  We present an analytical formulation of the recent one-shot decoupling model
of Br\`adler and Adami [arXiv:1505.0284] and compute the resulting "Page
Information" curves, for the reduced density matrices for the evaporating black
hole internal degrees of freedom, and emitted Hawking radiation pairs entangled
across the horizon. We argue that black hole evaporation/particle production
has a very close analogy to the laboratory process of spontaneous parametric
down conversion, when the pump is allowed to deplete.
