GLASS INTEGRATED-OPTICS CIRCUIT FOR 1.48/1.55-MU-M-WAVELENGTH AND 1.30/1.55-MU-M-WAVELENGTH DIVISION MULTIPLEXING AND 1/8 SPLITTING

We demonstrate the integration, in a single glass substrate, of a 1.48/1.55-mum-wavelength multiplexer and a 1.30/1.55-mum-wavelength multiplexer followed by a 1/8 splitter by using potassium- and silver-double-ion-exchange processes. The wavelength multiplexers are based on nonsymmetric three-port Mach-Zehnder interferometers, and symmetrical Y junctions are used for achromatic splitting. The facet-to-facet excess loss in both the 1.48/1.55-mum multiplexer and in the integrated 1.30/1.55-mum multiplexer and 1/8 splitter is less than 2.7 dB. The device can be used, in connection with an erbium-doped fiber, in future wavelength division multiplexing subscriber networks in which amplification is needed in the 1.55-mum-wavelength region.