Philosophical question rooted in a practical problem: In a linear defect waveguide, k is conserved along the direction of the waveguide due to its translational symmetry (either discrete or continuous), but k is not conserved in the direction normal to the waveguide (no translational symmetry).
If I have a Bloch mode in the waveguide with a defined frequency at a k-point in the direction parallel to the waveguide optical axis (calculated by MPB) how is the momemtum of the field divided up into the normal and parallel components of the coordinate system? If k was conserved, I could take the k_parallel component, and with the frequency and some trig, calculate the k_perpendicular component. With k not conserved, is the answer this simple? If it is, then isn't k "conserved"? Stated another way (the practical problem I face), in the ray optics limit, how can I calculate the "bounce angle" of the constituent plane waves inside the waveguide defect using the output of MPB ? Thanks. Bruce _______________________________________________ mpb-discuss mailing list [email protected] http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/mpb-discuss
