DCMPMS Seminars

Electromagnetically induced transparency in terahertz metamaterials

by Ms. Koijam Monika Devi (Research Scholar Department of Physics, Indian Institute of Technology, Guwahati)

Thursday, May 23, 2019 from to (Asia/Kolkata)
at AG69
Description
The concept of attaining a controlled optical response of a material lies at the core of many of the advances in the field of optics. In the subwavelength regime, an effective control of the interaction between light and matter has become possible with the advent of metamaterials (MMs) and plasmonics. Recently, MMs have been used to explore quantum phenomenon such as electromagnetically induced transparency (EIT), in which a medium opaque to a resonant field is rendered transparent by applying another field of similar resonant frequency. In MMs, the EIT effect usually occurs as a result of interference between the bright and the dark modes. The destructive interference of these modes induces a narrow transparency region in an otherwise absorptive spectrum. Within this region, the incident radiation gets transmitted through the medium and the dispersive properties of the medium gets strongly modified. The different aspects of the EIT phenomenon such as: tunable transparency window, steep dispersion and enhanced nonlinearity can be explored in the context of terahertz MMs. In the talk, I would largely focus on the tunable transparency aspect of the EIT effect in terahertz MMs. For instance, the tunable transparency window achieved in the plasmon induced transparency (PIT) effect in the terahertz MM structures can be significant in designing devices for a range of applications in the broadband as well as narrowband regime. A polarization independent PIT behavior would enhance the efficiency of the devices and can lead to the development of devices for polarization independent broadband, slow light and sensing applications. The dynamic tunability of the graphene based terahertz MM can be significant in the realization of frequency agile actively tunable devices. The double tunable transparency region of the dual-band EIT effect can be significant in the development of multiband slow light devices. Also, the narrow region of absorption associated with the dual-band EIT effect could be exploited for the development of narrowband absorbers. In view of the recent trends in this area of research, there are endless possibilities in exploring the potential applications of the EIT effect in terahertz MMs.