Why are the lobe dimensions of the fundamental mode larger than those of the higher modes?
Answers
ANSWER :
Since guided modes in three-dimensional optical waveguides are hybrid modes, vector and stripped at the output so that the “ dropped” wavelength is in the fundamental mode
Answer:
In order to solve a highly non-linear problem by introducing the smallest a priori information, we present a new inverse technique called the ‘roller coaster’ technique and apply it to measure surface wave mode-branch phase velocities. The fundamental mode and the first six overtone parameter vectors, defined over their own significant frequency ranges, are smoothed average phase velocity perturbations along the great circle epicentre–station path. These measurements explain well both Rayleigh and Love waveforms, within a maximum period range included between 40 and 500 s.