Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Journal of the Optical Society of America B

Photon absorption in interacting quantum dots doped in nanofibers

Mahi R. Singh, Daniel G. Schindel

Published Nov 23, 2010• 5 citations
Publisher

Abstract

We study the coupling between quantum dots through the dipole–dipole interaction in photonic nanofibers manufactured by embedding a dielectric material into a photonic crystal. The embedded dielectric material is doped with an ensemble of three-level quantum dots. A probe field is applied to monitor the absorption, and a control field is applied to induce dipole moments in quantum dots. Dipoles are induced in quantum dots due to the external fields, and they interact with each other via the dipole–dipole interaction. Quantum dots also interact with the nanofiber through the electron–bound photon interaction. The absorption coefficient has been calculated using the density matrix method, and the dipole–dipole interaction has been evaluated in the mean field approximation. It is found that the absorption spectrum splits from one peak to two peaks by the dipole–dipole interaction. The splitting of peaks can be controlled by either the resonance energy of quantum dots or bound photon states of the nanofiber.

DOI
10.1364/josab.27.002759

Related papers

Controlling photon absorption in photonic nanowires via dipole–dipole interaction

Mahi R. Singh

The effect of the dipole-dipole interaction (DDI) on absorption processes has been investigated in photonic nanowires. They are manufactured by embedding a photonic crystal into another crystal. The embedded crystal is doped with an ensemble of three-level quantum dots. A probe field is applied to monitor the absorption coefficient. A control field is applied to induce dipole moments in quantum dots. Owing to these fields dipoles are induced in quantum dots, and they interact with each other via the DDI. Quantum dots also interact with bound photon states of the nanowire via the electron-bound photon interaction. It is found that the system can be switched from a transparent state to an absorbing state through the DDI. The switching mechanism can be controlled by changing the location of a resonant energy in the quantum dots.

Optics Letters•Sep 16, 2009•12 citations

Effect of dipole–dipole interactions on the one-photon and two-photon photoluminescence in an ensemble of quantum dots doped in a polymer matrix

Patrick D. Persaud, Mahi R. Singh

We have developed a theory for the one-photon and two-photon fluorescence of a nanohybrid composite comprised of an ensemble of quantum dots encased in a matrix of polymer. The quantum dots are comprised of four-level quantum emitters encased within a coating of dielectric material. The fluorescence of the quantum dot system is calculated using the master equation method where dipole–dipole interaction (DDI) coupling is present. The application of a probe field to the nanohybrid composite material in conjunction with the DDI between the quantum dots generates an enhancement of both the single-photon and double-photon fluorescence, and in certain conditions causes spectrum splitting. With a strong DDI field, the two-photon emission spectrum experiences slight quenching and shifts from one peak to two peaks. The dressed states are a result of strong coupling effects between the DDI field and the quantum dots. We generated an analytical expression for the fluorescence spectrum and intensity, and quantitatively compared it to experimental data in which ZnSe quantum dots were embedded within a P3HT polymer film, with our theory strongly correlating with the experiment. We also quantitatively compared our theory with experimental data that demonstrated the single-photon emission spectrum of colloidal quantum dots comprised of a CdZnS/ZnS gradient structure in varying probe field strengths. We found that our theory predicted the spectrum peak splitting that the experiment produced.

Journal of the Optical Society of America B•Oct 8, 2020•15 citations

Plasmonic effect on quantum coherence and interference in metallic photonic crystals doped with quantum dots

Ali Hatef, Mahi R. Singh

We have studied the effect of plasma energy on the absorption coefficient of metallic photonic crystals doped with an ensemble of three-level quantum dots, which are interacting with each other via dipole-dipole interaction. The quantum dots are also interacting with coupled plasma-photon modes present in the system. A probe laser field is applied in order to study the absorption coefficient. We also consider the effect of quantum interference in our simulations, whereby two absorbed photons interfere with one another. Here the density matrix method has been used to calculate the steady-state and transient behavior of the absorption coefficient for the system. Two different field configurations are considered in our numerical simulations. In the first configuration, a probe field couples the ground state and two closely excited states. Absorption occurs due to transitions from the ground state to the two excited states. It is found that the position of the transparent peak moves when the plasma energy is changed. In other words, changing the plasma energy causes the system to switch between a transparent and an absorbing state. The strong coupling between plasmons and the quantum dots is responsible for this phenomenon. In the second configuration, the probe field couples with only one excited state, while a pump field couples to the other excited state. The transition between excited states is dipole forbidden. We observed that the peak in the absorption profile splits into two and also that the system exhibits gain with inversion due to the change in the plasma frequency, which is caused by quantum interference and coherence. These are interesting results and can be used make nanoscale plasma devices.

