The optical properties of a V-type atomic medium driven by an additional field

Андрій Сіжук, Philip Hemmer

Eugeny Korsunsky, Arno Huss, S. Balushev +3 more

Rasoul Sadighi‐Bonabi, Tayebeh Naseri, Morteza Navadeh-Toupchi

A new scheme to investigate an electromagnetically induced grating in an N-type configuration in the presence of a strong-standing coupling field, additional coherent fields, and microwave driven fields is presented. By considering the coherent population trapping (CPT) condition in a four-level microwave driven N-type atomic system, a novel nonlinear optical storage is obtained via linear absorption vanishing and giant Kerr nonlinearity during light propagation. It is revealed that nonlinear properties in this atomic medium are maximum in the CPT condition, and these nonlinear properties could be affected and modulated by means of a microwave driven field. In this condition high-phase modulated diffraction efficiency is attained. The diffraction pattern is sensitive to variables of the phase and amplitude of microwave field. Consequently one can control the efficiency of different orders of grating more conveniently. The first-order diffraction efficiency of the grating, about 45%, can be obtained by choosing optimum values for the phase and amplitude of the microwave field. It is shown that the phase and modulation grating could be controlled effectively by atomic field-radiation parameters such as the interaction length L of atomic samples and applied field detunings. It has been noted that a novel fast communication device could be obtained at the zero absorption point and on the superluminal light level.

Wenxiao Liu, Xin Wang, Yaqin Chai +2 more

Optical properties of a concentric silver-atomic medium nanoshell are investigated based on the quasi-static and Maxwell-Garnett approximations. We consider the atomic medium as Λ-type three-level atoms driven simultaneously by a coupling field and a probe field. It is shown that the strong coupling between atoms and sphere plasmon of silver core emerges of multiple-mode and ultra narrow-band absorption spectra by controlling the permittivity of the atomic medium. In particular, coherent driving of the coupling field allows us to manipulate surface plasmon resonances, including frequency shift and bandwidth modification. Furthermore, we demonstrate that selective absorption enhancement of different modes can be achieved by tuning the radius of the core and the shell. These absorption properties yield potential applications of the nanoshells as ultracompact tunable nonlinear optical devices.

R. Loudon

Stephan Wielandy