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Electromagnetically Induced Transparency in Semiconductor Quantum Wells
Published in Kong-Thon Tsen, and Nanostructures, 2018
Electromagnetically induced transparency (EIT) is a process whereby destructive quantum interference causes an otherwise absorbing optical transition to become nearly transparent. This section analyzes, theoretically, EIT processes in an atomiclike three-level system in a transient regime. There are three different configurations for three-level systems: (1) Λ-type, (2) cascaded-type, and (3) V-type, as shown in Figure 8.1. This section focuses on the Λ-system with states |a〉, |b), and |e〉, where the |a〉 ↔ |e〉 and |b〉 ↔ |e〉 are dipole transitions coupled by electric fields εa and εb, respectively, as shown in Figure 8.2. The |a〉↔|b〉 transition is dipole-forbidden.
Picometer Detection by Adaptive Holographic Interferometry
Published in Klaus D. Sattler, Fundamentals of PICOSCIENCE, 2013
Electromagnetically induced transparency (EIT) (Harris 1997) is a phenomenon in which absorption on an atomic transition and concomitant losses due to spontaneous emission are eliminated via destructive interference between alternative routes from a ground atomic state to an excited atomic state. In atoms such as rubidium, this can be achieved by employing transitions from two hyperfine ground states to a single excited state, one transition of which is driven by a control (laser) field. This control field "dresses" the excited state and thereby determines the optical response of the atomic medium to another, weaker probe field, which drives the other transition. Since the elimination of atomic absorption can occur even for fields in resonance with the atomic transition, the nonlinear response can be enormous, or in other words, giant optical nonlinearities are possible (Fleischhauer et al. 2005).
Electrical Impedance Tomography Using Evolutionary Computing: A Review
Published in D. P. Acharjya, V. Santhi, Bio-Inspired Computing for Image and Video Processing, 2018
Wellington Pinheiro dos Santos, Ricardo Emmanuel de Souza, Reiga Ramalho Ribeiro, Allan Rivalles Souza Feitosa, Valter Augusto de Freitas Barbosa, Victor Luiz Bezerra Arajo da Silva, David Edson Ribeiro, Rafaela Covello de Freitas
Electrical impedance tomography (EIT) is a non-invasive set of techniques of image reconstruction, which can be used to obtain estimated images of electrical conductivity or permittivity in the inside of a section of any body/object through electrical quantity measured in its surface [11,18,51]. Getting images through EIT techniques consists of solving an inverse, ill-posed, and ill-conditioned problem, where it is observed that the distribution of electrical conductivity inside a body/object is estimated, given the electrical current of excitement and the electrical potentials measured in its surface [4,53]. Currently, EIT has applications in several areas, e.g., geophysics, medicine, and industry.
Polarization angle tailored multitasking metasturcure: electromagnetically induced transparency, electromagnetically induced absorption, linear-to-circular polarization conversion
Published in Waves in Random and Complex Media, 2023
You Lv, Fang-Yao Fang, Yu-Jing Yin, Hai-Feng Zhang
Metastructure (MS), which can be acted as multifunctional metamaterials, has attracted a lot of attention due to its ability to generate electromagnetic responses that are unattainable in nature [1]. Electromagnetically induced transparency (EIT), arising from the destructive interference between different atomic leap channels, is an inherent quantum interference in three-atom systems [2]. In recent years, EIT has been extensively researched, enabling opaque media to be narrowly transparent and accompanied by intense dispersion and strong slow light effects [3,4]. EIT in most quantum systems requires incredibly demanding experimental circumstances, including extremely low temperatures and super-bumps of laser light, which basically cannot be implemented and applied to physical devices. However, in 2008, Zhang et al. successfully introduced the EIT effect to electromagnetic MSs [5]. Since then, due to its unique properties, EIT has been greatly exploited in slow-light devices [3,4], optical switches [6,7], photon storage, and nonlinear self-enhancement [8–10]. EIT is mainly generated by [11–13] bright-dark mode coupling alternately, bright-bright mode coupling [14,15]. The former is mainly formed by destructive interference, while the formation is due to the influence of weak hybridization on bright modes.
Achieving polarization control by utilizing electromagnetically induced transparency based on metasurface
Published in Waves in Random and Complex Media, 2022
Cheng-Jing Gao, Yuan-Zhe Sun, Han-Qing Dong, Hai-Feng Zhang
Electromagnetically induced transparency (EIT) is a quantum destructive interference in three or multi-level atomic systems, leading to a steep and transparent transmission window in the original opaque medium [1]. In 1991, Boiler et al. [2] first found such an EIT phenomenon in the three-level atomic system. Subsequently, researchers found that it can greatly aggravate the dispersion change in opaque media, which can dramatically retard the propagation of the incident light and display a large group index (GI). And the performance of the EIT exhibits an apparent group delay (GD), which renders a slow-light effect [3,4]. Furthermore, the EIT effect with the transparent and highly dispersive features can offer an approach to the high-quality-factor and low-loss resonances [5], which can be essential for achieving low-loss slow-light devices [6], filters [7], sensors [8], and enhancing nonlinear interactions [9]. Nevertheless, realizing the EIT phenomenon needs stern and fastidious experimental conditions in atomic systems, such as a strong laser and a lower temperature, which hinder wide applications in practical engineering and the miniaturization and integration of devices related to the EIT. Correspondingly, with the advent and continuous researches of metamaterials, this dilemma can be well broken.
High transmission of negative permittivity materials based on strong magnetic field coupling
Published in Journal of Microwave Power and Electromagnetic Energy, 2018
Linyan Guo, Helin Yang, Qisheng Zhang, Deng Ming
Metamaterials with exotic electromagnetic properties have attracted a lot of interest in recent years (Smith et al. 2004; Pfeiffer et al. 2014; Guo et al. 2014), including induce high transmittance of electromagnetic waves through opaque materials (Luk’yanchuk et al. 2010; Yu et al. 2015; Mun et al. 2016). Previously, there are many ways to achieve high transmittance, such as the excitation of surface plasmons (SP), Fabry-Perot (FP) and electromagnetically induced transparency (EIT) (Flynn et al. 2010; Liu et al. 2014; Pitchappa et al. 2016). By using prism couplers, SP can induce high transmission through an opaque metallic film (Papanikolaou 2007). In addition, FP resonance can also induce high transmission through metallic film with thin slits (Yang & Sambles 2002; Hibbins et al. 2006). There is also another way to achieve high transmission using the plasmonic analog of the EIT in atomic system (Meng et al. 2011; Tiburcio et al. 2015). EIT is a coherent process observed in atomic media, in which an opaque material is rendered to be transparent in a narrow spectral region within a broadband absorption band. The analog of EIT in metamaterials has received growing attentions, because of the metamaterials’ versatilities and attractive advantages. An experimental setup for EIT able to manufacture microcells, suitable for optical fiber communications technology has been achieved by Tiburcio et al. (2015).