Tunable Ti:LiNbO3 waveguide filter for long-wavelength (λ = 1.3-1.6-μm) multiplexing/ demultiplexing

Wavelength multiplexing is an important and well-established technique for increasing the Information capacity of lightwave systems.1 Most reported multimode multiplexer/demultiplexer components are bulk-type devices; however, for single-mode applications, waveguide devices offer potential advantages. The wavelength selective Ti:LiNbO3 directional coupler2 is particularly attractive because of its potential for broad electrical tunability and for simultaneously providing highspeed signal encoding.