Adjustable quantum coherence effects in a hybrid optomechanical system

We propose a system for achieving some adjustable quantum coherence effects, including the normal-mode splitting(NMS), the optomechanically induced transparency(OMIT), and the optomechanically induced absorption(OMIA). In this system, two tunnel-coupled optomechanical cavities are each driven by a coupling field and coupled to an atomic ensemble.Besides, one of the cavities is also injected with a probe field. When the system works under different conditions, we can obtain the NMS, the OMIT, and the OMIA, respectively. These effects can be flexibly adjusted by the tunnel coupling between the two cavities, the power of the coupling lasers, and the coupling strength between the atomic ensembles and the cavity fields. Furthermore, we can realize the OMIT even if the oscillating mirrors have relatively larger decay rates.     

Optomechanically induced amplification and perfect transparency in double-cavity optomechanics

We study optomechanically induced amplification and perfect transparency in a double-cavity optomechanical system. We find that if two control lasers with appropriate amplitudes and detunings are applied to drive the system, optomechanically induced amplification of a probe laser can occur. In addition, perfect optomechanically induced transparency, which is robust to mechanical dissipation, can be realized by the same type of driving. These results indicate important progress toward signal amplification, light storage, fast light, and slow light in quantum information processes.     

原子辅助光力系统中快慢光的量子调控

随着纳米科技以及半导体技术的迅猛发展,光力诱导透明、快慢光和光存储以及其他在光力系统中发现的量子光学和非线性光学效应成为人们目前研究的热点.本文将薄膜腔光力系统同被束缚在腔中的二能级冷原子系综相耦合,通过直接在薄膜振子上引入弱辅助驱动场来研究该原子辅助光力系统中原子和相位对量子相干性质及其快慢光的调控.经过分析发现,通过改变辅助驱动场的强度可直接实现对光力诱导透明窗口深度的调控,通过改变辅助场与探测场之间的相位差,可实现输出的探测场在"吸收"、"透明"和"增益"之间相互转换,进而对弱探测场进行动态调控实现光开关.与此同时,还发现系统的群延迟时间随相位差的改变呈周期性变化.通过调节相位差及原子数,不但可以改变群延迟时间,还可实现快慢光之间的相互转换.     

Tunable optomechanically induced transparency and fast–slow light in a loop-coupled optomechanical system

We theoretically explore the tunability of optomechanically induced transparency(OMIT) phenomenon and fast–slow light effect in a loop-coupled hybrid optomechanical system in which two optical modes are coupled to a common mechanical mode. In the probe output spectrum, we find that the interference phenomena OMIT caused by the optomechanical interactions and the normal mode splitting(NMS) induced by the strong tunnel coupling between the cavities can be observed. We further observe that the tunnel interaction will affect the distance and the heights of the sideband absorption peaks. The results also show that the switch from absorption to amplification can be realized by tuning the driving strength because of the existence of stability condition. Except from modulating the tunnel interaction, the conversion between slow light and fast light also can be achieved by adjusting the optomechanical interaction in the output field. This study may provide a potential application in the fields of high precision measurement and quantum information processing.     

Ideal optomechanically induced transparency generation in a cavity optoelectromechanical system

The ideal optomechanically induced transparency effects of an output probe field are investigated in a cavity optoelectromechanical system, which is composed of an optical cavity, a charged mechanical resonator, and a charged object.Although the charged mechanical resonator damping rate is nonzero, the ideal optomechanically induced transparency can still appear due to the non-rotating wave approximation effect in the system. The location of optomechanically induced transparency dip can be controlled via the Coulomb coupling strength. In addition, we find that both the transparency window width and the maximum dispersion curve slope are closely related to the optical cavity decay rate.     

参量放大器腔中光力诱导透明与本征模劈裂性质

研究了在含有光学参量放大器的光力学腔中关于弱探测光的光力诱导透明与本征模劈裂的性质.研究发现,光学参量放大器的驱动场相位和非线性增益值的大小对光力诱导透明窗口宽度和本征模劈裂性质有非常重要的影响,特别是当控制光频率工作在光力学红边带下,通过适当调制相位和非线性增益可以实现比空腔时(没有光学参量放大器时)还狭窄的光力诱导透明窗口,此时伴随着陡峭的色散曲线.这些研究结果有利于在光力耦合系统中实现快慢光、光存储等量子信息处理过程.     

