Planar-lightwave-circuit-based duplexer for gigabit-capable passive optical network/gigabit Ethernet passive optical network applications.

We suggest a compact and efficient duplexer using the multimode interference (MMI) effect and the extraneous self-imaging phenomenon for gigabit-capable passive optical network and gigabit Ethernet passive optical network applications. To experimentally evaluate the suggested duplexer, silica-based MMI couplers were tested using light sources with wavelengths of 1310 and 1490 nm. From the experimental results, this device showed relative output powers of -0.3 and -0.7 dBm for the light sources with 1490 and 1310 nm wavelengths, respectively. The return power was measured to be less than -40 dBm.