  We demonstrate theoretically that double angle resolved photoemission
spectroscopy (2eARPES) can directly probe the existence of Cooper pairs away
from the Fermi surface, and can thus provide insight into the characteristic
energy scale around the Fermi surface, the Debye energy, in which electrons are
bound into Cooper pairs. To this end, we compute the photoelectron counting
rate $P^{(2)}$ in two different types of unconventional superconductors, a
$d_{x^2-y^2}$-wave superconductor, and a topological superconductor with a
broken time-reversal symmetry. We show that $P^{(2)}$ provides insight into the
relative strength of intra- and inter-band pairing in multi-band systems, as
well as into the spin polarization of the bands.