Interconversion of photon-phonon in a silica optomechanical microresonator

In an optomechanical resonator, the optical and mechanical excitations can be coherently converted, which induces a transparency window for a weak probe laser beam. Here, we report an experimental study of transient optomechanically induced transparency(OMIT) using the silica microsphere with the breathing modes. The transient OMIT behavior obtained are in good agreement with theoretical calculations. In addition, the coherent interconversion between optical and mechanical excitations that can be used for light storage and readout has also been studied here. Our experimental results indicate that the light storage is closely related to the process of OMIT, and the photon-phonon conversion can be further applied to optical wavelength or optical mode conversion.     

双光力诱导透明窗口的可调特性

提出一个杂化腔光力系统理论方案,利用两纳米机械振子间的库仑耦合作用实现弱探测光的双光力诱导透明窗口.研究边带可分辨区域和红失谐情况下双光力诱导透明窗口的可调特性.数值计算表明:两纳米振子间的库仑作用可有效地使单光力诱导透明窗口劈裂为双透明窗口.随着库仑耦合强度的增大,两透明窗口间的距离对称性地拉大;其次,光力腔衰减率的改变对两透明窗口的位置和深度无影响,仅对两透明窗口的宽度产生细微改变,测量精度可在坏腔情形下得到很好的保持;另外,仅增加参量放大器的非线性增益参量将使两透明窗口变宽,而引入驱动参量放大器的光场相位,利用相位匹配可以产生比空腔情形更加狭窄陡峭的双透明窗口,可用于比空腔情况更加精密的测量.     

Tunable Multiple Optomechanically Induced Transparency with Squeezed Fields in an Optomechanical System

A tunable multiple windows optomechanically induced transparency (OMIT) with a squeezed field is investigated in a system consisting of an optomechanical cavity coupled to a charged nanomechanical resonator (NAMR) via Coulomb interaction. Such a multiple OMIT can be achieved by adjusting the frequency of the charged NAMR and can be observed even with a single-photon squeezed field. In addition, this multiple OMIT for the quantized fields can be robust against cavity decay and environmental temperature. Specifically, the model under our consideration might be applied to precision measurement the frequency difference of two NAMRs within the reach of current techniques.     

Tunable Optomechanically Induced Absorption in a Hybrid Optomechanical System

We study the tunable optomechanically induced absorption (OMIA) with the quantized field in the system, which consists of a driven cavity and a mechanical resonator with a super-conducting charge qubit via Jaynes-Cummings interaction. Such a OMIA can be achieved by controlling the strength of the Jaynes-Cummings interaction. Moreover, our work shows this OMIA for the quantized fields can be robust against cavity decay in somehow. With the combination of optomechanically induced transparency (OMIT), our proposal may have paved a new avenue towards quantum photon router.     

回音壁微腔光力系统的相干控制与完全相干透射

本文研究了两侧同时输入的回音壁模谐振双微腔光力系统中电磁诱导透明的相干调控.通过改变双微腔两侧探测场的强度比值及相位差,可以有效控制电磁诱导透明窗口的宽度和深度,对探测场的吸收和色散等性质实施显著的影响,并且能够在特殊频率处产生关于探测场的完全相干透射现象.     

Double optomechanically induced transparency in a Laguerre-Gaussian rovibrational cavity

The optomechanically induced transparency (OMIT), an optomechanical analogue of electromagnetically induced transparency, is a very interesting interference phenomenon. Recently, the studies on the OMIT have been extended to double-OMIT by integrating more optical or mechanical subsystems such as mechanical oscillators, coupled cavities, and atoms in vibrational cavity. In this paper, we demonstrate the double-OMIT can be observed in Laguerre-Gaussian (L-G) rovibrational cavity which was proposed by Bhattacharya et al. (2008) [40], an analog of the double-OMIT in vibrational cavity. The double-OMIT in this research is naturally resulted from a single rovibrational mirror which vibrates and rotates simultaneously, rather than by integrating several subsystems as previously. We numerically examine the influence of the various factors on the double-OMIT and discuss its features and physics behind them in detail. In addition, we discuss the Stokes field generated via the four-wave mixing process in the L-G rovibrational cavity.     

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.     

