Design of FTTH demultiplexer based on cascaded wavelength selective coupler

The purpose of this paper is to design and characterize the Multiplexer/Demultiplexer (Mux/Demux) which uses the concept of coupled mode theory. The design is based on cascading the wavelength selective coupler (WSC) devices utilizing commercial specification. The device is designed on silica substrate with compliance of FTTH wavelength such as wavelengths 1310 nm (upstream data/voice), 1480 nm (downstream data/voice), 1550 nm (video) and 1625 nm (testing). The proposal of designed Mux/Demux is used as a router for specific wavelength in order to detect any optical line failure in FTTH network application in which the OTDR launched wavelength (1625 nm) is used as troubleshooting signal. The performance of the devices was modeled using the beam propagation method (BPM-Cad) product from the Optiwave Inc. The device then is characterized in term of output power, insertion loss and true loss measurement.