Showing papers on "Electromagnetically induced transparency published in 2012"
TL;DR: This work presents active optical control of metamaterial-induced transparency through active tuning of the dark mode, and opens up the possibility for designing novel chip-scale ultrafast devices that would find utility in optical buffering and terahertz active filtering.
Abstract: Recently reported metamaterial analogues of electromagnetically induced transparency enable a unique route to endow classical optical structures with aspects of quantum optical systems. This method opens up many fascinating prospects on novel optical components, such as slow light units, highly sensitive sensors and nonlinear devices. In particular, optical control of electromagnetically induced transparency in metamaterials promises essential application opportunities in optical networks and terahertz communications. Here we present active optical control of metamaterial-induced transparency through active tuning of the dark mode. By integrating photoconductive silicon into the metamaterial unit cell, a giant switching of the transparency window occurs under excitation of ultrafast optical pulses, allowing for an optically tunable group delay of the terahertz light. This work opens up the possibility for designing novel chip-scale ultrafast devices that would find utility in optical buffering and terahertz active filtering.
998 citations
TL;DR: In this paper, an analog of electromagnetically induced transparency (EIT) in plasmonic systems consisting of multiple cascaded nanodisk resonators, coupled to metal-insulator-metal bus waveguides, was theoretically and numerically investigated.
Abstract: We have theoretically and numerically investigated an analog of electromagnetically induced transparency (EIT) in plasmonic systems consisting of multiple cascaded nanodisk resonators, aperture-side-coupled to metal-insulator-metal bus waveguides. A simplified theoretical model is established to study spectral features in the plasmonic waveguide-resonator systems, and the calculated results are in good agreement with finite-difference time-domain simulations. The main dependent factors of EIT-like spectral response, namely, the resonance detuning, intrinsic Drude loss, and especially cavity-cavity separation, are discussed in detail. Similar to multiple EIT in quantum systems, multiple induced-transparency peaks are found in the areas of strong dispersion generated in our plasmonic system. The group indices and quality factors of transparency resonances with high transmission can reach levels of similar to 35 and similar to 200, respectively. These results pave a way toward dynamic control of light in the nanoscale domain, which can actualize some new devices for fundamental study and applications of plasmonic nanostructures.
296 citations
TL;DR: In this article, a radiating two-oscillator model is proposed to describe both the absorption spectrum and the scattering parameters quantitatively, and the model also predicts metamaterials with a narrow spectral feature in the absorption larger than the background absorption of the radiative element.
Abstract: Several classical analogues of electromagnetically induced transparency in metamaterials have been demonstrated. A simple two-resonator model can describe their absorption spectrum qualitatively, but fails to provide information about the scattering properties-e.g., transmission and group delay. Here we develop an alternative model that rigorously includes the coupling of the radiative resonator to the external electromagnetic fields. This radiating two-oscillator model can describe both the absorption spectrum and the scattering parameters quantitatively. The model also predicts metamaterials with a narrow spectral feature in the absorption larger than the background absorption of the radiative element. This classical analogue of electromagnetically induced absorption is shown to occur when both the dissipative loss of the radiative resonator and the coupling strength are small. These predictions are subsequently demonstrated in experiments.
282 citations
TL;DR: In this article, a review of recent efforts to realize a high efficiency memory for optical pulses using slow and stored light based on electromagnetically induced transparency (EIT) in ensembles of warm atoms in vapor cells is presented.
Abstract: This paper reviews recent efforts to realize a high- efficiency memory for optical pulses using slow and stored light based on electromagnetically induced transparency (EIT) in ensembles of warm atoms in vapor cells. After a brief summary of basic continuous-wave and dynamic EIT properties, studies using weak classical signal pulses in optically dense coherent media are discussed, including optimization strategies for stored light efficiency and pulse-shape control, and modification of EIT and slow/stored light spectral properties due to atomic motion. Quantum memory demonstrations using both single photons and pulses of squeezed light are then reviewed. Finally a brief comparison with other approaches is presented.
267 citations
TL;DR: In this article, the authors observe the excitation and tuning of electromagnetically induced transparency (EIT) by the interference between different excitation pathways of the dark mode in a planar terahertz metamaterial.
