ARRAYED HYBRID FILTER COUPLER DEVICE FOR INSERVICE FIBER LINE TESTING

An arrayed hybrid filter/coupler consisting of four waveguide-type wav elength-insensitive couplers and a thin dielectric filter has been dev eloped for application to an in-service optical fibre testing system. The device was designed to combine a 1.31 mum communication light and a 1.55 mum test light with a ratio of 80:20%. The measured performance of a prototype device exhibited an excess loss of 0.6dB, a return los s attenuation of >45dB and a crosstalk attenuation for the test light of >60dB.