Characteristics of lattice networks and spectral filters built with 2/spl times/2 couplers

Results of numerical experiments on several interferometric networks built with 2/spl times/2 couplers are presented. The networks investigated include resonant and nonresonant lattices, generalized Mach-Zehnder (MZ) configurations and transversally coupled spectral filters. Several novel interferometric configurations and novel properties of known configurations are discussed. The numerical method is based on the concept of a universal coupler and on the generalized analysis of interferometric networks. It has been found that relatively simple configurations can provide the very high spectral selectivity needed in some communication applications and the flexibility desired in various sensor applications. Group delay and loss characteristics are also given.