  In this paper, we demonstrate efficient generation of collinearly
propagating, degenerate pulsed photon pairs based on a bulk Periodically Poled
Potassium Titanyl Phosphate pumped by an ultrashort pulse laser. Using a
single-mode fiber as a spatial mode filter, we detect about 3200 coincidence
counts per second per milliwatt pump power. After we consider main losses in
our experiment, the inferred coincidence counts are about 109000 per second per
milliwatt pump power. This is the very promising for realization of sources for
quantum communication and metrology.
