It is quite important to enhance and control the optomechanically induced high-order sideband generation to achieve low-power optical comb and high-sensitivity sensing with an integrable structure. Here we present and analyze a proposal for enhancement and manipulation of optical nonlinearity and high-order sideband generation in a hybrid atom-cavity optomechanical system that is coherently driven by a bichromatic input field consisting of a control field and a probe field and that works beyond the perturbative regime. Our numerical analysis with experimentally achievable parameters confirms that robust high-order sideband generation and typical spectral structures with nonperturbative features can be created even under weak driven fields. The dependence of the high-order sideband generation on the atomic parameters are also discussed in detail, including the decay rate of the atoms and the coupling parameter between the atoms and the cavity field. We show that the cutoff order as well as the amplitude of the higher-order sidebands can be well tuned by the atomic coupling strength and the atomic decay rate. The proposed mechanism of enhancing optical nonlinearity is quite general and can be adopted to optomechanical systems with different types of cavity.
Abstract We present a scheme to realize the regulation of single and double transparent windows in a two-cavity optomechanical device. By studying the output field through the two-cavity device, we not only show the transmission spectrum of the probe field and the second-order sideband process, but also analyze the physical mechanism of the induced transparency window and the efficiency of the second-order sideband process. Moreover, the optomechanically induced transparency window and the coupling of two cavities resulting in transparency window are discussed. We find that the transparency windows and the second-order sideband process can be modulated by the power of the control field and the coupling strength between two cavities. Our device is feasible for controlling light propagation, which might have potential application in quantum optical devices and quantum information networks.
Cavity optomechanics, as a cross-discipline between nanophotonics and quantum mechanics, provides a unique platform for investigating optomechanical coupling between photons in microcavities and phonons from mechanical modes. It has a wide range of potential applications in quantum physics, and now it has become a hot topic. A theoretical scheme to enhance the sum sideband generation (SSG) via a two-level atom ensemble is proposed. The effect of the atomic ensemble’s detuning frequency on the efficiency of the SSG is considered by introducing a two-level atom medium. The results indicate that the efficiency of the generating sideband can be significantly enhanced under either red or blue detuning of the atoms, with greater dependence and more pronounced enhancement under the red detuning. In addition, we also consider the effect of pump power, which can effectively enhance the intensity of the output signal by selecting the appropriate pump power. More interestingly, the sensitivity of SSG to atomic detuning also indicates that the precise control of the atomic detuning frequency can achieve the fine-tuning of the SSG process. Furthermore, the cavity-atom coupling strength and atom decay rate are discussed for the transmission characteristics of the sum sideband signals. It is found that the efficiency of SSG can be effectively adjusted by the cavity-atom coupling strength and atom decay rate. The results show that the efficiency of SSG can be significantly improved by optimizing system parameters. The method of enhancing SSG may have potential application prospects in measuring high-precision weak forces and on-chip manipulation of light propagation.
The generation of second-order sidebands and its associated group delay is an important subject in optical storage and switch. In this work, the efficiency of second-order sideband generation in a coupled optomechanical cavity system with a cubic nonlinear harmonic oscillator is theoretically investigated. It is found that the efficiency of second-order sideband generation can be effectively enhanced with the decrease in decay rate of optomechanical cavity, the increase in coupling strength between two cavities and the power of probe field. The slow light effect (i.e., positive group delay) is also observed in the proposed optomechanical cavity system, and can be controlled with the power of control field.
We propose and analyze an effective scheme to enhance the optical higher-order sideband generation in a three-cavity array with local parity-time (
PT) symmetry. In this three-cavity configuration, a single cavity containing a quantum dot (QD) is coupled to an assisted
PT-symmetric combination of two cavities. Beyond the weak-excitation approximation, we derive the analytic formulas used to determine the nonlinear coefficient of the optical second-order sideband (OSS) by employing the perturbation technique. Using experimentally achievable parameters, we identify the conditions under which the assisted
PT-symmetric double-cavity system allows us to modify the transmission of the probe field and improve the efficiency of OSS generation beyond what is achievable in a loss-only QD-cavity system. We examine the influence of the
PT phase transition from unbroken- to broken-
PT regimes on the OSS generation. It is found that the efficiency of optical second-order sideband generation can be significantly enhanced when the assisted double-cavity system is in
PT-symmetric phase, extremely in the vicinity of the transition point. The present results illustrate the potential to utilize
PT-symmetric physical systems for enhancing optical higher-order sidebands and controlling optical frequency combs, as well as to guide the design of experimental implementation.
Abstract Enhancing and controlling optomechanically induced higher‐order sideband generation is essential to achieve high‐sensitivity sensing. This study theoretically explores the amplified charge‐dependent generation of optical second‐order sidebands (OSS) within a cavity optomechanical system, facilitated by an atomic ensemble. Findings reveal that the presence of an atomic ensemble not only enhances OSS generation but also shows a more pronounced charge dependence in the output OSS spectrum compared to a single optomechanical cavity system. This enhancement inspires to explore charge measurements with higher sensitivity. The results demonstrate that the sensitivity of charge measurement can be elevated by over four orders of magnitude when additional atomic ensembles are incorporated. The proposed scheme presents a promising approach for charge measurement and holds significant potential for applications in quantum sensing.