1971 Journal of Applied Sciences Research, 7(12): 1971-1975, 2011 ISSN 1819-544X This is a refereed journal and all articles are professionally screened and reviewed ORIGINAL ARTICLES Corresponding Author: Ainon Najahah Abd Aziz, Broadband, Network & Security Laboratory, Spectrum Technology Research Division, Faculty of Engineering & Built Environment UKM, Bangi, Selangor. E-mail: najahah@eng.ukm.my New Optical Splitter Design to Enhance the Quality of Optical Signal Ainon Najahah Abd Aziz, Mohammad Syuhaimi Ab-Rahman, Kasmiran Jumari Broadband, Network & Security Laboratory, Spectrum Technology Research Division, Faculty of Engineering and Built Environment UKM, Bangi, Selangor. ABSTRACT In this paper, we introduce a new optical device to replace the 1xN Optical Splitter in passive optical network (PON) to increase the performance of an optical network system in scattered topology. Multi Ratio Optical Splitter (MROS) was developed to increase the signal performance of the network system for customer of different distance. The performance of the network system will be evaluated by its eye diagram and amplitude of the jitter that has been extracted from its eye diagram. For comparison purpose with MROS, a conventional 1x4 Optical Splitter will be used as a benchmark to see the signal quality. MROS was designed using device designing tools that based on beam propagation method (BPM) and integrated into network design simulator for test. Simulation result shows that MROS with the highest ratio gives the widest eye opening of eye diagram. Value of jitter extracted from these eye diagrams supporting this result when it produce jitter with amplitude as low as 0.031 UI compare to conventional 1x4 Splitter with 0.61 UI. Key words: Optical Splitter; Passive Optical Network; Signal Quality. Introduction Fibre-To-The-Home (FTTH) is an emerging technology in fibre optic communication which brings fibre optics directly to the home (M.S. Ab-Rahman, 2009). It provides larger bandwidth and faster delivery speed which is very suitable for ‘triple play’ deliveries that includes video, data and broadcasting service offer by access provider (M.S. Ab-Rahman, 2009; J.H. Song, 2005). There are two types of optical network distribution architecture that can be applied to FTTH since signal from central office need to be distributed among many customers. They are active optical network (AON) and passive optical network (PON) (M.S. Ab-Rahman, 2008). In this research, we are focusing on FTTH-PON, a point to multipoint that using optical splitter in order to serve multiple premises with a single fibre (G. Kramer, 2002). A single fibre was connected to an amount of user, typically 16 to 32 via 1xN optical splitter where N was referred to number of user. In FTTH application, Multi Ratio Optical Splitter (MROS) was designed to replace this 1xN optical splitter to reduce power wastage. This device is based on the design on 1xN optical splitter, but its power not equally distributed to each branch (C. Chaudari, 2001). The advantage of this design is that it can overcome the disparity in distance from one customer (premise) to another, particularly when the premise is outside the accepted radius. In scattered topology where we have customers in various distances, signal power distribution must be customized based on the distance of every premise. Therefore by no excess power will be provided to that area thus the wastage can be avoided. The quality of signal in network system will be analysed using eye diagram. Eye diagram portrays parametric information involving signal gathered from physical effect such as system bandwidth (G. Breed, 2005). Thus, it can be used to determine other parameters such as Q factor, bit error rate (BER) and eye height. Thorough analysis of this diagram can give the user approximation of jitter and signal-to-noise. Q factor is a parameter that directly reflects the quality of a signal of an optical communication system that can be used to monitor the signal quality (S. Ohteru, 1999; J.A. Jargon, 2008). The quality of the signal is getting better with the increasing of Q factor. Quality of signal can be deteriorated by optical noise, nonlinear effects, polarization effects and chromatic dispersion (R. Shi, 2008). Jitter that contributes to significance parametric issues will be extracted from eye diagram. It gives big impact on design, operation and proof of optical device (J. Hancock, 2004). The value of jitter decreases with increment of ratio of optical signal in a waveguide. Jitter comes from deviation of significance instances of a signal from their ideal location in time. Thus it is very important to measure the jitter because it can cause the transmission error especially jitter with amplitude greater than 0.5 unit interval (UI) (L. Angrisani, 2001). Simulation results show that MROS with highest splitting ratio can reduces the jitter amplitude to 0.031 UI compare to conventional 1x4 Splitter that have 0.061 UI.