Résumé | This chapter reviews the characteristics of SOI ridge waveguide birefringence, as governed by the waveguide cross-section geometry, the cladding stress level, and cladding thickness. Typical stress levels in dielectric cladding films such as silicon dioxide and silicon nitride are such that the stress-induced birefringence is of comparable magnitude to the waveguide geometrical birefringence. Therefore the total waveguide birefringence can be precisely controlled by counter-balancing these two factors. The application of this technique for achieving polarization independence in a variety of photonic components is described, as well as an example of polarization splitting. Passive and active tuning of the stress-induced birefringence is discussed. The use of birefringence tuning to enhance the efficiency in optical parametric processes and stress-induced Pockels electro-optic effect are also briefly addressed. © Springer-Verlag Berlin Heidelberg 2011. |
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