Symmetric Waveguide Structure Research Articles

Simple control of Ti-diffused LiNbO 3 waveguide profile and propagation characteristics

Modification of the optical characteristics of Ti-diffused Z-propagating lithium niobate waveguides by proton exchange and annealing is described. This reversible technique can tune refractive index, form buried symmetric waveguide structures and alter the single-mode propagation wavelength.

Eigenmode analysis of symmetric parallel waveguide couplers

An analysis of a laterally symmetric parallel waveguide structure has been carried out by using symmetric and antisymmetric eigenmodes in the coupled mode equations. As opposed to modes of each individual guide, eigenmodes are orthogonal and therefore comply with coupled mode formalism. Of particular interest has been the popular configuration <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Z</tex> -cut LiNbO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> with Wave propagation along the crystal <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Y</tex> -axis. The theory shows that output versus voltage characteristics are nonperiodic in voltage, and furthermore, they are asymmetric if the eigenmodes are not equally excited. The uniform electrode coupler can easily be explained in terms of eigenmode coupling and interference.