  We have created paraexcitons in Cuprous Oxide via resonant two-photon
generation, and examined their population dynamics by means of time-correlated
single photon detection. Confining the excitons to a constant volume in a
harmonic potential trap made with inhomogeneous applied stress along the [001]
axis, we find that paraexcitons are created directly, and orthoexcitons appear
primarily through the well-known excitonic Auger process. Hot excitons are also
created via a three-photon process when the IR laser is non-resonant. Also we
generate excitons with two colliding pulses, and the luminescence is weaker
than that from one beam excitation with same total laser power. These results
show that resonant one-beam two-photon generation of paraexcitons is a
promising way to pursue Bose-Einstein condensation of paraexcitons.