Abstract: We observe the excitation and tuning of electromagnetically induced transparency (EIT) by the interference between different excitation pathways of the dark mode in a planar terahertz metamaterial. The EIT unit cell consists of a cut wire as the bright resonator and a pair of split ring resonators (SRRs) as the dark element. The dark mode resonance is excited by both the electric and magnetic fields when the SRR pair translates along the wire without altering the lateral distance between the resonators. The electric and magnetic pathways of exciting the dark mode allows for a giant amplitude modulation of the EIT resonance.
258 citations
06 May 2012
TL;DR: In this article, the authors present the classical analog of electromagnetically induced absorption which is achieved by tuning the coupling phase between a bright and a dark plasmonic resonance in the intermediate regime and thus obtaining constructive interference.
Abstract: We present the classical analog of electromagnetically induced absorption which is achieved by tuning the coupling phase between a bright and a dark plasmonic resonance in the intermediate regime and thus obtaining constructive interference.
224 citations
TL;DR: In this article, a doubly resonant structure can exhibit spectral behavior analogous to electromagnetically induced transparency, as well as superscattering, depending on the excitation.
Abstract: We observe from simulations that a doubly resonant structure can exhibit spectral behavior analogous to electromagnetically induced transparency, as well as superscattering, depending on the excitation. We develop a coupled-mode theory that explains this behavior in terms of the orthogonality of the radiation patterns of the eigenmodes. These results provide insight in the general electromagnetic properties of photonic nanostructures and metamaterials.
185 citations
TL;DR: Electromagnetically induced transparency in the regime of hard X-rays is demonstrated, using the 14.4-kiloelectronvolt nuclear resonance of the Mössbauer isotope iron-57 (a two-level system), to establish the field of nuclear quantum optics.
Abstract: Electromagnetically induced transparency is achieved with hard X-rays in a two-level system, using cooperative emission from ensembles of iron-57 nuclei in a special geometry in a low-finesse cavity. Electromagnetically induced transparency (EIT) is a technique in which quantum interference of multi-level atoms renders an otherwise opaque medium transparent for light of a particular wavelength. With the advent of accelerator-driven light sources, there is growing interest in extending the techniques of such optical quantum control to the X-ray regime. Rohlsberger et al. have now identified an alternative EIT mechanism that enables them to demonstrate the phenomenon in the regime of hard X-rays, using an ensemble of iron-57 nuclei. The authors conclude that this type of EIT and its applications could be transferred to the nuclear regime, opening up the field of nuclear quantum optics. The manipulation of light–matter interactions by quantum control of atomic levels has had a profound impact on optical sciences. Such manipulation has many applications, including nonlinear optics at the few-photon level1,2,3, slow light4,5, lasing without inversion6,7,8 and optical quantum information processing9,10. The critical underlying technique is electromagnetically induced transparency, in which quantum interference between transitions in multilevel atoms11,12,13,14,15 renders an opaque medium transparent near an atomic resonance. With the advent of high-brilliance, accelerator-driven light sources such as storage rings or X-ray lasers, it has become attractive to extend the techniques of optical quantum control to the X-ray regime16,17. Here we demonstrate electromagnetically induced transparency in the regime of hard X-rays, using the 14.4-kiloelectronvolt nuclear resonance of the Mossbauer isotope iron-57 (a two-level system). We exploit cooperative emission from ensembles of the nuclei, which are embedded in a low-finesse cavity and excited by synchrotron radiation. The spatial modulation of the photonic density of states in a cavity mode leads to the coexistence of superradiant and subradiant states of nuclei, respectively located at an antinode and a node of the cavity field. This scheme causes the nuclei to behave as effective three-level systems, with two degenerate levels in the excited state (one of which can be considered metastable). The radiative coupling of the nuclear ensembles by the cavity field establishes the atomic coherence necessary for the cancellation of resonant absorption. Because this technique does not require atomic systems with a metastable level, electromagnetically induced transparency and its applications can be transferred to the regime of nuclear resonances, establishing the field of nuclear quantum optics.
