We study theoretically the features of the output field of a quadratically coupled optomechanical system assisted with three-level atoms. In this system, the atoms interact with the cavity field and are driven by a classical field, and the cavity is driven by a strong coupling field and a weak signal field. We find that there exists a multi-window transparency phenomenon. The width of the transparent windows can be adjusted by controlling the system parameters, including the number of the atoms, the powers of the lasers driving the atoms and driving the cavity, and the environment temperature. We also find that a tunable switch from fast light to slow light can be realized in this system.
We study theoretically the features of the output field of a quadratically coupled optomechanical system assisted with three-level atoms. In this system, the atoms interact with the cavity field and are driven by a classical field, and the cavity is driven by a strong coupling field and a weak signal field. We find that there exists a multi-window transparency phenomenon. The width of the transparent windows can be adjusted by controlling the system parameters, including the number of the atoms, the powers of the lasers driving the atoms and driving the cavity, and the environment temperature. We also find that a tunable switch from fast light to slow light can be realized in this system.
We theoretically investigate a multimode quadratic coupling optomechanical system (OMS) assisted with N cold Λ-type three-level atoms. The coupling interaction between two mechanical membranes (MR1 and MR2) and the cavity is quadratic. The three-level atoms interact with an external controlling field and an internal cavity field. The optical cavity is driven by a strong coupling field and a weak probe field. In the resolved sideband regime, four transparency windows are obtained due to the atomic coherence and quadratic coupling in the absorption spectrum for the suitable choice of the controlling parameters. We analyze how to vary the number of the transparency window dips and to adjust their mutual spacing by changing the controlling parameters such as strength of the quadratic coupling between MR1 (MR2) and the cavity, the collective coupling strength between the atomic ensemble and the cavity field, the Rabi frequency associated with the coupling interaction between the controlling field and the three-level atom, power of the coupling field, different frequencies and decay rates of MR1 (MR2), decay rate of the cavity field, and the environmental temperature. Further, we also demonstrate the normal-mode splitting in the generated Stokes and anti-Stokes field in the OMS, where the changing collective coupling strength affects the splitting width of the output field at the Stokes (anti-Stokes) frequency.
In recent years, due to the rapid development of nano science and advanced semiconductor technology, one is able to observe more significant quantum optomechanical effects as optomechanical system turns smaller in size. Optomechanically induced transparency, fast and slow light, optical storage as well as other quantum optical and nonlinear optical effects have become the focus of research. On the other hand, the optomechanical systems coupled to other small subsystems (such as atoms, quantum dots, single electron transistors, etc.) also attract great attention in research. This is because the coupling system has not only provided more degrees of freedom for quantum manipulation, but also opened up more channels for classical and quantum information transfer. In this paper we study the optomechanically induced transparency and fast/slow light phase control in atom-assisted optomechanical cavity. Unlike the traditional systems, in this model the mechanical resonator is directly driven by a weak auxiliary driving field. We therefore find that with the change of amplitude ratio and phase difference between the auxiliary driving field and the probe field, the absorption and dispersion properties of the whole system and the group delay time vary accordingly. In the absence of auxiliary field, we observe the spectral features of the hybrid electromagnetically induced transparency and optomechanically induced transparency (OMIT) in an atom-cavity-oscillator tripartite optomechanical system. When there exists no phase difference between the auxiliary field and the probe field, we find that the membrane resonance absorption is enhanced with the increase of auxiliary field strength at resonance, causing the the optomechanically induced transparency to be suppressed, and therefore we can modify the amplitude of auxiliary field to control the depth of the OMIT window. When keeping amplitude ratio between the auxiliary field and the probe field unchanged, the modification of the phase difference between the auxiliary field and the probe field directly affects the we can not only realize the manipulation of OMIT window depth, but also control the transformation of tunable optical switch among "absorption", "transparent" and "gain" of the system. Therefore, through changing the phase of auxiliary field and probe field, we can not only realize the manipulation of OMIT window depth, but also control the transformation of tunable optical switch among "absorption" , "transparent" and "gain". In the meantime, we find that the system’s group delay time varies periodically with the change of phase difference. It is worth noting that by adjusting the phase difference and the atomic number, we can not only change the magnitude of the group delay, but also realize the conversion between slow light and fast light effect.
Abstract We investigate the tunable multicolor optomechanically induced transparency and the effect of slow/fast light in a hybrid electro-optomechanical system, in which a degenerate optical parametric amplifier (OPA) and a Λ − type three-level atomic ensemble are placed in a optical cavity with two oscillator modes. The system is driven by a strong pump field and a weak probe field, respectively. Multicolor transparency windows appear in the output field under the atom-photon-OPA-phonon-phonon coherent interaction. And the position and width of the transparent port of the output field can be manipulated by properly modifying the different parameters of the subsystem. We also research the slow/fast light effect related to phase and group delay in the probe field. Our proposal provides a great flexibility for phonon storage and has some potential applications in quantum information processing.
We theoretically investigate the phenomenon of electromagnetically induced transparency (EIT) of a weak probe field in hybrid optomechanics with a single three-level (Λ-type) atomic system. We report that, in the presence of optomechanical coupling and two transition coupling parameters of three-level atom (TLA), there occurs three distinct multiple EIT windows in the probe absorption spectrum. Moreover, the switching of multiple windows into double and single EIT windows can be obtained by suitably tuning the system parameters. Furthermore, the probe transmission spectrum have been studied. Based on our analytical and numerical work, we explain the occurrence of slow and fast light (superluminal) regimes, and enhancement of superluminal behaviour in the probe field transmission. This work demonstrates great potential in multi-channel waveguide, fiber optics and classical communication networks, multi-channel quantum information processing, real quality imaging, cloaking devices and delay lines & optical buffers for telecommunication.
Abstract We investigate the phenomenon of optomechanically induced transparency assisted by a hybrid two-cavity optomechanical system. The system consists of two optical cavities and four mechanical resonators, and each optical cavity is filled with two-level atomic ensembles. Our study demonstrates that the characteristics of optomechanically induced transparency vary with different coupling parameters. Specifically, the number of transparent windows increases with the introduction of atomic ensembles and Coulomb interaction. Furthermore, the positions of the transparent points can be manipulated by the coupling parameters. It is found that increasing the Coulomb coupling between mechanical oscillators shifts the transparent points further apart. Furthermore, we also explore the slow/fast light effect by analyzing the phase and group delay of the probe field. Our approach enables the control of multiple optomechanically induced transparency and provides potential applications in quantum information processing.
Abstract We investigate the optomechanically induced transparency in a hybrid optomechanical system, which consists of two optical cavities and a mechanical resonator. The two-level and three-level atomic ensembles are trapped in the two optical cavities, respectively. We focus on the changes in the number and width of transparency windows and the position of transparent points under different conditions influenced by various interactions. Five transparency windows can be observed when all the interactions are on. The introduction of two-level and three-level atomic ensembles can increase the number of transparency windows and also provide better flexibility for controlling the width of the transparency windows. Specifically, the two-level and three-level atomic ensembles contribute one and two transparency windows, respectively. The stronger coupling results in the larger transparency windows and movement of the transparent points. Moreover, we also study the slow/fast light phenomenon through the variation of phase and group delay. These results may contribute to the research of nonlinear optics and have potential applications in optical signal processing and communication.