Patent ID: 6813398
Filing Date: 2004-11-02
Classification: G02F,H04J

Abstract:
In filters fabricated on a birefringent electrooptic substrate, a tunable electrooptic add-drop filter apparatus, the apparatus comprising:(a) two input single mode waveguides; (b) a first beam splitter connected to said waveguides; (c) a polarization converter connected to each of said waveguides after said first beam splitter wherein each said polarization converter includes more than one set of spaced apart, spatially periodic, strain-inducing pads wherein the length of said polarization converter is given by: Ltot32 NcL1+(Ncâˆ’1)L2â€ƒwhere: Nc=an integral number of polarization coupling regions of length L1 and L2=longer regions between said polarization coupling regions in which polarization coupling does not occur; (d) electrodes in proximity to each said polarization converter; (e) a second beam splitter connected to said waveguides after said polarization converter; and (f) two output single mode waveguides connected to said second beam splitter.