Observation of electromagnetically induced transparency in a ring cavity

A scheme to observe Electromagnetically induced transparency (EIT) in an optomechanical system is proposed in the current paper. We treat a narrowband squeezed field as the weak probe field. We find that EIT dips exist in the output field. Moreover, the dependence of the EIT dips on the effective cavity detuning Δ and the input power ζ are explored. We show that the width of the EIT dips can be controlled by the parameters ξ and the detuning Δ.     

Enhancement of electromagnetically induced transparency cooling by an optical cavity

We theoretically investigate an enhanced electromagnetically induced transparency （EIT） cooling method by introduc- ing a high finesse cavity. We find that the quantum destructive interference that is induced by the EIT effect and the cavity coupling can eliminate all of the heating effects in the cooling process by choosing appropriate parameters. Compared with the EIT cooling scheme, a lower final temperature can be obtained under the same conditions in our scheme.     

Intracavity electromagnetically induced transparency

The effect of intracavity electromagnetically induced transparency (EIT) on the properties of optical resonators and active laser devices is discussed theoretically. Pronounced frequency pulling and cavity-linewidth narrowing are predicted. The EIT effect can be used to reduce classical and quantum-phase noise of the beat note of an optical oscillator substantially. Fundamental limits of this stabilization mechanism as well as its potential application to high-resolution spectroscopy are discussed.     

Enhancement of the cavity ringdown effect based on electromagnetically induced transparency

We show that the unique absorption and dispersion properties of the electromagnetically induced transparency can be used effectively to relax the conditions for observing the cavity ringdown effect (CRE), which can be useful in applications of CRE in ultrasensitive detection of chemical species. A more straightforward and simple method is used to model the interesting CRE.     

Non‐electromagnetically induced transparency mechanisms for slow light

We show how the pump‐induced sharp holes in homogeneously or inhomogeneously broadened absorption line shapes can be used for the production of ultra‐slow light. We present a detailed discussion of underlying concepts and results on the pump power dependences of the group index and the bandwidth–delay product. Further, we discuss experimental results, which are in agreement with theoretical predictions.     

Birefringence in electromagnetically induced transparency

(4)He 2 (3)S(1) --> 2 (3)P transitions at 1083 nm were laser probed in the presence of radiation that coupled the 2 (3)P level with the 3 (3)S(1) level in a ladder scheme. The metastable helium that was used was produced in a rf discharge. Significant atomic birefringence was detected, in addition to complete electromagnetically induced transparency. A simple theoretical model explains the experimental results.     

多窗口可调谐电磁诱导透明研究

当两束激光以Λ-构型作用于三能级原子系统并满足双光子共振条件时，探测激光场吸收谱呈现电磁诱导透明(EIT)特征.若再加一个微波控制场作用于该三能级系统的两个低能级跃迁之间，会导致探测吸收特性明显变化，EIT窗口将发生劈裂.通过求解相应的密度矩阵方程，揭示了外加微波场作用下EIT窗口的变化规律，并给出了相应的缀饰态解释.研究结果表明，在适当的条件下, 电磁诱导透明呈现三重结构，而EIT窗口的频率位置取决于微波控制场的拉比频率及频率失谐量.因此通过改变微波控制场的参数可以实现多EIT窗口的频率调谐. 关键词： 电磁诱导透明 量子相干 频率调谐 多窗口EIT     

Observation of intracavity electromagnetically induced transparency in Cs vapor coupled with a standing-wave cavity

The cavity transmission spectrum is experimentally investigated in Λ-type three-level atoms coupled to a standing-wave cavity system. It is shown that the dark-state polariton peak is not generated at resonance but rather at off-resonance. The theoretical analysis reveals that the absence of an on-resonance dark-state polariton peak is mainly caused by the strong absorption of the intracavity medium to the probe cavity mode counterpropagating with the coupling field due to the Doppler shift in the hot atoms. Moreover, the optimal frequency position of the cavity mode for an efficient dark-state polariton peak is also demonstrated.     

Ultrafast control of slow light in THz electromagnetically induced transparency metasurfaces

In this paper,we experimentally demonstrate ultrafast optical control of slow light in the terahertz(THz) range by combining the electromagnetically induced transparency(EIT) metasurfaces with the cut wire made of P~+-implanted silicon with short carrier lifetime.Employing the optical-pump THz-probe spectroscopy,we observed that the device transited from a state with a slow light effect to a state without a slow light effect in an ultrafast time of 5 ps and recovered within 200 ps.A coupled oscillator model is utilized to explain the origin of controllability.The experimental results agree very well with the simulated and theoretical results.These EIT metasurfaces have the potential to be used as an ultrafast THz optical delay device.     

