Comments on 'Gaussian beams are fundamentally different from free-space modes' by E.A.J. Marcatili and C.G. Someda

The commenter makes three points about the above-named work (see ibid., vol.QE-23, p.164-7, 1987). Specifically, he points out an apparently contradictory statement, gives another explanation for the interference-like pattern observed at the focus of an optical instrument as a result of excitation of higher modes, and explains why he is of the opinion that the Gaussian beam is a mode of propagation of electromagnetic waves in free space.<
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