We investigate the probe-field transmission in a hybrid cavity quantum electrodynamic (CQED) system, where one optical cavity containing a quantum dot (QD) with high cavity dissipation is coupled to another auxiliary cavity with a high quality factor. We also investigate the hybrid system operating in the weak coupling regime of the light-matter interaction via comparing the QD photon interaction with the dipole decay rate and the cavity field decay rate. It is shown that the dipole induced transparency (DIT) regime similar to electromagnetically induced transparency (EIT) can be achieved due to the destructive interference of the cavity field in the weak coupling regime, which is extremely significant for the field of semiconductor CQED. The auxiliary cavity plays a key role in the hybrid system, which affords a quantum channel to affect the probe transmission leading to enhanced DIT. Further, DIT induced coherent optical propagation properties such as fast and slow light effects are also investigated based on the hybrid system for suitable parametric regimes. By controlling the coupling strength J and the decay rate ratio δ of the two cavities, tunable and controllable fast-to-slow light propagation can be achieved. This study provides a promising platform for understanding the dynamics of QD-CQED systems and may open up promising on chip applications in quantum information processing.
We investigate the probe-field transmission in a hybrid cavity quantum electrodynamic (CQED) system, where one optical cavity containing a quantum dot (QD) with high cavity dissipation is coupled to another auxiliary cavity with a high quality factor. We also investigate the hybrid system operating in the weak coupling regime of the light-matter interaction via comparing the QD photon interaction with the dipole decay rate and the cavity field decay rate. It is shown that the dipole induced transparency (DIT) regime similar to electromagnetically induced transparency (EIT) can be achieved due to the destructive interference of the cavity field in the weak coupling regime, which is extremely significant for the field of semiconductor CQED. The auxiliary cavity plays a key role in the hybrid system, which affords a quantum channel to affect the probe transmission leading to enhanced DIT. Further, DIT induced coherent optical propagation properties such as fast and slow light effects are also investigated based on the hybrid system for suitable parametric regimes. By controlling the coupling strength J and the decay rate ratio δ of the two cavities, tunable and controllable fast-to-slow light propagation can be achieved. This study provides a promising platform for understanding the dynamics of QD-CQED systems and may open up promising on chip applications in quantum information processing.
The coherent light-matter interaction has drawn an enormous amount of attention for its fundamental importance in the cavity quantum-electrodynamics (C-QED) field and great potential in quantum information applications. Here, we design a hybrid C-QED system consisting of a quantum dot (QD) driven by two-tone fields implanted in a photonic crystal (PhC) cavity coupled to an auxiliary cavity with a single-mode waveguide and investigate the hybrid system operating in the weak, intermediate, and strong coupling regimes of the light-matter interaction via comparing the QD-photon interaction with the dipole decay rate and the cavity field decay rate. The results indicate that the auxiliary cavity plays a key role in the hybrid system, which affords a quantum channel to influence the absorption of the probe field. By controlling the coupling strength between the auxiliary cavity and the PhC cavity, the phenomenon of the Mollow triplet can appear in the intermediate coupling regime, and even in the weak coupling regime. We further study the strong coupling interaction manifested by vacuum Rabi splitting in the absorption with manipulating the cavity-cavity coupling under different parameter regimes. This study provides a promising platform for understanding the dynamics of QD-C-QED systems and paving the way toward on-chip QD-based nanophotonic devices.
Using a single diamond nitrogen-vacancy (NV) center embedded in a waveguide-coupled photonic crystal (PC) nanocavity and driven by a classical laser field, we investigate optical transmission and group delay characteristics of the hybrid system operating in the weak-coupling regime. It is found that double electromagnetically induced-transparency (EIT) transmission peaks and slow- and fast-light propagation inside the EIT-like windows can be realized with practical system parameters. The double-frequency transparency of the input light expands the frequency range of EIT and may improve the controllability of EIT in this composite PC-NV system. The present system also provides a way to achieve integrated photonic slow- and fast-light devices for applications requiring multiple EIT effect in a PC platform.
