  We introduce the notion of an isotropic quantum state associated with a
Bohr-Sommerfeld manifold in the context of Berezin-Toeplitz quantization of
general prequantized symplectic manifolds, and we study its semi-classical
properties using the off-diagonal expansion of the Bergman kernel. We then show
how these results extend to the case of non-compact orbifolds, and give an
application to relative Poincar\'e series in the theory of automorphic forms.