Physical Review A•Jun 21, 2010•52 citations

Dipole–dipole interaction in nanoscale photonic quantum wells

Mahi R. Singh

Abstract The dipole–dipole interaction (DDI) has been studied in photonic quantum wells are simulated from two photonic crystals say A and B. An ensemble of nanoparticles is doped within the quantum well layer. Nanoparticles are interacting with each other via DDI. The absorption spectrum has been calculated by using the time dependent Schrodinger equation method. A probe field is applied to measure the absorption spectrum. Numerical simulations for the absorption coefficient have been performed. It has been found that in the absence of DDI the spectrum has two peaks and a minimum at zero detuning. However, in the presence of the large DDI coupling both peaks disappear and a large minimum appears. This means that the positions and heights of peaks can be changed due to DDI interaction. This study can be used to make new types of optical devices. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

physica status solidi (a)•Apr 21, 2009•3 citations

Dipole–Dipole Interaction in Two-Photon Spectroscopy of Metallic Nanohybrids

Mahi R. Singh, Patrick D. Persaud

We have developed a theory for the two-photon fluorescence in nanohybrids made of an ensemble of metallic nanorod shells and an ensemble of quantum emitters. A metallic nanorod shell is made of a metallic rod and dielectric shell. We consider that the quantum emitters are four-level quantum systems. When a probe laser light falls on the metallic nanorod shells, the surface plasmon polariton electric field is produced at the interface between the metallic nanorod and dielectric shell. This electric field, along with the probe field, induces dipoles in the quantum emitters and nanorod shells. These dipoles interact with each other via the dipole–dipole interaction. The two-photon fluorescence has been calculated by using the quantum density matrix method in the presence of the dipole–dipole interaction (coupling). Analytical expressions of the two-photon fluorescence have been derived in the presence of the dipole–dipole interaction. We showed that that the two-photon process is made of two terms. The first term is the two-photon process due to the two probe field photons. On other the hand, the second term is made of one DDI field photon and one probe field photon. It is found that the surface plasmon polariton resonance energy is not resonant with the exciton energy, the two-photon fluorescence spectrum splits from one peak to three peaks. The splitting in the spectrum is due to the presence of the dressed states created in the system due to the strong dipole–dipole interaction. We also compared our theory with the experimental data of the metallic nanohybrid system made of metallic nanorod shells and quantum emitters (T790 molecules) and found a good agreement between the theory and the experiments.

The Journal of Physical Chemistry C•Feb 23, 2020•50 citations

Fluorescence from a quantum dot and metallic nanosphere hybrid system

Daniel G. Schindel, Mahi R. Singh

We present energy absorption and interference in a quantum dot-metallic nanosphere system embedded on a dielectric substrate. A control field is applied to induce dipole moments in the nanosphere and the quantum dot, and a probe field is applied to monitor absorption. Dipole moments in the quantum dot or the metal nanosphere are induced, both by the external fields and by each other's dipole fields. Thus, in addition to direct polarization, the metal nanosphere and the quantum dot will sense one another via the dipole-dipole interaction. The density matrix method was used to show that the absorption spectrum can be split from one peak to two peaks by the control field, and this can also be done by placing the metal sphere close to the quantum dot. When the two are extremely close together, a self-interaction in the quantum dot produces an asymmetry in the absorption peaks. In addition, the fluorescence efficiency can be quenched by the addition of a metal nanosphere. This hybrid system could be used to create ultra-fast switching and sensing nanodevices.

