Answers are grounded in this paper and cite their sources.
Petermann's mathematical definition of spot size using the modal near field and its derivative is proved to be √2 times the inverse of the RMS width of the observable modal far field. The theory of fibre optics is given in terms of the transformed field, which determines the far field. Dispersion, splice loss and excitation efficiency are discussed.
No takes yet. Share an insight, caveat, or question.
C. Pask (1984) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: