signal at the amplification process stage, there is an opportunity to implement an optical filter to improve the quality of the input signal. In this paper, as the continuation of previous work on improvement of direct-detection, the optical filter is applied on the AR-relaying of optical signal detection, implementing an OA in the receiver. The novelty proposed in this work is the improvement of FD method where the OF is designed as the integration of cone reflector, pinhole and multi-mode fiber with an OA. The optical filter produces an optical signal, the input of the OA, which minimizes the effects of turbulence, background noise and the fluctuation of the signal spectral. Thus, OA in AR-relaying produces signal output with high power and rise up below threshold level. Additionally, an OF with a lower pinhole diameter produces the best quality of the signal spectral to be delivered into an EDFA. Through this implementation, the performance of optical relaying network on FSO can be significantly improved