Measuring orbital angular momentum of vortex beams in optomechanics

Measuring the orbital angular momentum (OAM) of vortex beams, including the magnitude and the sign, has great application prospects due to its theoretically unbounded and orthogonal modes. Here, the sign-distinguishable OAM measurement in optomechanics is proposed, which is achieved by monitoring the shift of the transmission spectrum of the probe field in a double Laguerre–Gaussian (LG) rotational-cavity system. Compared with the traditional single LG rotational cavity, an asymmetric optomechanically induced transparency window can occur in our system. Meanwhile, the position of the resonance valley has a strong correlation with the magnitude and sign of OAM. This originally comes from the fact that the effective detuning of the cavity mode from the driving field can vary with the magnitude and sign of OAM, which causes the spectral shift to be directional for different signs of OAM. Our scheme solves the shortcoming of the inability to distinguish the sign of OAM in optomechanics, and works well for high-order vortex beams with topological charge value±45, which is a significant improvement for measuring OAM based on the cavity optomechanical system.     

Optomechanically Induced Mode Transition and Spectrum Enhancement in a Microresonator System

Optomechanics describes the interconnection between the terahertz optical field and mechanical microwave field, making it appealing in the context of nanophotonics and quantum information science. Here, the optomechanically induced mode transition and spectrum enhanced phenomenon in an optomechanical microcavity system are studied. An optical filter that is limited by the bandwidth of the mechanical mode is built. The analytical model is presented by considering a microresonator system which supports two electromagnetic modes and a single mechanical mode. Through the filtering of mechanical resonator, the optical spectral width becomes similar to the mechanical resonator bandwidth which can go beyond the limit of the cavity quality factor. It is found that the transition between the optomechanically induced transparency and the optomechanically induced absorption can be observed by tuning the coupling between the microresonator and the waveguide. Moreover, the controllable nonreciprocal excitation of the system can also be observed.     

Triple optomechanical induced transparency in a two-cavity system

We theoretically investigate the optomechanical induced transparency(OMIT) phenomenon in a two-cavity system which is composed of two optomechanical cavities. Both of the cavities consist of a fixed mirror and a high-Q mechanical resonator, and they couple to each other via a common waveguide. We show that in the presence of a strong pump field applied to one cavity and a weak probe field applied to the other, a triple-OMIT can be observed in the output field at the probe frequency. The two mechanical resonators in the two cavities are identical, but they lead to different quantum interference pathways. The transparency windows are induced by the coupling of the two cavities and the optical pressure radiated to the mechanical resonators, which can be controlled via the power of the pump field and the coupling strength of the two cavities.     

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.     

Reversible waveform conversion between microwave and optical fields in a hybrid opto-electromechanical system

We present a scheme of reversible waveform conversion between microwave and optical fields in the hybrid opto-electromechanical system. As an intermediate interface, nanomechanical resonator optomechanically couples both optomechanical cavities in the optical and microwave frequency domains. We find the double-optomechanically induced transparency and achieve coherent signal waveform bi-directional transfer between microwave and optical fields based on quantum interference. In addition, we give an analytical expression of one-to-one correspondence between the microwave field and the optical output field, which intuitively shows the reversible waveform conversion relationship. In particular, by numerical simulations and approximate expression, we demonstrate the conversion effects of the three waveforms and discuss the bi-directional conversion efficiency and the bandwidth. such a hybrid opto- and electro-mechanical device has significant potential functions for electro-optic modulation and waveform conversion of quantum microwave-optical field in optical communications and further quantum networks.     

Controllable Photon Transport in a Three-Mode Optomechanical System with the Non-Rotating Wave Approximation Effect

We propose a scheme for realizing controllable photon transport in a three-mode optomechanical system comprising one cavity and two mechanical modes. We found that the non-rotating wave approximation effect can cause the ideal optomechanically induced transparency of the output field. The effects of the cavity mode decay rate on the width of the optomechanically induced transparency window, the dispersion curve slope are discussed in the resolved sideband regime and the unresolved sideband regime.

     

电磁感应双光子带隙的产生和控制

基于电磁感应透明技术, 通过求解原子的密度矩阵方程和电磁场的传输矩阵方程, 研究了被行波场和驻波场共同耦合的一个四能级冷原子介质的稳态光学特性, 发现在特定参数下能够产生一个几乎完美的双光子带隙结构, 在这两个光子带隙对应的频率区域内反射率都均匀地超过95%. 通过改变耦合场的强度和频率, 可以方便地调节这两个光子带隙的位置和宽度. 这一双光子带隙结构可用来实现全光路由和全光开关, 有望在全光信息网络中获得应用.