Effect of atomic coherence on the second- and higher-order squeezing in a two-photon three-level cascade atomic system

A three-level cascade atomic system is considered where atomic coherence can be achieved either by applying an intense pump field or initially preparing the atoms in a coherent superposition of the states. It is predicted that the system, under certain conditions, exhibits almost perfect squeezing outside the cavity. By using the steady-state Q solution it is also shown that certain higher-order squeezing can also be achieved inside the cavity, under a suitable choice of different parameters.