173 citations
TL;DR: A governing equation for spectral asymmetry in electromagnetically induced transparency (EIT) is derived from the key parameters of asymmetry factor - namely dark mode quality factor Q(d), and frequency separation between bright and dark mode Δω(bd) = (ω(b) - ω(d)).
Abstract: In this paper, we derive a governing equation for spectral asymmetry in electromagnetically induced transparency (EIT). From the key parameters of asymmetry factor - namely dark mode quality factor Qd, and frequency separation between bright and dark mode Δωbd = (ωb - ωd) -, a logical pathway for the maximization of EIT asymmetry is identified. By taking the plasmonic metal-insulator-metal (MIM) waveguide as a platform, a plasmon-induced transparency (PIT) structure of tunable frequency separation Δωbd and dark mode quality factor Qd is suggested and analyzed. Compared to previous works on MIM-based plasmon modulators, an order of increase in the performance Fig. (12dB contrast at ~60% throughput) was achieved from the highly asymmetric, narrowband PIT spectra.
168 citations
TL;DR: In this paper, a polarization-independent metamaterial analog of electromagnetically induced transparency (EIT) at microwave frequencies for normal incidence and linearly polarized waves is experimentally and numerically demonstrated.
Abstract: A polarization-independent metamaterial analog of electromagnetically induced transparency (EIT) at microwave frequencies for normal incidence and linearly polarized waves is experimentally and numerically demonstrated. The metamaterial consists of coupled “bright” split-ring resonators (SRRs) and “dark” spiral resonators (SRs) with virtually equal resonance frequencies. Normally incident plane waves with linear polarization strongly couple to the SRR, but are weakly interacting with the SR, regardless of the polarization state. A sharp transmission peak (i.e., the transparency window) with narrow spectral width and slow wave property is observed for the metamaterial at the resonant frequency of both, the bright SRR and the dark SR. The influence of the coupling strength between the SRR and SR on the frequency, width, magnitude, and quality factor of the metamaterial's transparency window is theoretically predicted by a two-particle model, and numerically validated using full-wave electromagnetic simulation. In addition, it is numerically demonstrated that the EIT-like metamaterial can be employed as a refractive-index-based sensor with a sensitivity of 77.25 mm/RIU, which means that the resonance wavelength of the sensor shifts 77.25 mm per unit change of refractive index of the surrounding medium.
167 citations
TL;DR: In this article, the authors theoretically demonstrate the possibility of using nanomechanical systems as single-photon routers using very low pumping powers of a few microwatts and present estimates of vacuum and thermal noise and show that the optimal performance of the singlephoton switch is deteriorated by only a few percent even at temperatures of the order of 20 mK.
Abstract: We theoretically demonstrate the possibility of using nanomechanical systems as single-photon routers. We show how electromagnetically induced transparency in cavity optomechanical systems can be used to produce a switch for a probe field in a single-photon Fock state using very low pumping powers of a few microwatts. We present estimates of vacuum and thermal noise and show that the optimal performance of the single-photon switch is deteriorated by only a few percent even at temperatures of the order of 20 mK.
TL;DR: By utilizing a dielectric-film-coated asymmetric T-shape single slit, comprising two grooves of slightly detuned widths immediately contacting with a single nanoslit, the plasmon-induced transparency was experimentally demonstrated and revealed a response spectrum with nearly the same interference contrast but a much narrower bandwidth.
Abstract: By utilizing a dielectric-film-coated asymmetric T-shape single slit, comprising two grooves of slightly detuned widths immediately contacting with a single nanoslit, the plasmon-induced transparency was experimentally demonstrated. Because of the symmetry breaking in the unit-cell structure, the scattered lights from the two grooves with slightly detuned widths interfere destructively, leading to the plasmon-induced transparency. As a result, a response spectrum with nearly the same interference contrast but a much narrower bandwidth emerges in the unit-cell structure with the footprint of only about 0.9 μm(2), compared with that in the symmetric T-shape single slit. These pronounced features in the structure, such as the increased quality factor, ultracompact size, easy fabrication, and experimental observation, have significant applications in ultracompact plasmonic devices.
TL;DR: Multiple plasmon-induced transparencies are numerically predicted in an ultracompact plAsmonic structure, comprising series of stub resonators side-coupled with a metal-isolator-metal waveguide, using an analytic model and the relative phase analysis based on the scattering matrix theory.
