Tunable thin film filters for the next generation PON stage 2 (NG-PON2)

The next generation passive optical network stage 2 (NG-PON2) is a subject of interest for future access networks. These networks require a lot of issues to be fulfilled as more bandwidth beyond 10 Gb/s, compatibility with legacy PON technologies and more requirements specified in the recommendation ITU-T G989.1. As a primary solution for NG-PON2 time and wavelength division multiplexed PON (TWDM-PON) based on the meeting of FSAN (Full Service Access Network) in April 2012 has been selected. The purpose of this paper is to design a possible wavelength allocation for NGPON2 coexisting with legacy PON technologies. Our main objective is to outline tunable thin film filters which can be used as channel filters in receivers in optical network termination units (ONUs) and are intended for each wavelength plan shown in this paper. The possibility of using the designed filters for extending wavelength plans is discussed, too.