Glass integrated optics circuit for 1.48/1.55- and 1.30/1.55-µm-wavelength division multiplexing and 1/8 splitting

We demonstrate the integration, in a single glass substrate, of a 1.48/1.55-µm-wavelength multiplexer and a 1.30/1.55-µm-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-µm multiplexer and in the integrated 1.30/1.55-µ m 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-µm-wavelength region.