Abstract: Multiple plasmon-induced transparencies are numerically predicted in an ultracompact plasmonic structure, comprising series of stub resonators side-coupled with a metal-isolator-metal waveguide. Because of the phase-coupled effect, electromagnetically induced transparency (EIT)-like spectral response occurs between two adjacent stub resonators with detuned resonant wavelengths. In this approach, multiple EIT-like spectral responses, with bandwidths of the order of several nanometers, are obtained in the plasmonic structure with a small footprint of about 0.6 μm2. An analytic model and the relative phase analysis based on the scattering matrix theory are used to explain this phenomenon.
TL;DR: The proposed compact configuration of a metal-insulator-metal (MIM) waveguide system can avoid the distortion of signal pulse, and thus may find potential applications in plasmonic slow-light systems, especially optical buffers.
Abstract: We have proposed a metal-insulator-metal (MIM) waveguide system, which exhibits a significant slow-light effect, based on a plasmonic analogue of electromagnetically induced transparency (EIT). By appropriately adjusting the distance between the two stubs of a unit cell, a flat band corresponding to nearly constant group index over a broad bandwidth of 8.6 THz can be achieved. The analytical results show that the group velocity dispersion (GVD) parameter can reach zero and normalized delay-bandwidth product (NDBP) is more than 0.522. Finite-Difference Time-Domain (FDTD) simulations show that the incident pulse can be slowed down without distortion owing to the low dispersion. The proposed compact configuration can avoid the distortion of signal pulse, and thus may find potential applications in plasmonic slow-light systems, especially optical buffers.
TL;DR: The theoretical modeling demonstrates that the waveguide-resonator system performs a plasmonic analogue of electromagnetically induced transparency (EIT) in atomic systems, which enables the realization of nanoscale bandpass filters with multiple channels.
Abstract: We have proposed a novel type of bandpass plasmonic filter consisting of metal-insulator-metal bus waveguides coupled with a series of side-coupled cavities and stub waveguides. The theoretical modeling demonstrates that our waveguide-resonator system performs a plasmonic analogue of electromagnetically induced transparency (EIT) in atomic systems, as is confirmed by numerical experiments. The plasmonic EIT-like response enables the realization of nanoscale bandpass filters with multiple channels. Additionally, the operating wavelengths and bandwidths of our filters can be efficiently tuned by adjusting the geometric parameters such as the lengths of stub waveguides and the coupling distances between the cavities and stub waveguides. The ultracompact configurations contribute to the achievement of wavelength division multiplexing systems for optical computing and communications in highly integrated optical circuits.
TL;DR: A completely different approach is to bind electrons into bosonic quasiparticles with a photonic component, which yields dark polaritons analogous to those in atomic systems or optical waveguides, thereby offering new possibilities for electromagnetically induced transparency, room-temperature condensation, and adiabatic photon-to-electron transfer.
Abstract: Tunneling of electrons through a potential barrier is fundamental to chemical reactions, electronic transport in semiconductors and superconductors, magnetism, and devices such as terahertz oscillators. Whereas tunneling is typically controlled by electric fields, a completely different approach is to bind electrons into bosonic quasiparticles with a photonic component. Quasiparticles made of such light-matter microcavity polaritons have recently been demonstrated to Bose-condense into superfluids, whereas spatially separated Coulomb-bound electrons and holes possess strong dipole interactions. We use tunneling polaritons to connect these two realms, producing bosonic quasiparticles with static dipole moments. Our resulting three-state system yields dark polaritons analogous to those in atomic systems or optical waveguides, thereby offering new possibilities for electromagnetically induced transparency, room-temperature condensation, and adiabatic photon-to-electron transfer.
TL;DR: It is seen from simulation results that the synthesis method accurately predicts the center frequency of the multi- band metamaterial, which opens a door to a quick and accurate construction for multi-band slow light metamMaterial.
