Polymeric wavelength division multiplexing coupler with fiber guide and filter trench fabricated by one-step replication process for bi-directional communication

A polymeric bi-directional wavelength division multiplexing (WDM) coupler for graded-index (GI) plastic optical fiber (PDF) was fabricated and characterized. The device with fiber guides and a filter trench was fabricated by simple one-step soft-lithography process. The insertion loss, the isolation and the directivity of the device at wavelengths of 850 nm and 790 nm was less than 3 dB, more than 20 dB and more than 20 dB respectively by optimally designing the structure. By setting GI-POFs in fiber guides and inserting a WDM filter in a filter trench with passive alignment, bi-directional communication was realized with more than 2.5 Gbps/λ for 150m length.