Richard Clark wrote:

As the last "thin-film" comment reveals, it
has always been about how one mind can encompass two contradictory
positions (total cancellation - non total cancellation) about the same
mechanism (a quarterwave matching section).

In other words: A Troll.

If the incident irradiance is a single frequency coherent signal,
the requirement for TOTAL CANCELLATION OF REFLECTIONS is still
that the index of refraction of the 1/4WL thin-film be the square
root of the medium upon which it is deposited. QED
--
73, Cecil http://www.qsl.net/w5dxp