Abstract: In this paper, a multi-band slow light metamaterial is presented and investigated. The metamaterial unit cell is composed of three cut wires of different sizes and parallel to each other. Two transparency windows induced by two-two overlaps of absorption bands of three cut wires are observed. The multi-band transmission characteristics and the slow light properties of metamaterial are verified by numerical simulation, which is in a good agreement with theoretical predictions. The impacts of structure parameters on transparency windows are also investigated. Simulation results show the spectral properties can be tuned by adjusting structure parameters of metamaterial. The equivalent circuit model and the synthesis method of the multi-band slow light metamaterial are presented. It is seen from simulation results that the synthesis method accurately predicts the center frequency of the multi-band metamaterial, which opens a door to a quick and accurate construction for multi-band slow light metamaterial.
29 Mar 2012
TL;DR: In this paper, the use of the optomechanical nonlinearity as a new way of controlling the velocity of light via engineered photon-phonon interactions was proposed and demonstrated.
Abstract: Controlling the interaction between localized optical and mechanical excitations is now possible following advances in micro- and nano-fabrication techniques. To date, most experimental studies of optomechanics have focused on measurement and control of the mechanical subsystem through its interaction with optics, and have led to the experimental demonstration of dynamical back-action cooling and optical rigidity of the mechanical system. However, the optical response of these systems is also modified in the presence of mechanical interactions, leading to effects such as Electromagnetically Induced Transparency (EIT) and parametric normal-mode splitting, and thus a platform for strongly nonlinear optics. In this talk we propose and demonstrate the use of the optomechanical nonlinearity as a new way of controlling the velocity of light via engineered photon-phonon interactions. Our results demonstrate EIT and tunable optical delays on a nanoscale optomechanical crystal device, fabricated by simply etching holes into a thin film of Silicon. At low temperature (8.7 K), we show an optically-tunable delay of 50 ns with near-unity optical transparency, and superluminal light with a 1.4 μs signal advance. These results, while indicating significant progress towards an integrated quantum optomechanical memory, are also relevant to classical signal processing applications.
TL;DR: In this article, the authors used a quantum molecule where the control laser beam is replaced by the electron tunneling between quantum dots, which can be controlled by an external electric field, opening the possibility to induce transparency and slow light with electric gates.
Abstract: Electromagnetic induced transparency is an optical phenomenon that allows transmission of a laser beam through a dense medium by using a control laser beam. Here, we propose the use of a quantum molecule where the control laser beam is replaced by the electron tunneling between quantum dots, which can be controlled by an external electric field, opening the possibility to induce transparency and slow light with electric gates. Our results show that a transparency window appears if the tunneling strength ${T}_{e}$ and the decay rate of direct exciton ${\ensuremath{\Gamma}}_{1}$ obey the condition ${T}_{e}/{\ensuremath{\Gamma}}_{1}\ensuremath{\le}0.5$.
TL;DR: It is shown that it is possible to image individual Rydberg atoms with enhanced sensitivity and high resolution despite photon-shot noise and atomic density fluctuations, and this new imaging scheme could be extended to other impurities such as ions.
Abstract: We propose a new all-optical method to image individual Rydberg atoms embedded within dense gases of ground state atoms. The scheme exploits interaction-induced shifts on highly polarizable excited states of probe atoms, which can be spatially resolved via an electromagnetically induced transparency resonance. Using a realistic model, we show that it is possible to image individual Rydberg atoms with enhanced sensitivity and high resolution despite photon-shot noise and atomic density fluctuations. This new imaging scheme could be extended to other impurities such as ions, and is ideally suited to equilibrium and dynamical studies of complex many-body phenomena involving strongly interacting particles. As an example we study blockade effects and correlations in the distribution of Rydberg atoms optically excited from a dense gas.
TL;DR: Using coherent population trapping, this work generates a coherent superposition of the singlet and triplet states of an optically active quantum dot molecule, and shows that the corresponding T2* may exceed 200 ns.
Abstract: In semiconductors, the ${T}_{2}^{*}$ coherence time of a single confined spin is limited either by the fluctuating magnetic environment (via the hyperfine interaction), or by charge fluctuations (via the spin-orbit interaction). We demonstrate that both limitations can be overcome simultaneously by using two exchange-coupled electron spins that realize a single decoherence-avoiding qubit. Using coherent population trapping, we generate a coherent superposition of the singlet and triplet states of an optically active quantum dot molecule, and show that the corresponding ${T}_{2}^{*}$ may exceed 200 ns.
