Electromagnetically induced transparency and electromagnetically induced absorption in Y-type system

Abstract

The propagation of a probe field through a four-level Y-type atomic system is described in the presence of two additional coherent radiation fields, namely, the control field and the coupling field. An expression for the probe response is derived analytically from the optical Bloch equations under steady state condition to study the absorptive properties of the system under probe field propagation through an ensemble of stationary atoms as well as in a Doppler broadened atomic vapor medium. The most striking result is the conversion of electromagnetically induced transparency (EIT) into electromagnetically induced absorption (EIA) as we start switching from weak probe regime to strong probe regime. The dependence of this conversion on residual Doppler averaging due to wavelength mismatch is also shown by choosing the coupling transition as a Rydberg transition.

Graphene‐based tunable terahertz electromagnetically induced transparency using metamaterial structure

“…[4][5][6][7][8][9][10][11][12][13][14] Moreover, a classical method was proposed to realize the analogue EIT phenomenon through the coupling between the resonators of bright and dark modes, and the strength of the analogue EIT effect could be adjusted by controlling the near field coupling and resonant loss of the two modes. 15,16 However, for most previous metamaterialbased EIT studies, the operating frequency of the transparent window can be passively adjusted, that is, the frequency of the transparent window can only be tuned by changing the internal EIT-like structural parameters, such as the geometric size and coupling distance, which severely limits the application of EIT-like in tunable slow light devices. [17][18][19][20] It is highly desirable that the EIT-like effect can be actively modulated.…”

“…Recently, metamaterials have received tremendous attention since they can manipulate the interaction between light and matter in artificial structures, making it possible to realize the analogue EIT effect in classical optical systems 4–14 . Moreover, a classical method was proposed to realize the analogue EIT phenomenon through the coupling between the resonators of bright and dark modes, and the strength of the analogue EIT effect could be adjusted by controlling the near field coupling and resonant loss of the two modes 15,16 . However, for most previous metamaterial‐based EIT studies, the operating frequency of the transparent window can be passively adjusted, that is, the frequency of the transparent window can only be tuned by changing the internal EIT‐like structural parameters, such as the geometric size and coupling distance, which severely limits the application of EIT‐like in tunable slow light devices 17–20 .…”

Manipulation of transmission properties of a ladder-four-level Rydberg atomic system

“…三能级梯型里德伯原子模型进行改进, 讨论了三能 级里德伯冷原子系统的相干效应, 结果表明在低温 下多普勒展宽会削弱探测光的的非经典性质 [34] ; 利用数值计算方法, 讨论了多普勒效应对分子磁体 介质中透射光栅的影响 [35,36] . 在四能级Y型系统 中, 当探测场的拉比频率增加时, 探测场的电磁诱 导透明会转化为电磁诱导吸收 [37] ; 英国和美国的 小组在四能级梯型里德伯原子系统中观察到了电 磁诱导透明, 探测光谱呈现亚多普勒特征, 由于交 流斯塔克位移补偿了多普勒频移, 可以实现光谱增 强 [38] .…”