  We investigate the generation of single photons and photon pairs in a cavity
quantum electrodynamics system of a four-level quantum dot coupled to bimodal
cavity. By tuning frequencies and intensity ratio of the driving lasers,
sub-Poissonian and super-Poissonian photon statistics are obtained in each
nondegenerate cavity mode respectively. Single photon emission is characterized
as zero-delay second-order correlation function g^2(0)~0.15. Photon pair
emission under the two-photon resonance excitation is quantified by Mandel
parameter as Q~0.04. The mean cavity photon number in both scenarios can
maintain large around 0.1. As a result, single photon emission and two-photon
emission can be integrated in our proposed system only by tuning the external
parameters of the driving lasers.