TL;DR: Wang and Clerk as discussed by the authors proposed a hybrid state transfer scheme that combines the advantages of the dark mode and the double-swap scheme to improve the fidelity of state transfer between two electromagnetic cavities coupled to a common mechanical resonator.
Abstract: In a recent publication (Wang and Clerk 2012 Phys. Rev. Lett. 108 153603), we demonstrated that one can use interference to significantly increase the fidelity of state transfer between two electromagnetic cavities coupled to a common mechanical resonator over a naive sequential-transfer scheme based on two swap operations. This involved making use of a delocalized electromagnetic mode which is decoupled from the mechanical resonator, a so-called ‘mechanically dark’ mode. Here, we demonstrate the existence of a new ‘hybrid’ state transfer scheme that incorporates the best elements of the dark-mode scheme (protection against mechanical dissipation) and the double-swap scheme (fast operation time). Importantly, this new scheme also does not require the mechanical resonator to be prepared initially in its ground state. We also provide additional details of the previously described interference-enhanced transfer schemes, and provide an enhanced discussion of how the interference physics here is intimately related to the optomechanical analogue of electromagnetically induced transparency. We also compare the various transfer schemes over a wide range of relevant experimental parameters, producing a ‘phase diagram’ showing the optimal transfer scheme for different points in parameter space.
TL;DR: The implementation of electromagnetically induced transparency (EIT) in a cold Rydberg gas provides an attractive route towards strong photon-photon interactions and fully deterministic all-optical quantum information processing as discussed by the authors.
Abstract: The implementation of electromagnetically induced transparency (EIT) in a cold Rydberg gas provides an attractive route towards strong photon--photon interactions and fully deterministic all-optical quantum information processing. In this brief review we discuss the underlying principles of how large single photon non-linearities are achieved in this system and describe experimental progress to date.
TL;DR: In this article, the authors analyzed the hybrid absorptive-dispersive optical bistability behavior in an open Λ-type three-level atomic system by using a microwave field to drive the hyperfine transition between two lower states, along with the consideration of incoherent pumping and spontaneously generated coherence.
Abstract: We analyze the hybrid absorptive-dispersive optical bistability (OB) behavior in an open Λ-type three-level atomic system by using a microwave field to drive the hyperfine transition between two lower states, along with the consideration of incoherent pumping and spontaneously generated coherence. Different from the closed system, we show that the bistable threshold intensity and related hysteresis loop can be controlled by adjusting the ratio between atomic injection and exit rates. More interestingly, the appearance and disappearance of OB can be transformed mutually by varying the relative phase of three coherent fields under the condition of a strong spontaneously generated coherence. The manipulation of OB behavior through the intensity of the microwave field and the atomic cooperation parameter is also analyzed.
TL;DR: In this article, a three-dimensional photonic metamaterial consisting of an array of erected U-shape plasmonic gold nanostructures that exhibits the PIT phenomenon with magnetic dipolar interaction between magnetic meta molecules is presented.
Abstract: In a laser-driven atomic quantum system, a continuous state couples to a discrete state resulting in quantum interference that provides a transmission peak within a broad absorption profile the so-called electromagnetically induced transparency (EIT). In the field of plasmonic metamaterials, the subwavelength metallic structures play a role similar to atoms in nature. The interference of their near-field coupling at plasmonic resonance leads to a plasmon induced transparency (PIT) that is analogous to the EIT of atomic systems. A sensitive control of the PIT is crucial to a range of potential applications such as slowing light and biosensor. So far, the PIT phenomena often arise from the electric resonance, such as an electric dipole state coupled to an electric quadrupole state. Here we report the first three-dimensional photonic metamaterial consisting of an array of erected U-shape plasmonic gold nanostructures that exhibits PIT phenomenon with magnetic dipolar interaction between magnetic meta molecules. We further demonstrate using a numerical simulation that the coupling between the different excited pathways at an intermediate resonant wavelength allows for a pi phase shift resulting in a destructive interference. A classical RLC circuit was also proposed to explain the coupling effects between the bright and dark modes of EIT-like electromagnetic spectra. This work paves a promising approach to achieve magnetic plasmon devices.
