  We demonstrate a technique that generates frequency-entangled photon pairs
with high polarization definition by using a single-period nonlinear crystal
and single pass configuration. The technique is based on the simultaneous
occurrence of two spontaneous parametric down-conversion processes satisfying
independent type-II collinear pseudo-phase matching conditions in periodically
poled stoichiometric lithium tantalate. The generated photon pairs exhibit
non-degenerate Hong-Ou-Mandel interference, indicating the presence of quantum
entanglement in the frequency domain. This method provides a light source
capable of wide-range quantum sensing and quantum imaging or high-dimensional
quantum processing.
