Optomechanically Induced Transparency Research Articles

Enhanced nonlinear interaction effects in a four-mode optomechanical ring

With a perturbative treatment based on the Keldysh Green's function technique, we study the resonant enhancement of nonlinear interaction effects in a four-mode optomechanical ring. In such a system, we identify five distinct types of resonant scattering between unperturbed polariton modes, induced by the nonlinear optomechanical interaction. By computing the cavity density of states and optomechanical induced transparency signal, we find that the largest nonlinear effects are induced by a decay process involving the two phonon-like polaritons. In contrast to the conventional two-mode optomechanical system, our proposed system can exhibit prominent nonlinear features even in the regime when the single-photon coupling is much smaller than the cavity damping.

The effect of oscillator and dipole-dipole interaction on multiple optomechanically induced transparency in cavity optomechanical system

We theoretically investigate the optomechanically induced transparency (OMIT) phenomenon in a N-cavity optomechanical system doped with a pair of Rydberg atoms with the presence of a strong control field and a weak probe field applied to the Nth cavity. It is found that 2N − 1 (N < 10) numbers of OMIT windows can be observed in the output field when N cavities couple with N mechanical oscillators and the mechanical oscillators coupled with different even- or odd-labelled cavities can lead to diverse effects on OMIT. Furthermore, the ATS effect appears with the increase of the effective optomechanical coupling rate. On the other hand, two additional transparent windows (extra resonances) occur, when two Rydberg atoms are coupled with the cavity field. With DDI strength increasing, the extra resonances move to the far off-resonant regime but the left one moves slowly than the right one due to the positive detuning effect of DDI. During this process, Fano resonance also emerges in the absorption profile of output field.

Loss-induced transparency in optomechanics.

We study optomechanically induced transparency (OMIT) in a compound system consisting of coupled optical resonators and a mechanical mode, focusing on the unconventional role of loss. We find that optical transparency can emerge at the otherwise strongly absorptive regime in the OMIT spectrum, by using an external nanotip to enhance the optical loss. In particular, loss-induced revival of optical transparency and the associated slow-to-fast light switch can be identified in the vicinity of an exceptional point. These results open up a counterintuitive way to engineer micro-mechanical devices with tunable losses for e.g., coherent optical switch and communications.

Phase-dependent Fano-shape optomechanically induced transparency.

We present a detailed study of a three-mode-coupling cavity optomechanical system where one mechanical mode and two optical whispering-gallery modes are coupled together. We extend the earlier investigation of regular optomechanically induced transparency (OMIT) [Science330, 1520 (2010)SCIEAS0036-807510.1126/science.1195596] in a more general case. A complete analytical description of the present system is obtained, and quantitative analyses of the Fano-shape OMIT spectrum are provided. It is clearly shown that a sharp and asymmetric Fano-shape OMIT lineshape, which is decided by the phase difference between the probe field and the mechanical driving, can be observed from the probe output.

Optomechanically Induced Transparency at Exceptional Points

Exceptional-point (EP) optics allows for innovative devices, such as a sensor based on a whispering-gallery-mode (WGM) microresonator. Meanwhile, WGM-enabled optomechanics has led to important advances, including optomechanically induced transparency (OMIT). The authors show that unconventional EP features can be observed in OMIT: Tuning the relative angle between two external nanoparticles coupled to the same microresonator causes EPs to emerge periodically, strongly modifying both the transmission rate and group delay of the signal, for a slow-light-to-fast-light switch. This approach is a means to engineer optomechanical EP devices for optical communication and signal processing.

Efficient single-photon switch with an optomechanical cavity coupled to a one-dimensional waveguide

We analyze the single-photon optomechanical induced transparency (OMIT) phenomenon in the waveguide quantum electrodynamics structure consisting of an optomechanical cavity side coupled to a one-dimensional waveguide. A full quantum-mechanical method is used to calculate the single-photon scattering problem. We further provide a proposal to achieve single-photon switch utilizing the single-photon OMIT phenomenon. The influences of dissipations and pulse widths on the efficiency of the switch are also discussed. As a specific example, we show that our approach is experimentally feasible in currently available superconducting quantum circuits.

