Integrated optical TE-and TM-pass, acoustically tunable, double-stage wavelength filters in LiNBO3

Abstract

Two types of double-stage, acousto-optical wavelength filters have been fabricated in X-cut, Y-propagating LiNbO3 by an integration of TE-and TM-pass polarisers and acoustooptical mode convenors in a doubly confined acoustical/optical singlemode waveguide. Filter characteristics with narrow bandwidth (<2nm), a tuning range of ∼60nm around λ= 1.55μm and strongly reduced residual sidelobeshave been obtained.