WAVEGUIDES

22 Outubro 2019, 09:00 • José Manuel Rebordão

Examples of waveguides; architectures for coupling light into waveguides.

A simple waveguide, a two parallel mirrors waveguide: self-consistency conditions, discretization of angles and wavevector components; field configurations, odd and even modes; relation dispersion; number of modes; set of modes as a basis of functions.

Optical fibers: concept, acceptance angle and Numerical Aperture; information throughput and bandwidth; pulse width increase with propagation; need to reduce the width of the nucleous to reduce the number of modes; limits to the geometrical optics approach.

EM description of step-index cylindrical waveguides: Helmholtz equation in cylindrical coordinates; dependence of azimuthal and radial components on axial component. Solutions of the equations for Ez and Hz with separation of variables: Bessel equations; constrains on the different solutions; constrains on the separation variables; continuity of the tangential components and dispersion relation. Graphical analysis of modes for axial and non-axial modes. Hybrid modes. Monomode waveguides.

 

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Rectangular optical waveguides.

Presentation by Andreia

BIBLIOGRAPHY

Iizuka, Elements of Photonics, Vol. 2, Caps. 9, 11

Saleh B.E.A, Fundamentals of Photonics, Caps. 8, 9