Microwave-controlled optical double optomechanically induced transparency in a hybrid piezo-optomechanical cavity system

We propose a scheme that is able to generate the microwave controlled optical double optome-chanical induced transparency (OMIT) in a hybrid piezo-optomechanical cavity system, which a piezoelectric optomechanical crystal AlN-nanobeam resonator is placed in a superconducting microwave cavity, and the AlN-nanobeam resonator can be simultaneously driven by both the optical field via the radiation pressure and the microwave field via the piezoelectric interaction. We show that in the presence of a strong pumped optical field applied to the optomechanical crystal cavity through the optical waveguide and an intensely stimulated microwave field applied to the superconducting microwave cavity, a double-OMIT window can be observed in the weak output probe field. The mechanism is that a N-type four-level system can be formed by the system, when two driving fields and a probe field are applied to the corresponding levels, under the effect of quantum interference between different energy level pathways, the third-order nonlinear absorption is enhanced by the constructive quantum interference while the linear absorption is inhibited by the destruc- tive quantum interference, as a result, the double-OMIT window is generated. Our scheme can be applied to realize high-speed optical switches, high-resolution spectroscopy, coherent population trapping or quantum information processing in the solid state quantum systems.

Cross-Kerr effect in a parity-time symmetric optomechanical system.

The cross-Kerr effects between the cavity and the mechanical oscillator in a parity-time symmetric optomechanical system are investigated. It is found that in the double-passive case there appears an asymmetric optomechanically induced transparency (OMIT) spectrum which is composed of a broad absorption peak located around the resonant point and a absorption line at the frequency position mainly determined by the Kerr interaction. The distinctive asymmetry induced by the cross-Kerr coupling is precisely demonstrated by the analytic findings. In the passive-active case, the resonance peaks in the OMIT spectrum are increased with the weak tunnel coupling, which is contrary to that in the double-passive case. When the tunnel coupling is increased up in the strong coupling region, the broad absorption peak and the absorption line in the OMIT spectrum are sequentially changed into the amplification ones, and the central amplification dip is split into two parts due to the normal mode splitting induced by the strong tunnel coupling. This can be used to realize a switching from absorption to amplification by only adjusting the tunnel interaction.

Non-Markovian Effect in Optomechanical System

Most studies on optomechanical systems have been performed under the Markovian approximation. In this paper, we extend the study from the Markovian to the non-Markovian regime. According to the Markovian optomechanically induced transparency (OMIT) theory in Weis et al. (Science 330, 1520, 2010), we propose the non-Markovian counterpart. We find that the non-Markovianity might give rise to negative absorption, i.e., the probe field gains from the environment. By calculating the mean position of the mechanical resonator (MR), we illustrate the effect of non-Markovianity on the dynamics of the moving mirror.

Optomechanically induced transparency with Bose–Einstein condensate in double-cavity optomechanical system**Project supported by the National Natural Science Foundation of China (Grant Nos. 11564034, 11105062, and 21663026) and the Scientific Research Funds of College of Electrical Engineering, Northwest University, China (Grant No. xbmuyjrc201115).

We propose a novel technique of generating multiple optomechanically induced transparency (OMIT) of a weak probe field in hybrid optomechanical system. This system consists of a cigar-shaped Bose–Einstein condensate (BEC), trapped inside each high finesse Fabry-Pérot cavity. In the resolved sideband regime, the analytic solutions of the absorption and the dispersion spectrum are given. The tunneling strength of the two resonators and the coupling parameters of the each BEC in combination with the cavity field have the appearance of three distinct OMIT windows in the absorption spectrum. Furthermore, whether there is BEC in each cavity is a key factor in the number of OMIT windows determination. The technique presented may have potential applications in quantum engineering and quantum information networks.

