Optical waveguide analysis using the Fourier transform and its application to intersecting waveguides
Abstract
An analysis method for inhomogeneous waveguides which is effective even for the radiation mode light is derived and applied to study the propagation characteristics of intersecting waveguides. Considering virtual waveguides that include the real waveguide completely, the propagating light is expressed by the Fourier transform with virtual modes set up in the virtual waveguides. Using the concept of the power-flow equation, the Helmholtz equation is tranformed into a difference equation of Fourier coefficients, where weak coupling and paraxial rays are assumed. Applying this method to intersecting waveguides having inhomogeneous index gradients, the dependency of the propagation characteristics of the intersecting angle and the index gradient difference is studied. From these results, light propagation in branching waveguides is found for low intersecting angles. This phenomenon is explained successfully by a model which combines TM(0) and TM(1) modes. Furthermore, the propagation characteristics of inhomogeneous waveguides are simulated and their dependency on the index gradient is studied.
- Publication:
-
Electronics Communications of Japan
- Pub Date:
- June 1984
- Bibcode:
- 1984JElCo..67...87S
- Keywords:
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- Fourier Transformation;
- Gradient Index Optics;
- Optical Waveguides;
- Propagation Modes;
- Coupled Modes;
- Energy Distribution;
- Light Transmission;
- Optics