Dipole-induced transparency (DIT) is one of the most well-known transparency effects in quantum optics and has wide applications in scalable quantum information processing and quantum computation. However, most of the existing literatures only focuses on the DIT effect with coherent dipole-cavity coupling, thus its universality in other types of coupling is still to be clarified. Here, we propose a feasible scheme to realize dissipative dipole-cavity coupling with the assistance of a highly dissipative microcavity, and explicitly exhibit cavity-mode attraction. We then investigate the DIT effect in a cavity-waveguide system with attractive cavity modes and find that it can still be achievable even though the probe light is resonant with two attractive cavity modes. Furthermore, we reveal its underlying transparency mechanism with eigenfrequencies and the effective susceptibility of the dipole-cavity system, and show that its transparency lies in the destructive interference of two attractive cavity modes with splitting damping rates instead of splitting resonance frequencies in coherent coupling. Moreover, we find that the attractive and repulsive phenomena of the effective susceptibility, which also plays an important role in the DIT effect, exist in the dipole-cavity system. Our findings may not only be of importance for gaining a more comprehensive understanding on the DIT effect, but also have potential applications in quantum networks.
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.
Ability to tune the group velocity of a light pulse is of great importance for optical communication applications and realization of quantum information processing. Tunability of group velocity can be achieved by using either optical or electronic resonances. Tunability of an optical resonance depends on the change in refractive index of the cavity material. However, since electro-optical coefficients of non-engineered materials are quite small, the tuning range of optical resonances by electric field is narrow. This makes tuning by electric field impractical for most applications. Quantum dot (QD) coupled to a photonic crystal cavity is a useful hybrid system exhibiting nonlinear features. In this work, we analyze the use of quantum dot - optical cavity hybrid systems to engineer nonlinear waveguides susceptible to electric fields. We start by theoretically analyzing the optical pulse propagation at low-photon number excitation limit in a periodically arranged strongly coupled quantum dot - photonic crystal system. A one dimensional periodic array of evanescently coupled photonic cavities (coupled resonator optical waveguides, CROWs) containing non-interacting quantum dots allows us to tune the group velocity and the bandwidth of the pulse by adjusting the cavity/QD coupling. Tunable group velocity can be achieved by applying an external electric field which will result in a significant decrease in the cavity/QD coupling because of DC Stark effect. We also show that, using this approach, light pulses can be slowed down or stored by compressing the pulse bandwidth adiabatically and reversibly. Adiabatic bandwidth compression can be achieved by slowly decreasing the coupling strength when the light pulse is inside the coupled resonator optical waveguide. The energy splitting and the coupling constant after applying electric field is calculated by using perturbation theory for two level systems. With our approach, nonlinear materials highly susceptible to electric fields can be engineered in low-excitation regime.
This study investigates the tunable propagation of optical pulses in a three-level system of coupled quantum dots. The system forms an effective closed configuration, supporting strong quantum coherence and controllable light–matter interactions. Using the density matrix formalism, we analyze the quantum dynamical response under the influence of both a weak probe and a strong control field, with inter-dot tunneling acting as a key tunable parameter. Our results reveal that both the tunneling strength (Te) and control field Rabi frequency (Ωc) play crucial roles in shaping the system’s optical properties. We observe the emergence of electromagnetically induced transparency-like windows, the splitting and shifting of dispersion peaks, and the formation of absorption doublets and transparency windows. The real and imaginary parts of the electric permittivity exhibit pronounced sensitivity to these external controls. Furthermore, the group index and group velocity are shown to be highly tunable, enabling transitions between slow-light and fast-light regimes. Detailed analysis of temporal pulse dynamics demonstrates the ability to achieve controllable delay and advancement of optical pulses, depending on the interaction between Te and Ωc. These findings highlight the potential of such quantum dot systems for dynamic photonic control, including applications in optical buffering, reconfigurable delay lines, coherent switching, and quantum information processing. The demonstrated tunability and coherence effects make this platform a promising candidate for next-generation optoelectronic and quantum photonic technologies.