Optomechanical second-order sidebands and group delays in a Kerr resonator

We theoretically study high-order optomechanically-induced transparency (OMIT) process in a nonlinear Kerr resonator. A frequency shift induced by the Kerr effect, is identified for the optical cavity mode, which results in asymmetric OMIT windows of the signal and its higher-order sidebands. We also find that both the sideband amplitude and its associated group delay sensitively depend on the strength of the Kerr nonlinearity. This indicates the possibility to enhance or steer the performance of OMIT devices with various nonlinear optical cavities.

Coupling mechanical motion of a single atom to a micromechanical cantilever

We design and analyze a hybrid optomechanical setup to achieve an effective coupling between the mechanical motions of a micromechanical cantilever and a single atom trapped inside a cavity, which is mediated by a direct interaction between the micromechanical cantilever and the atomic internal state via the quantum vacuum effect. Moreover, the optomechanical coupling between the mechanical motion of the cantilever and the cavity field can be mediated by the interaction with the atom. Their couplings are demonstrated in detail by analyzing the normal-mode splitting of the mechanical motion and the optical response of the hybrid optomechanical system. It is found that double optomechanically-induced transparency can be observed in the output probe field in the presence of the mediated coupling. In particular, both the width of the splitting peaks and the separation between the two absorption dips increase with the increasing strength of the vacuum coupling and with the decreasing trapped position of the atom. These characteristics can be used to study the strong coupling between a single atom and a massive micromechanical cantilever.

A proposed method to measure weak magnetic field based on a hybrid optomechanical system

Optomechanical systems have long been considered in the field of precision measurement. In this work, measurement of weak magnetic field in a hybrid optomechanical system is discussed. In contrast to conventional measurements based on detecting the change of magnetic flux, our scheme presents an alternative way to measure the magnetic field with a precision of 0.1 nT. We show that the effective cavity resonance frequency will be revised due to the electromagnetic interactions. Therefore, a resonance valley in the transmission spectrum of the probe field will shift in the presence of the magnetic field, and the width of an asymmetric transparency in the optomechanically induced transparency (OMIT) shows a strong dependence on the magnetic field strength. Our results may have potential application for achieving high precision measurement of the magnetic field.

Control of slow-to-fast light and single-to-double optomechanically induced transparency in a compound resonator system: A theoretical approach

The transmission characteristics of probe light field is investigated theoretically in a compound system of two coupled resonators. The proposed system consisted of two high-Q Fabry-Perot resonators in which one of the resonators is optomechanical. Optomechanically induced transparency (OMIT), having relatively large window, is noticed via strong coupling between the two resonators. We investigate tunable switching from single to double OMIT by increasing amplitude of the pump field. We notice that, control of slow and fast light can be obtained via the coupling strength between the two resonators.

Tunable double optomechanically induced transparency in a dual-species Bose–Einstein condensate

A novel technique for generating double optomechanically induced transparency (OMIT) in a weak probe field in an optomechanical system is proposed. This system consists of a cigar-shaped dual-species Bose–Einstein condensate which is trapped inside a high-finesse Fabry–Perot cavity. Analytical solutions are given for the absorption and dispersion spectra. The interspecies interaction and the coupling strengths have, as a result, the appearance of two distinct OMIT windows in the absorption spectrum. Furthermore, the coupling strengths, interspecies and intraspecies interaction strengths are used to control the OMIT behavior. We give a certain set of experimental parameters for observing these phenomena in the laboratory. The technique presented may have potential applications in quantum engineering and quantum information networks.

Optical bistability and four-wave mixing in a hybrid optomechanical system

We explore theoretically the optical bistability and four-wave mixing (FWM) in a hybrid optomechanical system, where the mechanical resonator is simultaneously coupled to a cavity field and a two-level system (qubit). We can use a strong control field driving the cavity to control the bistable behavior of the steady-state photon number, phonon number, and the population inversion. The impact of qubit-resonator coupling strength on the bistable behavior is discussed. Furthermore, the two-level system can significantly modify the output fields of the cavity, leading to double optomechanically induced transparency (OMIT) and the enhancement of the FWM intensity. We find that the distance between the two peaks in the FWM spectrum can be controlled by the qubit-resonator coupling strength, and the peak value of the FWM intensity can be adjusted by the Rabi frequency of the control field.

