本文提出一种广义的多模式腔光机械系统，其中两光学腔由一束较强的控制场和一束较弱的信号场驱动与同一个机械振子耦合。较弱的信号场将会被该系统完全吸收而不产生任何能量输出，定义该现象为相干完美吸收，并且当相干完美吸收产生时输入信号场的能量将由两个腔场和机械模所分担。改变参数条件，较弱的输入信号场将由一个腔传递到另一个腔而不产生任何的能量损耗，定义该现象为相干完美透射。上述两种现象可由两腔场之间的耦合所操控，并进一步分析了该现象产生的起源和条件。上述两种现象将在全光学领域中的量子信息方面有着潜在的应用。 We present a generalized multi-mode cavity optomechanical system, where two cavity modes with strong control fields and weak signal fields are coupled to a common mechanical resonator. The weak input signal fields will be entirely absorbed by the system without generating any energy output from each of the cavity modes termed coherent perfect absorption (CPA), and the two cavity modes and mechanical mode will share the input probe fields energy when CPA occurs under parameter regimes. With changing the parameter conditions, a weak input signal field will transmit from one cavity to the other cavity without undergoing any energy loss termed coherent perfect transmission (CPT). The above phenomena are dependent on the coupling strength between the two cavity modes in this optomechanical system. The origin and conditions that enable these phenomena to achieve are analyzed, and potential applications in quantum information may be realized in all-optical domain based on such phenomena.
本文提出一种广义的多模式腔光机械系统，其中两光学腔由一束较强的控制场和一束较弱的信号场驱动与同一个机械振子耦合。较弱的信号场将会被该系统完全吸收而不产生任何能量输出，定义该现象为相干完美吸收，并且当相干完美吸收产生时输入信号场的能量将由两个腔场和机械模所分担。改变参数条件，较弱的输入信号场将由一个腔传递到另一个腔而不产生任何的能量损耗，定义该现象为相干完美透射。上述两种现象可由两腔场之间的耦合所操控，并进一步分析了该现象产生的起源和条件。上述两种现象将在全光学领域中的量子信息方面有着潜在的应用。 We present a generalized multi-mode cavity optomechanical system, where two cavity modes with strong control fields and weak signal fields are coupled to a common mechanical resonator. The weak input signal fields will be entirely absorbed by the system without generating any energy output from each of the cavity modes termed coherent perfect absorption (CPA), and the two cavity modes and mechanical mode will share the input probe fields energy when CPA occurs under parameter regimes. With changing the parameter conditions, a weak input signal field will transmit from one cavity to the other cavity without undergoing any energy loss termed coherent perfect transmission (CPT). The above phenomena are dependent on the coupling strength between the two cavity modes in this optomechanical system. The origin and conditions that enable these phenomena to achieve are analyzed, and potential applications in quantum information may be realized in all-optical domain based on such phenomena.
With the rapid development of nano-physics and quantum optics, optico-mechanical coupling system is developing toward the miniaturization and lightweight. The physical characteristics of optical cavity and applications of optic-mechanical devices have received much attention. In this paper, a generalized three-mode cavity optico-mechanical system is presented, the steady-state responses of the system to the characteristics of weak detection of light absorption and dispersion in several different coherent driving modes are studied. Situated in the middle of system is a portable total reflection mechanical oscillator with a reflectance of 100%, and located on each side is a fixed optical cavity mirror with partial transmittance, Three-mode cavity optical mechanical system consists of fixed-mirror, removable-vibrator, fixed-mirror structure. in which the two optical cavities are coupled by coupling a stronger control field and weak probe light with the same mechanical oscillator. Analysis and numerical results show that under the mechanism with different parameters, due to nonlinear effect of pressure, in the three-mode cavity optical mechanical system, there appear some interesting quantum coherent phenomena such as coherent perfect absorption, coherent perfect transmission and coherent perfect synthesis. When coherent perfect absorption occurs, the mutual conversion between input signal power full-field energies and oscillator vibration of internal coherence can be realized, and the law of conservation of energy is satisfied. When relaxation rate due to mechanical oscillator is very small, the coherent perfect transmission is completely transmitted from the system side of the input field to the other side in the case of no loss of energy. And mechanical relaxation rate of the oscillator approaches to zero in the middle, which can ensure that the perfect transmission of the detection field takes place on one side, and the field total reflection and coherent perfect synthesis happen on the other side of. In addition, we alsofind that the adjustment of coupling between cavity and cavity can change the intensity of the probe field of quantum coherent control thereby realizing that the output of the detection field is transformed between coherent perfect absorption and coherence transmission; through simple phase modulation the output direction and input direction of detection field for left cavity-right cavity can swap mutually. So, these dynamic controls in quantum information networks can be used to construct some optical devices with special functions, such as photon switch, photo router, photon exchange machine, etc.
