One is that at visible optical frequencies the electromagnetic field component parallel to the surface of the metals is non zero;
(One; is; that at visible optical frequencies the electromagnetic field component parallel to the surface of the metals is non zero) Context(One is,List([0, 6))):(the electromagnetic field component parallel to the surface of the metals; is; non zero; L:at visible optical frequencies)
One is,List([0, 6))
One the electromagnetic field component parallel to the surface of the metals
is is
that at visible optical frequencies the electromagnetic field component parallel to the surface of the metals is non zero
non zero L:at visible optical frequencies