Due to achievements in photonics technologies optical transmission systems in core networks have gained a notably increase in transmission speed per single fiber during the last decade [1]. Demand for greater transmission speed has been increasing exponentially because of the impulsive spread of Internet services [2]. Due to above mentioned facts bandwidth intensive applications and exponential Internet traffic growth are continuing to drive the further penetration of optical fiber into the access networks. The use of wavelength division multiplexing (WDM) in the access networks is further defensible in terms of video services support. The main reasons behind the implementation of new generation systems are to meet demand of capacity and user density requirements, while ensuring that the cost per unit bandwidth is lowest possible [3]. The novel concept is dense WDM (DWDM) – direct in which multiple wavelengths are directly connected to each optical access network unit (ONU) [4]. Proposed approach for increasing the transmission capacity is to reduce the channel spacing of a DWDM – direct system to the minimum while keeping the employed optical band-pass filter technologies.