Keith Dysart wrote:
Do Born and Wolf offer crisp definitions of the boundaries
between coherent, partially coherent, and mutually incoherent?
Or is it a continuum arbitrarily divided into 3 regions for
the purposes of discussion?

The IEEE Dictionary has an interesting definition for
"degree of coherence". Imax means intensity maximum
and Imin means intensity minimum.

Visibility = (Imax-Imin)/(Imax+Imin)

Light is considered "highly coherent" when Visibility
exceeds 0.88 and "partially coherent" when Visibility
is less than 0.88. Incoherent for "very small values"
of Visibility.
--
73, Cecil http://www.w5dxp.com