Controlled processing of signal stored in metamaterial with tripod structure

In the present paper we have discussed in detail electromagnetically induced transparency and signal storing in the case of one signal pulses propagating in a classical electric medium resembling this of four-level atoms in the tripod configuration. Our theoretical results confirm recently observed dependence of transparency windows position on coupling parameters. In the process of storing the pulse energy is confined inside the metamaterial as electric charge oscillations and after required time it is possible to switch the control fields on again and to release the trapped signal. By manipulating the driving fields one can thus control the parameters of the released signal and even to divide it on demand into arbitrary parts.Comment: 12 pages, 7 figure

Combined complex Doppler and Cherenkov effect in left-handed metamaterials

We derive the formula of the complex Doppler shift in a two-dimensional, dispersive metamaterial and we show that a moving, monochromatic radiation source generates multiple frequency modes. The role of the group velocity is stressed and the Doppler shifted radiation field exhibits features of the Cherenkov effect. The presented theory is also applicable to the case of a moving, nonoscillating charge and explains many peculiar characteristics of the Cherenkov radiation in lefthanded metamaterials such as the backward direction of power emission, the constant radiation angle and the lack of velocity threshold.Comment: 11 pages, 7 figure

Frequency shifts of radiating particle moving in EIT metamaterial

Nowadays, there is considerable interest in metamaterials which realize the electromagnetically induced transparency in a classical system. We consider the frequency shifts of particle moving in metamaterials exhibiting electromagnetically induced transparency effect. The dramatic change of the material dispersion due to the EIT influences the conditions for signal propagation in the medium and has a significant impact on the Doppler effect, possibly leading to the optical control over this phenomenon. The dependence of the Doppler shift to the source frequency and velocity and radiation spectra on external parameters is examined. It was found that for source frequencies fitting transparency window for particular range of source velocities cutoffs appear, i.e. the radiation is not emitted. Our theoretical findings are proved analytically and confirmed by numerical simulations based on finite-difference time-domain method.Comment: 10 pages, 12 figure

Ultraslow long-living plasmons with electromagnetically induced transparency

We analytically examine propagation of surface plasmon polaritons (SPPs) at a thin metallic film between glass substrate and electromagnetically-induced-transparency (EIT) medium. High-precision and high-resolution in frequency domain provided by EIT paves the way towards plasmonic group velocities reduction even by $4$ orders of magnitude and corresponding lifetime enhancement of SPPs up to microseconds.Comment: 5 pages, 5 figure

Excitonic Spectra of Wide Parabolic Quantum Wells

The optical properties of wide Quantum Wells are considered, taking into account the screened electron-hole interaction potential and parabolic confinement potentials, different for the electrons and for the holes. The role of the interaction potential which mixes the energy states according to different quantum numbers is stressed. The results obtained by our method are in agreement with the observed spectra and give the possibility to the assessment of the resonances.Comment: 13 pages, 7 figures typos correcte

Electrooptical Properties of Rydberg Excitons

We show how to compute the electrooptical functions (absorption, reflection, and transmission) when Rydberg Excitons appear, including the effect of the coherence between the electron-hole pair and the electromagnetic field. With the use of Real Density Matrix Approach numerical calculations applied for Cu$_2$0 crystal are performed. We also examine in detail and explain the dependence of the resonance displacement on the state number and applied electric field strength. We report a good agreement with recently published experimental data.Comment: 14 pages, 10 figures, updated and cleared u

Optical Properties of Rydberg Excitons and Polaritons

We show how to compute the optical functions when Rydberg Excitons appear, including the effect of the coherence between the electron-hole pair and the electromagnetic field. We use the Real Density Matrix Approach (RDMA), which, combined with Green's function method, enables one to derive analytical expressions for the optical functions. Choosing the susceptibility, we performed numerical calculations appropriate to a Cu$_2$0 crystal. The effect of the coherence is displayed in the line shape. We also examine in details and explain the dependence of the oscillator strength and the resonance placement on the state number. We report a good agreement with recently published experimental data.Comment: 16 pages, 5 figures, submitted to PR

Electro-optical properties of Cu2_2O in the regime of Franz-Keldysh oscillations

We present the analytical method enables one to compute the optical functions i.e., reflectivity, transmission and absorption including the excitonic effects for a semiconductor crystal exposed to a uniform electric field for energy region above the gap, for external field suitable to appearance of Franz-Keldysh (FK) oscillations. Our approach intrinsically takes into account the coherence between the carriers and the electromagnetic field. We quantitatively describe the amplitudes and periodicity of FK modulations and the influence of Rydberg excitons on FK effect is also taking into account. Our analytical findings are illustrated numerically for $P$ excitons in Cu$_2$O crystal.Comment: 12 pages, 10 figure

Nonlinear Optical Properties and Self-Kerr Effect of Rydberg Excitons in Cu2_2O

We show how to compute the nonlinear optical functions (absorption, reflection, and transmission) for a medium with Rydberg excitons, including the effect of the coherence between the electron-hole pair and the electromagnetic field. Using the Real Density Matrix Approach the analytical expressions for nonlinear optical functions are obtained and numerical calculations for Cu$_2$0 crystal are performed. We report a good agreement with recently published experimental data. Propagation of the electromagnetic waves in Rydberg excitons media with nonliner effect is also discussed and the possibility of obtainig self-phase modulation due to Kerr nonlinearity is investigated.Comment: 8 pages, 6 figure

Tunable Rydberg excitons maser

We propose a solid state maser based on Cu2O, where ensemble of highly excited Rydberg exciton states serves as a gain medium. We show that the system is highly tunable with external electric field, allowing for a wide range of emission frequencies. Numerical simulations of system dynamics are performed to optimize the conditions for efficient masing and estimate the emission power.Comment: 4 pages, 5 figure