Multi-Wavelength Separation Characteristics in Integrated Acoustooptic Devices for Photonic Switching System

Photonic switching systems in wavelength-division-multiplexed (WDM) networks are discussed. By employing collinear acoustooptic (AO) devices as wavelength selective functional devices, the system structure can be simplified with flexibility in wavelength assignment. As the AO devices, collinear AO wavelength separators and switches consisting of an optical directional coupler are investigated in integrated structures. Integrated optic devices such as WDM demultiplexers/multiplexers, wavelength-selective matrix-switches, and routers for delay time selection in buffer memories are described. Wavelength selective characteristics are theoretically estimated for a material combination of TiO2/Ta2O5/proton-exchanged layers on LiNbO3 substrates. The switching capacity in the switching system consisting of AO devices is evaluated. Issues for employing AO switching devices in WDM networks are also discussed.