  We present a method for the generation of correlated photon pairs in desired
orbital-angular-momentum states using a non-linear silica ring fiber and
spontaneous parametric down-conversion. Photon-pair emission under
quasi-phase-matching conditions with quantum conversion efficiency $ 6\times
10^{-11} $ is found in a 1-m long fiber with a thermally induced $\chi^{(2)}$
nonlinearity in a ring-shaped core.
