Energy loss in a planar waveguide caused by a high refracting and absorbing overlay
| Autor: | W. Karthe, B. Gotz, B. Martin, K. Hehl |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Materials science
business.industry Optical communication Physics::Optics Overlay Cladding (fiber optics) Atomic and Molecular Physics and Optics law.invention Optics Planar law Attenuation coefficient Mode coupling business Nonlinear Sciences::Pattern Formation and Solitons Refractive index Waveguide |
| Zdroj: | Journal of Lightwave Technology. 11:1447-1452 |
| ISSN: | 0733-8724 |
| Popis: | An explanation of the mode behavior in dielectric waveguides with an absorbing, high-refractive-index cladding is given. By considering the total waveguiding system as two separate waveguides, it is possible to attribute the behavior of the complex refractive index of the guided modes to the mixing of the modes of both waveguides. For systems with absorption, so-called quasi-leaky waves are observed in the total system for finite thicknesses of the overlay. For absorptionless systems these leaky waves are found only for infinite thicknesses of the overlay. The occurrence and behavior of these quasi-leaky waves versus the increasing overlay thickness are interpreted. A method for calculating the coupling efficiency of modes at the junction unclad waveguide-clad waveguide, taking into consideration waveguides with absorption, is presented. An experimental method for measuring the absorption coefficient for the guided modes in the cladded waveguide and the coupling losses at the unclad-clad waveguide junction was developed. The measured values are in a good agreement with the theoretical calculations. > |
| Databáze: | OpenAIRE |
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