  Nonclassical states are an important class of states in quantum mechanics,
especially for their applications in quantum information theory. Optomechanical
systems serve as an invaluable platform for exploring and harnessing these
states test bed for search and application of such states. In this study, we
focused on the studied the mirror-in-the-middle optomechanical system. We
observed that in the absence of losses, a coherent state evolves into a
entangled one. Furthermore, we demonstrate that the generation of a
Schr\"odinger-cat state depends on the optomechanical coupling. We exactly
solved the Gorini-Kossalokowinki-Sudarshan-Lindblad master equation,
highlighting the direct influence of the reservoir on the dynamics when
mechanical losses are considered. We later discussed vacuum one-photon
superposition states to obtain exact entanglement dynamics using concurrence as
a quantifier. Our results show that the overall entanglement of the system is
attenuated by mechanical losses in the mirror.
