Polarization Independent Acousto-optic Tunable Filter Using Newly Developed Passive Polarization Beam Splitter in LiNbO3

Abstract

An acousto-optic (AO) tunable filter will be a key component in future wavelength division multiplexing (WDM) systems, because of its wide tuning range with high speed (a few microseconds) and relatively narrow pass bandwidths (~1 nm). For practical WDM systems, polarization independent tunable optical wavelength filters are indispensable. Previously, these devices, using polarization beam splitters (PBS) controlled by applied voltage, had been demonstrated [1][2]. However, it is advisable not to use many high voltage sources for the device operation. The authors present the polarization independent AO filter (Fig. 1), integrating newly developed passive PBS in LiNb03, for the first time.