TL;DR: It is found that the system supports three excitonic-induced transparencies in the energy absorption spectrum of the metallic nanoparticle and it is shown that the photonic crystal allows us to manipulate the frequencies of such excitonia and the amplitude of theEnergy absorption rate.
Abstract: We study the variation of the energy absorption rate in a hybrid semiconductor quantum dot–metallic nanoparticle system doped in a photonic crystal. The quantum dot is taken as a three-level V-configuration system and is driven by two applied fields (probe and control). We consider that one of the excitonic resonance frequencies is near to the plasmonic resonance frequency of the metallic nanoparticle, and is driven by the probe field. The other excitonic resonance frequency is far from both the plasmonic resonance frequency and the photonic bandgap edge, and is driven by the control field. In the absence of the photonic crystal we found that the system supports three excitonic-induced transparencies in the energy absorption spectrum of the metallic nanoparticle. We show that the photonic crystal allows us to manipulate the frequencies of such excitonic-induced transparencies and the amplitude of the energy absorption rate.
TL;DR: An all-optical analog to electromagnetically induced transparency (EIT) on chip is experimentally demonstrated using coupled high-Q silica microtoroid cavities with Q-factors above 10(6) to control the transmission spectrum.
Abstract: We experimentally demonstrate an all-optical analog to electromagnetically induced transparency (EIT) on chip using coupled high-Q silica microtoroid cavities with Q-factors above 106. The transmission spectrum of the all-optical analog to EIT is precisely controlled by tuning the distance between the two microtoroids, as well as the detunings of the resonance frequencies of the two cavities.
TL;DR: The zero magnetic field along the longitudinal axis allows the cold atoms maintain a long ground-state coherence time without switching off the MOT magnetic field, which makes it possible to operate the MOT at a high repetition rate and a high duty cycle.
Abstract: We describe the apparatus of a dark-line two-dimensional (2D) magneto-optical trap (MOT) of 85Rb cold atoms with high optical depth (OD). Different from the conventional configuration, two (of three) pairs of trapping laser beams in our 2D MOT setup do not follow the symmetry axes of the quadrupole magnetic field: they are aligned with 45° angles to the longitudinal axis. Two orthogonal repumping laser beams have a dark-line volume in the longitudinal axis at their cross over. With a total trapping laser power of 40 mW and repumping laser power of 18 mW, we obtain an atomic OD up to 160 in an electromagnetically induced transparency (EIT) scheme, which corresponds to an atomic-density-length product NL = 2.05 × 1015 m−2. In a closed two-state system, the OD can become as large as more than 600. Our 2D MOT configuration allows full optical access of the atoms in its longitudinal direction without interfering with the trapping and repumping laser beams spatially. Moreover, the zero magnetic field along the ...
TL;DR: A plasmonic waveguide system based on side-coupled complementary split-ring resonators (CSRR), which exhibits electromagnetically induced transparency (EIT)-like transmission is investigated, verified by simulation results of finite difference time domain method.
Abstract: We investigate a plasmonic waveguide system based on side-coupled complementary split-ring resonators (CSRR), which exhibits electromagnetically induced transparency (EIT)-like transmission. LC resonance model is utilized to explain the electromagnetic responses of CSRR, which is verified by simulation results of finite difference time domain method. The electromagnetic responses of CSRR can be flexible handled by changing the asymmetry degree of the structure and the width of the metallic baffles. Cascaded CSRRs also have been studied to obtain EIT-like transmission at visible and near-infrared region, simultaneously.
TL;DR: It is demonstrated that electromagnetically induced transparency in a four-level cascade system where the upper level is a Rydberg state can be enhanced due to the compensation of Doppler shifts with AC Stark shifts.
Abstract: We demonstrate electromagnetically induced transparency in a four-level cascade system where the upper level is a Rydberg state. The observed spectral features are sub-Doppler and can be enhanced due to the compensation of Doppler shifts with AC Stark shifts. A theoretical description of the system is developed that agrees well with the experimental results, and an expression for the optimum parameters is derived.