Polymeric multi/demultiplexers using light-induced self-written waveguides for cost-effective optical interconnection

Light-induced self-written (LISW) waveguides provide us with a simple method of forming low-loss 3-dimensional optical waveguide components in photopolymers using irradiation from optical fibers. Using simultaneous irradiation from optical fibers fixed to three I/O sockets, onto which VCSELs (vertical surface emitting laser) and PDs (photo diode) can be mounted, we successfully fabricated a polymeric multi/demultiplexer, consisting of a WDM filter and a branching waveguide suitable for a PCS (polymer cladding silica) fiber. A 1 Gbit/s bidirectional full-duplex WDM transceiver module with dual wavelength multimode VCSELs (780 nm and 850 nm) was demonstrated. The typical insertion losses of the module were 4.1 dB for the 780 nm VCSEL and 3.4 dB for the 850 nm VCSEL at room temperature. The receiver sensitivities were -11.8 dBm and -13.6 dBm at 850 nm and 780 nm, respectively.