Wigner functions of multiple-photon excited coherent states

Wigner functions in phase space are reconstructed for the excited coherent stateswhich are generated by applying the inverse of k-Boson operators repeatedly to the coherent states. The non-classicality of these states is discussed by calculating their Wigner functions in Fock-state space. Numerical results show that these excited coherent states always reveal non-classical characteristicsno matter whether the excited number k is even or oddand also the corresponding non-classicality is more obvious with the number k increasing.