Super-collimation and negative refraction in hyperbolic Van der Waals superlattices

Kandammathe Valiyaveedu Sreekanth; Robert E. Simpson

doi:10.1016/j.optcom.2019.02.020

Super-collimation and negative refraction in hyperbolic Van der Waals superlattices

Kandammathe Valiyaveedu Sreekanth^*, Robert E. Simpson

^*Corresponding author for this work

Electronic, Electrical and Systems Engineering

Research output: Contribution to journal › Article › peer-review

6 Citations (Scopus)

Abstract

In this paper, we investigate supercollimation and negative group refraction properties of Van der Waals crystals. Van der Waals crystals, such as Bi ₂ Se ₃ , show both type I and type II hyperbolic dispersion at terahertz (THz) frequencies. An all angle negative group index of refraction is observed at frequencies that exhibit type I hyperbolic dispersion. However, a negative group index of refraction is observed at higher angles in the type II spectral region. The supercollimation effect is achieved at the inversion point of type II and the Reststrahlen band, where the resonance cone angle is close to zero. We further show broadband tunable hyperbolic dispersion from THz to mid infrared frequencies and a widening of the negative group index spectral band using topological insulator–dielectric insulator based superlattice structures.

Original language	English
Pages (from-to)	150-154
Number of pages	5
Journal	Optics Communications
Volume	440
DOIs	https://doi.org/10.1016/j.optcom.2019.02.020
Publication status	Published - 1 Jun 2019

Bibliographical note

Funding Information:
This work was supported by the Singapore ministry of education Tier 2 project number T2MOE1713.

Funding Information:
This work was supported by the Singapore ministry of education Tier 2 project number T2MOE1713 .

Publisher Copyright:
© 2019 Elsevier B.V.

Keywords

Hyperbolic metamaterials
Negative refraction
THz frequencies
Topological insulators
Van der Waals crystals

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Atomic and Molecular Physics, and Optics
Physical and Theoretical Chemistry
Electrical and Electronic Engineering

Access to Document

10.1016/j.optcom.2019.02.020

Cite this

@article{a73ce68ac8034af5b5f9c9a1967a4bf0,

title = "Super-collimation and negative refraction in hyperbolic Van der Waals superlattices",

abstract = " In this paper, we investigate supercollimation and negative group refraction properties of Van der Waals crystals. Van der Waals crystals, such as Bi 2 Se 3 , show both type I and type II hyperbolic dispersion at terahertz (THz) frequencies. An all angle negative group index of refraction is observed at frequencies that exhibit type I hyperbolic dispersion. However, a negative group index of refraction is observed at higher angles in the type II spectral region. The supercollimation effect is achieved at the inversion point of type II and the Reststrahlen band, where the resonance cone angle is close to zero. We further show broadband tunable hyperbolic dispersion from THz to mid infrared frequencies and a widening of the negative group index spectral band using topological insulator–dielectric insulator based superlattice structures.",

keywords = "Hyperbolic metamaterials, Negative refraction, THz frequencies, Topological insulators, Van der Waals crystals",

author = "Sreekanth, {Kandammathe Valiyaveedu} and Simpson, {Robert E.}",

note = "Funding Information: This work was supported by the Singapore ministry of education Tier 2 project number T2MOE1713. Funding Information: This work was supported by the Singapore ministry of education Tier 2 project number T2MOE1713 . Publisher Copyright: {\textcopyright} 2019 Elsevier B.V.",

year = "2019",

month = jun,

day = "1",

doi = "10.1016/j.optcom.2019.02.020",

language = "English",

volume = "440",

pages = "150--154",

journal = "Optics Communications",

issn = "0030-4018",

publisher = "Elsevier",

}

TY - JOUR

T1 - Super-collimation and negative refraction in hyperbolic Van der Waals superlattices

AU - Sreekanth, Kandammathe Valiyaveedu

AU - Simpson, Robert E.

N1 - Funding Information: This work was supported by the Singapore ministry of education Tier 2 project number T2MOE1713. Funding Information: This work was supported by the Singapore ministry of education Tier 2 project number T2MOE1713 . Publisher Copyright: © 2019 Elsevier B.V.

PY - 2019/6/1

Y1 - 2019/6/1

N2 - In this paper, we investigate supercollimation and negative group refraction properties of Van der Waals crystals. Van der Waals crystals, such as Bi 2 Se 3 , show both type I and type II hyperbolic dispersion at terahertz (THz) frequencies. An all angle negative group index of refraction is observed at frequencies that exhibit type I hyperbolic dispersion. However, a negative group index of refraction is observed at higher angles in the type II spectral region. The supercollimation effect is achieved at the inversion point of type II and the Reststrahlen band, where the resonance cone angle is close to zero. We further show broadband tunable hyperbolic dispersion from THz to mid infrared frequencies and a widening of the negative group index spectral band using topological insulator–dielectric insulator based superlattice structures.

AB - In this paper, we investigate supercollimation and negative group refraction properties of Van der Waals crystals. Van der Waals crystals, such as Bi 2 Se 3 , show both type I and type II hyperbolic dispersion at terahertz (THz) frequencies. An all angle negative group index of refraction is observed at frequencies that exhibit type I hyperbolic dispersion. However, a negative group index of refraction is observed at higher angles in the type II spectral region. The supercollimation effect is achieved at the inversion point of type II and the Reststrahlen band, where the resonance cone angle is close to zero. We further show broadband tunable hyperbolic dispersion from THz to mid infrared frequencies and a widening of the negative group index spectral band using topological insulator–dielectric insulator based superlattice structures.

KW - Hyperbolic metamaterials

KW - Negative refraction

KW - THz frequencies

KW - Topological insulators

KW - Van der Waals crystals

UR - http://www.scopus.com/inward/record.url?scp=85061636282&partnerID=8YFLogxK

U2 - 10.1016/j.optcom.2019.02.020

DO - 10.1016/j.optcom.2019.02.020

M3 - Article

AN - SCOPUS:85061636282

SN - 0030-4018

VL - 440

SP - 150

EP - 154

JO - Optics Communications

JF - Optics Communications

ER -

Super-collimation and negative refraction in hyperbolic Van der Waals superlattices

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

Access to Document

Fingerprint

Cite this