The numerical solution on coupling coefficients of corrugated waveguides /

Menteş, Pınar
The problem of propagation and interaction of optical radiation in dielectric waveguides is cast in the coupled-mode formalism. This approach is useful for treating problems involving energy exchange between modes. In this study, the principal features of coupled modetheory are reviewed. A number of guided-wave interactions encountered in guided-wave optics are analyzed using coupled-mode theory. Explicit expressions for the coupling coefficient which play a central role in this theory, are given. Also, an exact analysis, based on local field expansion, is used in order to calculate the coupling coefficient in corrugated waveguide structures having rectangular tooth shape and small tooth height. Expressions for the coupling coefficient in corrugated waveguides with rectangular tooth shape are analyzed based on local mode expansion. Coupling coefficient in corrugated waveguides with arbitrary cross-section is examined. The expressions are exact to first order in the tooth height for any waveguide cross-section. Finally, we compute coupling coefficients for TE modes as a function of tooth height, active layer thickness, and Bragg scattering order for a variety of corrugation shapes. It is shown that the coupling coefficient for sawtooth gratings has a resonans in some cases.


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The effects of an applied electric field on quantum well subband energies are calculated variationally within the effective mass approximation for model potential profiles. The concept of a quasi-bound state is examined critically. For higher electric field values it is shown that the quasi-bound state approximation for the ground and first excited state of the electron, and for the ground state of the hole is valid. (C) 1996 Academic Press Limited
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Citation Formats
P. Menteş, “The numerical solution on coupling coefficients of corrugated waveguides /,” M.S. - Master of Science, Middle East Technical University, 2003.