The system optical response in quantum dot molecule (QDM)-embedded coupled cavities with photothermal effect is investigated theoretically. Couple resonator-induced transparency can be found first when only considering the photon tunneling between the double cavities. After implanting QDMs with tunneling effects into the right cavity, three transparency windows are observed due to QDMs and tunneling-induced transparency (TIT) therein. The fourth transparency window is formed due to photothermally induced transparency (PTIT). The results indicate the system absorption can be tuned by changing the system coupling strengths and frequency detunings. Furthermore, the transmission and group delay of the probe field are examined. Especially, the group delay in different transparency windows can be adjusted by the tunneling effect in the QDMs, and the group delay in PTIT can also be controlled by the system coupling strengths, etc. The research provides a new way of using the TIT to control the PTIT, which may be applied to design novel nanophotonic devices.
The system optical response in quantum dot molecule (QDM)-embedded coupled cavities with photothermal effect is investigated theoretically. Couple resonator-induced transparency can be found first when only considering the photon tunneling between the double cavities. After implanting QDMs with tunneling effects into the right cavity, three transparency windows are observed due to QDMs and tunneling-induced transparency (TIT) therein. The fourth transparency window is formed due to photothermally induced transparency (PTIT). The results indicate the system absorption can be tuned by changing the system coupling strengths and frequency detunings. Furthermore, the transmission and group delay of the probe field are examined. Especially, the group delay in different transparency windows can be adjusted by the tunneling effect in the QDMs, and the group delay in PTIT can also be controlled by the system coupling strengths, etc. The research provides a new way of using the TIT to control the PTIT, which may be applied to design novel nanophotonic devices.
ABSTRACT The properties of the output probe field in a qubit‐embedded system containing two coupled cavities are investigated theoretically. A strong pump field and a weak probe field drive the left cavity. The right cavity couples the mechanical oscillator through the photothermal effect. Simultaneously, a qubit couples the right cavity and the mechanical oscillator through Jaynes‐Cummings coupling. Coupled‐resonator induced transparency (CRIT) is realized in the bare coupled cavities firstly. When considering the photothermal effect, photothermally induced transparency (PTIT) can also be achieved. Further, when a qubit is inserted, the qubit‐assisted induced transparency (QIT) is demonstrated. Tunable optical response, along with slow‐fast light at different frequencies, is shown by adjusting the system coupling strengths and frequency detunings. Especially, we demonstrate the group delay in the PTIT can also be manipulated by the photon tunneling between the double cavities.
Abstract We aim to study the properties of the output probe field (OPF) in a system composed of two coupled-optical cavities. A strong pump and a weak probe field drives the left cavity whereas the right-side cavity is coupled to mechanical oscillation via photothermal effect. The two cavities are coupled with optical coupling strength J . Single photothermally induced transparency (PTIT) in a single cavity is realized via thermal effect (2020, Sci. Adv. 6 , eaax8256). Following the idea, we report double PTIT in coupled-cavities system. The control of single to double PTIT is realized in the proposed system by properly adjusting the coupling strength J . We further show the enhancement of slow light by adjusting the coupling strength ( J ) between the cavities. Our proposed scheme facilitates experiments to investigate photothermal effects in an array of optomechanical systems.
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 theoretically investigated the photothermally and optomechanically induced transparency (PTIT and OMIT) in an optomechanical system filled with quantum dots (QDs). In our proposed system, the right mechanical resonator couples with the optical cavity via radiation pressure, and the left mechanical resonator couples with the optical cavity through the photothermal effects. The system is driven by a strong pump field and a weak probe field. It is shown that double transparency windows can be observed due to PTIT and OMIT. When considering the Jaynes‐Cummings coupling between the QDs and the optical cavity, three transparency windows are observed. We also show that the PTIT can be adjusted by the OMIT and the QDs in the optical cavity. What is more, the coupling strength and the frequency detuning can be used effectively to change the system absorption and dispersion in the PITT transparency window. This indicates that the group delay of the probe light can also be manipulated by the system parameters. The obtained results may be applied in the optical communication such as optical buffer, and so forth.
The thermal-induced nonlinear effect in a micro-cavity with small mode volume is extremely important for studying the optical cavity’s physical properties. In this work, we discuss the Kerr effect acting on the photothermally induced transparency (PTIT) and group delays in a photothermal cavity. We analyze the optical bistability with the thermal and Kerr nonlinear effects in the photothermal system, which directly impacts the dynamical stability and the threshold for bistability, eventually leading to an increase in the number of photons in the steady state. Meanwhile, the Kerr nonlinear effect greatly modifies the Fano-like PTIT in the system with photothermal effect, and the window is effectively compensated to symmetrical PTIT by Kerr-induced cavity frequency redshift. A group delay and advance are observed in the phase of the transmitted probe field, which enables light to be stored in the milliseconds range. The results demonstrate the possibility of enhancing or steering the performance of PTIT and group delay in nonlinear optical cavities, and it will find some applications in optical sensing and communications.
Abstract We theoretically study photothermally and optomechanically induced transparency in a hybrid system of two coupled Fabry-Peŕot cavities. The left cavity hosts a dual-species Bose-Einstein condensate driven by pump and probe fields, while the right cavity couples to a mechanical resonator via photothermal effects. By tuning intercavity, optomechanical, and condensate-cavity couplings, both single and multiple transparency windows emerge. Interspecies and intraspecies interactions, along with effective coupling parameters, govern the transparency conditions, while the photothermal coefficient shapes the profiles. Absorption and dispersion spectra reveal that strong coupling enhances slow-light effects and group delay. These findings provide insights into tunable light-matter interactions for optical communication and photonic applications.