Sub-Poissonian radiation of a one-atom two-level laser with incoherent pumping

The quantum statistical properties of the radiation of a one-atom two-level laser with incoherent pumping are analyzed. Solution of the Liouville equa tion for the density operator in the basis of Fock states shows that statio nary radiation from a single-mode laser with incoherent pumping can be in a squeezed (sub-Poissonian) stationary state if the rate of spontaneous deca y is lower than the rate of cavity losses and the pump rate. Inside the cav ity the Fano factor reaches F = 0.85 (15% squeezing). Multiple squeezing (F = 0.19) is possible in the transient lasing regime. Significant squeezing obtains at the cavity output; the spectral Fano factor at zero frequency is 0.36 under optimal conditions. (C) 1999 American Institute of Physics. [S1 063-7761(99)00404-7].