AIP conference proceedings•Jan 1, 2014•0 citations
We study the coupling between quantum dots through the dipole–dipole interaction in photonic nanofibers manufactured by embedding a dielectric material into a photonic crystal. The embedded dielectric material is doped with an ensemble of three-level quantum dots. A probe field is applied to monitor the absorption, and a control field is applied to induce dipole moments in quantum dots. Dipoles are induced in quantum dots due to the external fields, and they interact with each other via the dipole–dipole interaction. Quantum dots also interact with the nanofiber through the electron–bound photon interaction. The absorption coefficient has been calculated using the density matrix method, and the dipole–dipole interaction has been evaluated in the mean field approximation. It is found that the absorption spectrum splits from one peak to two peaks by the dipole–dipole interaction. The splitting of peaks can be controlled by either the resonance energy of quantum dots or bound photon states of the nanofiber.
The effect of the dipole-dipole interaction (DDI) on absorption processes has been investigated in photonic nanowires. They are manufactured by embedding a photonic crystal into another crystal. The embedded crystal is doped with an ensemble of three-level quantum dots. A probe field is applied to monitor the absorption coefficient. A control field is applied to induce dipole moments in quantum dots. Owing to these fields dipoles are induced in quantum dots, and they interact with each other via the DDI. Quantum dots also interact with bound photon states of the nanowire via the electron-bound photon interaction. It is found that the system can be switched from a transparent state to an absorbing state through the DDI. The switching mechanism can be controlled by changing the location of a resonant energy in the quantum dots.
We have developed a theory for the one-photon and two-photon fluorescence of a nanohybrid composite comprised of an ensemble of quantum dots encased in a matrix of polymer. The quantum dots are comprised of four-level quantum emitters encased within a coating of dielectric material. The fluorescence of the quantum dot system is calculated using the master equation method where dipole–dipole interaction (DDI) coupling is present. The application of a probe field to the nanohybrid composite material in conjunction with the DDI between the quantum dots generates an enhancement of both the single-photon and double-photon fluorescence, and in certain conditions causes spectrum splitting. With a strong DDI field, the two-photon emission spectrum experiences slight quenching and shifts from one peak to two peaks. The dressed states are a result of strong coupling effects between the DDI field and the quantum dots. We generated an analytical expression for the fluorescence spectrum and intensity, and quantitatively compared it to experimental data in which ZnSe quantum dots were embedded within a P3HT polymer film, with our theory strongly correlating with the experiment. We also quantitatively compared our theory with experimental data that demonstrated the single-photon emission spectrum of colloidal quantum dots comprised of a CdZnS/ZnS gradient structure in varying probe field strengths. We found that our theory predicted the spectrum peak splitting that the experiment produced.
We have studied the effect of plasma energy on the absorption coefficient of metallic photonic crystals doped with an ensemble of three-level quantum dots, which are interacting with each other via dipole-dipole interaction. The quantum dots are also interacting with coupled plasma-photon modes present in the system. A probe laser field is applied in order to study the absorption coefficient. We also consider the effect of quantum interference in our simulations, whereby two absorbed photons interfere with one another. Here the density matrix method has been used to calculate the steady-state and transient behavior of the absorption coefficient for the system. Two different field configurations are considered in our numerical simulations. In the first configuration, a probe field couples the ground state and two closely excited states. Absorption occurs due to transitions from the ground state to the two excited states. It is found that the position of the transparent peak moves when the plasma energy is changed. In other words, changing the plasma energy causes the system to switch between a transparent and an absorbing state. The strong coupling between plasmons and the quantum dots is responsible for this phenomenon. In the second configuration, the probe field couples with only one excited state, while a pump field couples to the other excited state. The transition between excited states is dipole forbidden. We observed that the peak in the absorption profile splits into two and also that the system exhibits gain with inversion due to the change in the plasma frequency, which is caused by quantum interference and coherence. These are interesting results and can be used make nanoscale plasma devices.
Abstract The dipole–dipole interaction (DDI) has been studied in photonic quantum wells are simulated from two photonic crystals say A and B. An ensemble of nanoparticles is doped within the quantum well layer. Nanoparticles are interacting with each other via DDI. The absorption spectrum has been calculated by using the time dependent Schrodinger equation method. A probe field is applied to measure the absorption spectrum. Numerical simulations for the absorption coefficient have been performed. It has been found that in the absence of DDI the spectrum has two peaks and a minimum at zero detuning. However, in the presence of the large DDI coupling both peaks disappear and a large minimum appears. This means that the positions and heights of peaks can be changed due to DDI interaction. This study can be used to make new types of optical devices. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
We have developed a theory for the two-photon fluorescence in nanohybrids made of an ensemble of metallic nanorod shells and an ensemble of quantum emitters. A metallic nanorod shell is made of a metallic rod and dielectric shell. We consider that the quantum emitters are four-level quantum systems. When a probe laser light falls on the metallic nanorod shells, the surface plasmon polariton electric field is produced at the interface between the metallic nanorod and dielectric shell. This electric field, along with the probe field, induces dipoles in the quantum emitters and nanorod shells. These dipoles interact with each other via the dipole–dipole interaction. The two-photon fluorescence has been calculated by using the quantum density matrix method in the presence of the dipole–dipole interaction (coupling). Analytical expressions of the two-photon fluorescence have been derived in the presence of the dipole–dipole interaction. We showed that that the two-photon process is made of two terms. The first term is the two-photon process due to the two probe field photons. On other the hand, the second term is made of one DDI field photon and one probe field photon. It is found that the surface plasmon polariton resonance energy is not resonant with the exciton energy, the two-photon fluorescence spectrum splits from one peak to three peaks. The splitting in the spectrum is due to the presence of the dressed states created in the system due to the strong dipole–dipole interaction. We also compared our theory with the experimental data of the metallic nanohybrid system made of metallic nanorod shells and quantum emitters (T790 molecules) and found a good agreement between the theory and the experiments.
We present energy absorption and interference in a quantum dot-metallic nanosphere system embedded on a dielectric substrate. A control field is applied to induce dipole moments in the nanosphere and the quantum dot, and a probe field is applied to monitor absorption. Dipole moments in the quantum dot or the metal nanosphere are induced, both by the external fields and by each other's dipole fields. Thus, in addition to direct polarization, the metal nanosphere and the quantum dot will sense one another via the dipole-dipole interaction. The density matrix method was used to show that the absorption spectrum can be split from one peak to two peaks by the control field, and this can also be done by placing the metal sphere close to the quantum dot. When the two are extremely close together, a self-interaction in the quantum dot produces an asymmetry in the absorption peaks. In addition, the fluorescence efficiency can be quenched by the addition of a metal nanosphere. This hybrid system could be used to create ultra-fast switching and sensing nanodevices.