Passive Optical Networks

inherent chip material loss, and connector loss. The targeted areas for improve-

ment of insertion loss in PLC-based splitters have been in reducing connector

losses, and improving fiber array and splitting ratio nonuniformity [1]. The

connector loss can be improved from 0.5 dB to 0.15 dB through using high-

quality ferrules and an excellent polishing method. With advances in manufac-

turing processes of the fiber array block and PLC chip, insertion losses from

fiber array nonuniformity and splitting-ratio nonuniformity can be reduced from

0.7 dB to 0.4 dB, and 1.8 dB to 1.0 dB, respectively [2, 4]. Collectively, the excess

insertion losses of PLC-based splitters are currently 1–1.5 dB above the ideal

theoretical splitting loss with a nonuniformity ...