Cavity quantum electrodynamic analysis of spasing in nanospherical dimers

Tharindu Warnakula, Sarath D. Gunapala, Mark I. Stockman, Malin Premaratne

Research output: Contribution to journalArticleResearchpeer-review

Abstract

We present a detailed cavity quantum electrodynamic model of a nanospherical dimer and use it to analyze bright hybrid spasing modes there. Using an approximate numerical scheme, we model the complete spasing system as an open quantum system under the Lindblad dissipator formalism. We show that while in general the longitudinal dimer setups display higher intensity spasing as compared with transverse dimers, the latter actually consistently lead to output with higher coherence. Intriguingly, and somewhat counterintuitively, we find that transverse dimers only reach peak output at an intermediate dimer separation at which field confinement is not the strongest. We show that this is due to low radiative decay rates of transverse dimers with significant dimer gaps. We also find that transverse dimers outperform longitudinal dimers in terms of output intensity in a weakly pumped sparse gain medium made of dimers with relatively large separations. Moreover, in all the configurations considered, we find that the second-order coherence of the spasing output shows a peaked behavior just before the threshold, suggesting that the coherence is a useful indicator of spasing. Even though the scheme we describe is focused on dimers, owing to the generic form of the analysis presented, it can be easily extended to investigate spasing in the bright modes of multiple coupled plasmon sources.

Original languageEnglish
Article number085439
Number of pages13
JournalPhysical Review B
Volume100
Issue number8
DOIs
Publication statusPublished - 29 Aug 2019

Cite this

Warnakula, Tharindu ; Gunapala, Sarath D. ; Stockman, Mark I. ; Premaratne, Malin. / Cavity quantum electrodynamic analysis of spasing in nanospherical dimers. In: Physical Review B. 2019 ; Vol. 100, No. 8.
@article{b303697ae3f740ea8fe95625f3bc13c4,
title = "Cavity quantum electrodynamic analysis of spasing in nanospherical dimers",
abstract = "We present a detailed cavity quantum electrodynamic model of a nanospherical dimer and use it to analyze bright hybrid spasing modes there. Using an approximate numerical scheme, we model the complete spasing system as an open quantum system under the Lindblad dissipator formalism. We show that while in general the longitudinal dimer setups display higher intensity spasing as compared with transverse dimers, the latter actually consistently lead to output with higher coherence. Intriguingly, and somewhat counterintuitively, we find that transverse dimers only reach peak output at an intermediate dimer separation at which field confinement is not the strongest. We show that this is due to low radiative decay rates of transverse dimers with significant dimer gaps. We also find that transverse dimers outperform longitudinal dimers in terms of output intensity in a weakly pumped sparse gain medium made of dimers with relatively large separations. Moreover, in all the configurations considered, we find that the second-order coherence of the spasing output shows a peaked behavior just before the threshold, suggesting that the coherence is a useful indicator of spasing. Even though the scheme we describe is focused on dimers, owing to the generic form of the analysis presented, it can be easily extended to investigate spasing in the bright modes of multiple coupled plasmon sources.",
author = "Tharindu Warnakula and Gunapala, {Sarath D.} and Stockman, {Mark I.} and Malin Premaratne",
year = "2019",
month = "8",
day = "29",
doi = "10.1103/PhysRevB.100.085439",
language = "English",
volume = "100",
journal = "Physical Review B",
issn = "2469-9950",
publisher = "American Physical Society",
number = "8",

}

Cavity quantum electrodynamic analysis of spasing in nanospherical dimers. / Warnakula, Tharindu; Gunapala, Sarath D.; Stockman, Mark I.; Premaratne, Malin.

In: Physical Review B, Vol. 100, No. 8, 085439, 29.08.2019.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Cavity quantum electrodynamic analysis of spasing in nanospherical dimers

AU - Warnakula, Tharindu

AU - Gunapala, Sarath D.

AU - Stockman, Mark I.

AU - Premaratne, Malin

PY - 2019/8/29

Y1 - 2019/8/29

N2 - We present a detailed cavity quantum electrodynamic model of a nanospherical dimer and use it to analyze bright hybrid spasing modes there. Using an approximate numerical scheme, we model the complete spasing system as an open quantum system under the Lindblad dissipator formalism. We show that while in general the longitudinal dimer setups display higher intensity spasing as compared with transverse dimers, the latter actually consistently lead to output with higher coherence. Intriguingly, and somewhat counterintuitively, we find that transverse dimers only reach peak output at an intermediate dimer separation at which field confinement is not the strongest. We show that this is due to low radiative decay rates of transverse dimers with significant dimer gaps. We also find that transverse dimers outperform longitudinal dimers in terms of output intensity in a weakly pumped sparse gain medium made of dimers with relatively large separations. Moreover, in all the configurations considered, we find that the second-order coherence of the spasing output shows a peaked behavior just before the threshold, suggesting that the coherence is a useful indicator of spasing. Even though the scheme we describe is focused on dimers, owing to the generic form of the analysis presented, it can be easily extended to investigate spasing in the bright modes of multiple coupled plasmon sources.

AB - We present a detailed cavity quantum electrodynamic model of a nanospherical dimer and use it to analyze bright hybrid spasing modes there. Using an approximate numerical scheme, we model the complete spasing system as an open quantum system under the Lindblad dissipator formalism. We show that while in general the longitudinal dimer setups display higher intensity spasing as compared with transverse dimers, the latter actually consistently lead to output with higher coherence. Intriguingly, and somewhat counterintuitively, we find that transverse dimers only reach peak output at an intermediate dimer separation at which field confinement is not the strongest. We show that this is due to low radiative decay rates of transverse dimers with significant dimer gaps. We also find that transverse dimers outperform longitudinal dimers in terms of output intensity in a weakly pumped sparse gain medium made of dimers with relatively large separations. Moreover, in all the configurations considered, we find that the second-order coherence of the spasing output shows a peaked behavior just before the threshold, suggesting that the coherence is a useful indicator of spasing. Even though the scheme we describe is focused on dimers, owing to the generic form of the analysis presented, it can be easily extended to investigate spasing in the bright modes of multiple coupled plasmon sources.

UR - http://www.scopus.com/inward/record.url?scp=85072528600&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.100.085439

DO - 10.1103/PhysRevB.100.085439

M3 - Article

VL - 100

JO - Physical Review B

JF - Physical Review B

SN - 2469-9950

IS - 8

M1 - 085439

ER -