  The statistical properties of three-level lasing are investigated
theoretically. It is assumed that the three-level medium is coherently excited
by another laser with an arbitrary photon statistics. It is proved that, under
the specific conditions, the photon statistics of the three-level laser
duplicate the photon statistics of the exciting laser. We call this phenomenon
an induced photon statistics. We suggest to use this to analyze the statistical
properties of a laser involved into a feedback process. Applying this laser for
the coherent pump of a three-level laser, we can follow its photon statistics
by means of direct following the three-level generation. In accordance with [H.
M. Wiseman and G. J. Milburn, Phys. Rev. A, 49, 1350-1366 (1994)], we conclude
that the feedback in itself is unable to generate the non-classical
manifestation in the laser field.
