Optical Bistability Of Composite Systems With The Quantum Theory

The optical bistability (OB) is an important research branches in the quantum optics. Due to its potential application, such as a switching element in an optical communication system, memory devices, amplifiers and so on, the subject of extensive theoretical and experimental investigations has been intensively studied. Here we primarily deal with the optical bistable-state with the quantum theory. We introduced the optical bistable-state and its classic theory, as well as the correlative quantum knowledge. Then with the quantum theory, two complex systems are separately analyzed:(1)One is a system in a ring cavity consisting of a degenerate optical parametric and N harmonic two-level atoms, as well as an input monochromatic pumping field with the frequencyω_p. At the same time a broadband squeezed vacuum (SV) centered at frequencyω_s is also introduced into the cavity. The system interacts with the SV, which leads to the decay of the system. We derive the corresponding explicit analytical expressional steady-state in the central modeω_p =ω_s, and the result displays optical bistability (OB). In addition, influence of the broadband SV parameters on the optical bistable behavior is analyzed in details.(2)The other system discussed in a high-Q Fabry-Perot cavity contains N two-level atoms, and a Kerr-like medium, as well as an input monochromatic pumping field. Moreover the coupling between atoms and cavity is intensity-dependent. We derive the steady-state bistable behavior of the system, and analyzed the effect of several primary systemtic parameters on the bistable behavior.