An experimental work [W. J. Wan, Y. D. Chong, L. Ge, H. Noh, A. D. Stone, and H. Cao, Science 331, 889 (2011)] showed that a resonator that contains a loss medium instead of a gain medium enables coherent perfect absorption (CPA) by interference. Here, we propose an alternative approach to realize such a CPA and coherent perfect transmission (CPT) as well as the switching between CPA and CPT in a cavity quantum electrodynamics (CQED) system by applying an external magnetic field. The proposed CPA and CPT scheme is based on the magnetically induced transparency (MIT) configuration, instead of the conventional electromagnetically induced transparency configuration, which offers a sensitive method to tune CPA and CPT and also is conducive to the flexible control of the CPA and CPT scheme. Under the linear and nonlinear excitation regimes, we derive the approximate analytical solutions of the cavity-output power and the CPA criteria of the CQED system, and find that the CPA can occur at different frequencies in both regimes. In the nonlinear excitation regime, the relationship between the cavity-output power and the cavity-input power can show a bistable characteristic by the control of the static magnetic field, and the CPA point is near the turning point of the cavity-input power on the bistable return hysteresis curve. Furthermore, the line shape and the threshold value for optical bistability can be flexibly controlled by varying the magnetic field under experimentally accessible conditions, thus the magnetic field can well tune the CPA. Also, we compare the analytical and numerical results of the cavity-output power in the nonlinear excitation regime, and they are in good agreement. Our results show that the CQED system based on the MIT configuration can be used as a perfect absorber or nearly perfect transmitter, which may have practical applications in optical logic and optical communication devices.
We propose a scheme to achieve CPA not only in the strong-coupling regime but also in the weak-coupling regime. The system under consideration consists of an atomic ensemble coupled to an optical cavity containing an optical parametric amplifier (OPA). We show that when the OPA introduces an effective loss, CPA can occur only in the strong-coupling regime. In contrast, when the OPA provides an effective gain, CPA can emerge in both the weak- and strong-coupling regimes. We further demonstrate that in the weak-coupling regime, CPA cannot occur within the bistable region, whereas in the strong-coupling regime, CPA can indeed appear in the bistable region. Moreover, the output intensity can be flexibly controlled by tuning the effective strength and the phase of the OPA. Our work opens a potential way to design a coherent perfect absorber based on weak coupling mechanism.
We propose a feasible scheme to realize all-optical photon transmission switching in a passiveactive optomechanical system, consisting of one ordinary passive cavity, one active cavity and one common movable membrane oscillator of perfect reflection, driven by two strong control fields and two weak probe fields symmetrically. By means of the gain effect of the active cavity, many novel and valuable phenomena arise, such as frequency-independent perfect reflection (FIPR) first proposed in this paper, adjustable photon bidirectional transmission, phase-dependent non-reciprocity and so on. The relevant parameters used for controlling the all-optical switching are precisely tunable by adjusting the strengths of control fields and the relative phase of probe fields. Furthermore, tunable fast and slow light can be realized in our system by accurately adjusting relevant parameters which is readily and feasible in experiments. These novel phenomena originate from the effective optomechanical coupling and the gain effect provide a promising platform for photonic devices, quantum network node fabrication and quantum information process (QIP).
We theoretically propose a loop-coupled multimode optomechanical system (OMS) with a single-mode cavity, a two-level system (TLS), and a mechanical resonator, which are coupled to each other. With controlled coupling parameters, the loop-coupled multimode OMS can flexibly transform into different OMSs (e.g. cavity OMSs, cavity quantum electrodynamic systems). By simultaneously driving the single-mode cavity using pump and probe fields, we investigate the coherent optical response and transmission spectra for the transparent window and absorption dips. Additionally, the transparent window and absorption dips that induce coherent light propagation were demonstrated. Our findings demonstrate that the transparent window and absorption dips can generate slow (fast) light, and that the control of coupling parameters can modulate optical fields in different OMSs. With further weaving of these coupling parameters, the loop-coupled multimode OMS can be a quantum information processing platform for chip-scale applications.
We explore theoretically the optical response properties in an optomechanical system under an electromagnetically induced transparency condition but with the mechanical resonator being driven by an additional coherent field. In this configuration, more complex quantum coherent and interference phenomena occur. In particular, we find that the probe transmission spectra depend on the total phase of the applied fields. Our study also provides an efficient way to control propagation of a probe field from perfect absorption to remarkable amplification.