Performance tests of angled fiber 3 dB couplers made with drawn silica substrates

A report is presented on a series of tests performed on angled-fiber-type optical couplers fabricated with drawn silica substrates. The couplers use a multilayer dielectric coating, applied directly on an angled fiber interface. Measured performance of the device shows an average near-end crosstalk of -48 and an excess of 0.46 dB. The use of an all silica design for the substrate holding the fiber results in good environmental performance. The simple design and compact nature of the coupler lend themselves to the economical replacement of separate splitters and detectors in single-mode bidirectional systems