Optomechanically induced absorption in parity-time-symmetric optomechanical systems

We explore the optomechanically induced absorption (OMIA) in a parity-time- ($\mathcal{PT}$-) symmetric optomechanical system (OMS). By numerically calculating the Lyapunov exponents, we find out the stability border of the $\mathcal{PT}$-symmetric OMS. The results show that in the $\mathcal{PT}$-symmetric phase the system can be either stable or unstable depending on the coupling constant and the decay rate. In the $\mathcal{PT}$-symmetric broken phase the system can have a stable state only for small gain rates. By calculating the transmission rate of the probe field, we find that there is an inverted optomechanically induced transparency (OMIT) at $\ensuremath{\delta}=\ensuremath{-}{\ensuremath{\omega}}_{M}$ and an OMIA at $\ensuremath{\delta}={\ensuremath{\omega}}_{M}$ for the $\mathcal{PT}$-symmetric optomechanical system. At each side of $\ensuremath{\delta}=\ensuremath{-}{\ensuremath{\omega}}_{M}$ there is an absorption window due to the resonance absorption of the two generated supermodes. Comparing with the case of optomechanics coupled to a passive cavity, we find that the active cavity can enhance the resonance absorption. The absorption rate at $\ensuremath{\delta}={\ensuremath{\omega}}_{M}$ increases as the coupling strength between the two cavities increases. Our work provides us with a promising platform for controlling light propagation and light manipulation in terms of $\mathcal{PT}$ symmetry, which might have potential applications in quantum information processing and quantum optical devices.

Straightforward method to measure optomechanically induced transparency.

We demonstrate a simple method to measure optomechanically induced transparency (OMIT) in a Fabry-Perot based system using a trampoline resonator. In OMIT, the transmitted intensity of a weak probe beam in the presence of a strong control beam is modified via the optomechanical interaction, leading to an ultra-narrow optical resonance. To retrieve both the magnitude and the phase of the probe beam, a homodyne detection technique is typically used. We have greatly simplified this method by using a single acousto-optical modulator to create a control and two probe beams. The beat signal between the transmitted control and probe beams shows directly the typical OMIT characteristics. This method therefore demonstrates an elegant solution when a homodyne field is needed but experimentally not accessible.

Optical-response properties in an atom-assisted optomechanical system with a mechanical pump

We investigate the optical-response properties of a coherent-mechanical pumped optomechanical system (OMS) coupled to a Λ-type three-level atomic ensemble. Due to the optomechanical and the cavity-atom couplings, the optomechanically induced transparency (OMIT) and electromagnetically induced transparency (EIT) phenomena could both be observed from our proposal. In the presence of a coherent mechanical pump, we show that the OMIT behavior of the probe field exhibits a phase-dependent effect, leading to the switch from OMIT to optomechanically induced absorption or amplification, while the feature of EIT remains unchanged. The distinctly different effects of the mechanical pump on OMIT and EIT behavior assure us that the absorption (amplification) and transparency of the output probe field can be simultaneously observed. Moreover, a tunable switch from slow to fast light can also be realized by tuning the phase and amplitude of the mechanical pump. In particular, the presence of the atomic ensemble can further adjust the group delay, providing additional flexibility for achieving the tunable switch.

Precision Mass Measurement with Optomechanically Induced Transparency in an Optomechanical System

We present a scheme for all-optical precision mass sensing with squeezed field in an optomechanical system in terms of optomechanically induced transparency (OMIT). We demonstrate that the splitting of the two peaks of the OMIT, which is almost inverse proportion to square root of the accreted mass landing on nanomechanical resonator (NAMR). We also show that the mass measurement scheme for the squeezed fields can be robust against temperature and cavity decay in somehow. Specifically, the precision measurement is from the noise spectrum, for these reasons, our scheme may provide a new paradigm for precision measurement based on the noise in the optomechanical system.