I have a question about waveguides:(adsbygoogle = window.adsbygoogle || []).push({});

Say your input is an electromagnetic field of a certain time frequency, energy distribution, polarization. Its time frequency is above the cut-off frequency of many of the allowed modes of the waveguide.

The allowed modes are orthogonal functions (whatever they are: TE, TM, TEM). Is that always true? Can the set of allowed modes be an non-orthogonal set?

Once we inject the input beam in the waveguide, Does its energy distributes

a)in all the allowed modes with equal energy.

b)only in those modes that, by superposition, would recreate the initial input field field the best (initial_field= a*mode1+b*mode2+c*mode3+...). (it would only be approximate since we don't have an infinite amount of basis terms to work with but just the allowed ones.

c)Or can the energy even be all channeled in just one of the modes somehow, higher than the fundamental one?

d)none of the above.

Thanks again

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# Waveguiding light

Can you offer guidance or do you also need help?

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