Upgrade of an optical network unit in a 40 Gb∕s time and wavelength- division multiplexed passive optical network using an upstream tunable colorless laser Salem Bindhaiq Abu Sahmah M. Supa’at Nadiatulhuda Zulkifli Redhwan Q. Shaddad Abdallah Mataria Downloaded From: http://opticalengineering.spiedigitallibrary.org/ on 08/03/2014 Terms of Use: http://spiedl.org/terms