Stopping light in a waveguide with an all-optical analog of electromagnetically induced transparency

We introduce a new all-optical mechanism that can compress the bandwidth of light pulses to absolute zero, and bring them to a complete stop. The mechanism can be realized in a system consisting of a waveguide side coupled to tunable resonators, which generates a photonic band structure that represents a classical analogue of the electromagnetically induced transparency. The same system can also achieve a time-reversal operation. We demonstrate the operation of such a system by finite-difference time-domain simulations of an implementation in photonic crystals.     

里德伯电磁感应透明中的相位

本文在典型的里德伯电磁感应透明系统中研究弱探测场在相互作用原子系统中的传播特性,重点关注基于偶极阻塞效应的探测场相位的合作光学非线性行为.通过与探测场透射率和光子关联作对比,发现相位的光学响应具有新特性:共振和Autler-Townes劈裂条件下相位对入射场强和初始光子关联不敏感,而在两者之间的频率范围内相位响应具有非线性特征,尤其在经典光频率处最显著.此外,提高主量子数和原子密度都会促进相位的非线性效应.综上,与探测场透射率和光子关联一样,相位可以作为合作光学非线性的另一个标识来刻画非线性现象,对里德伯电磁感应透明研究是一个有力的补充.     

Polarization of four-wave mixing with electromagnetically induced transparency

The dependence of four-wave mixing (FWM) generated in Rubidium (Rb) vapor with electromagnetically induced transparency (EIT) window on polarizations of the incident fields is studied both theoretically and experimentally. The polarization properties of FWM signal under diverse laser polarization configurations are studied and compared. The results indicate that FWM signal is linear polarized when all incident fields are linear polarized. However, FWM becomes elliptical polarized if any incident field is elliptical polarized. Moreover, the polarizations of the incident fields also influence the dressing effect of the coupling field on FWM process. As the polarization of coupling field (or probe field) varying from linear to circular, the dressing effect gets stronger. By controlling the polarizations of the incident beams polarizations, we can manipulate the polarization state of FWM signal and the dressing effect as well.     

Dark-state polaritons in electromagnetically induced transparency

We identify form-stable coupled excitations of light and matter ("dark-state polaritons") associated with the propagation of quantum fields in electromagnetically induced transparency. The properties of dark-state polaritons such as the group velocity are determined by the mixing angle between light and matter components and can be controlled by an external coherent field as the pulse propagates. In particular, light pulses can be decelerated and "trapped" in which case their shape and quantum state are mapped onto metastable collective states of matter. Possible applications of this reversible coherent-control technique are discussed.     

Gain leveling using electromagnetically induced transparency

We propose and demonstrate a scheme of gain leveling for erbium-doped fiber amplifier (EDFA) by applying a strong coherent field to a three level amplified system using electromagnetically induced transparency. Due to the effect of this coupling field on the Stark-splitting sublevels, this scheme can be realized a flat gain operating around 1.53 μm.     

Variants of controlling light pulses under conditions of electromagnetically induced transparency with energy degeneracy

The interaction of signal and control fields with an extended medium of two-level atoms with degenerate energy levels is considered in the semiclassical approximation. The effects of recording, storing, and release of signal pulses are studied for several schemes under the conditions of electromagnetically induced transparency. The possibility of inverting the succession of the reconstructed pulses is shown.     

A study of pulse shape in electromagnetically induced transparency based slow light

Slow light of four different pulses are demonstrated and analyzed in cesium vapor based on electromagnetically induced transparency. Each pulse, generated with an identical temporal width, experiences very different slow light effects due to its temporal and spectral distributions simultaneously. Aiming at the applications such as timing, instead of communication, we obtained two optimized ones among the four different shaped pulses. Firstly, the single-exponential pulse is more appropriate to maximize the time delay than other three pulses; secondly, the cosine pulse shows advantage to minimize the distortion (broadening) of the slowed pulse. Finally, using optical filter model, we present a convenient simulation method in theory; moreover, the theoretical results show excellent agreement with experiments.     

Storage and perpendicular retrieving of light pulses in electromagnetically induced transparency media

Storing and perpendicular retrieving of light pulses in electromagnetically induced transparency media is analyzed. A simple obvious analytical solution for the retrieved new field is obtained. It is shown that the generated new pulse time-shape is governed by the initial probe pulse profile while the profile of the new pulse is governed by the time-shape of the initial probe pulse.     

Slow light in coupled-resonator-induced transparency

We performed optical pulse propagation experiments in a system in which two ultrahigh-Q silica microspheres of different diameters were coupled in tandem to a fiber taper to yield coupled-resonator-induced transparency. Nearly Gaussian-shaped optical pulses propagated with a large positive delay of 8.5 ns through a transparent frequency window, without significant attenuation, amplification, or pulse deformation, demonstrating classical analogy of the extremely slow light obtained with electromagnetically induced transparency.