In this growing world, communication to every corner of the globe is the most important factor. Although technology is touching heights it is a great challenge to connect to subscribers present at different territories. For long distance transmission, Dense Wave Length Division Multiplexing (DWDM) has been preferred always as it provides a better bandwidth to operate, but when we comes to short term or short distance transmission it has some drawbacks, such as wide band change, more power consumption, and high cost factor for lower channels. CWDM can easily overcome these disadvantages. In this paper, the performance of 4*15 Gbps optical transmission link for Coarse Wavelength Division Multiplexing (CWDM) based optical network has been analyzed and compared using different photodetectors. Here we’ve compared the performances in terms of Q-Factor (Quality Factor), BER (Bit Error Rate), and eye height in the eye diagram. For experimental setup and simulation, Optisystem-18 software is used.