The determination of the relative permittivity of periodic stratified media based on the iterative time-reversal method

In this paper, we present a new method to determine the relative permittivity of periodic stratified media using the iterative time-reversal method. Based on transmission line theory, the focal peak value of iterative time-reversal electro- magnetic waves, which contain information about the periodic stratified medium, is computed in pulse-echo mode. Using the relationship between the focal peak value and the relative permittivity of the periodic stratified medium, the relative permittivity can be obtained by measuring the focal peak value. Numerical simulations are conducted, and the results demonstrate the feasibility of the proposed approach to the measurement of the relative permittivity of a periodic stratified medium.

Probe frequency- and field intensity-sensitive coherent control effects in an EIT-based periodic layered medium

A periodic layered medium, with unit cells consisting of a dielectric and an electromagnetically-induced transparency （EIT）-based atomic vapor, is designed for light propagation manipulation. Considering that a destructive quantum interference relevant to a two-photon resonance emerges in EIT-based atoms interacting with both control and probe fields, an EIT-based periodic layered medium exhibits a flexible frequency-sensitive optical response, where a very small variation in the probe frequency can lead to a drastic variation in reflectance and transmittance. The present EIT-based periodic layered structure can result in controllable optical processes that depend sensitively on the external control field. The tunable and sensitive optical response induced by the quantum interference of a multi-level atomic system can be applied in the fabrication of new photonic and quantum optical devices. This material will also open a good perspective for the application of such designs in several new fields, including photonic microcircuits or integrated optical circuits.

The Underground Water Level Simulation in Imamzadeh Jafar Plateau by the Use of Mudflow Software

The most secure method in providing water in the dry and semi-dry regions is the use of underground water sources and due to over consumption of water aquifers capacities, most of fields and specially Imamzadeh Jafar are faced with negative performance and balance, which threatens the land subsiding. The plateau with the annual raining of 438 millimeters has 169 deep and semi-deep wells with annual 36.68 million consumption and this issue has increased the research signification, in order to protect and relive the required water aquifers, there is a need to predict the underground water level accurately in different condition. In this research, by the use of balance equation and modflow software in Imamzadeh Jafar, water aquifer was analyzed within seven scenario. The underground water level evaluation for the short run periods for 2 years and middle term of 4 years and 12 years of long term was performed;and the results showed that the performance and balance of the plateau was increased due to increase of water consumption compared to the water aquifer quantity in the region that was negative. To the point that the 1, 3, 4, 5, 7 scenarios (minimum 0.17 and maximum -11.34) and 2, 6 scenarios in different timely periods show that the underground water saving volume is positive (minimum 3.64 and maximum 19.83).