Squeezing of the multiple-photon-added squeezed thermal state and its Wigner-function evolution in a laser channel

We analytically and numerically investigate the normalization and squeezing features of the multiple-photon-added squeezed thermal state (MPASTS) and its evolution in a laser channel via the integral method for operator ordering. It is found that the normalization constant is proportional to the Jacobi polynomials, and the sum squeezing degree can be weakened by the photon addition for both symmetric and asymmetric operations. Moreover, the nonclassicality of the MPASTS can be enhanced with increase of the photon-addition numbers for the symmetric cases, but decreased as the average photon numbers of the thermal field and the cavity loss of the laser are increased. (paper)