Abstract
We study the mathematical properties of the excited coherent states, which are obtained through actions of a photon creation operator of the mode optical field on its corresponding coherent state, by analyzing the minimal set of Klauder's coherent states. Using linear entropy as a measure of entanglement, we investigate in detail the entanglement generated via a beam splitter when an excited coherent state is injected on one input mode and vacuum state is injected on the other one. Finally, we examine the physical properties of the excited coherent states through the Mandel's parameter and the Wehrl entropy and we give the correlation between these parameters and the entanglement of the output state.