Refractive index changes and absorption coefficients in a spherical quantum dot with parabolic potential

Çakır, Bekir; Yakar, Yusuf; Özmen, Ayhan

doi:10.1016/j.jlumin.2012.03.065

Cited by 92 publications

(11 citation statements)

References 44 publications

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“…As seen, the matrix elements oscillate as decreasing‐increasing‐decreasing for the change from 40 to 80 to 130 to 160 meV in the confinement energy. When considering that there is no such oscillation for the quantum dot without VDP, [ 35 ] we found that VDP has remarkable potential on the dynamics of the electron encompassed in a quantum dot. In Figure 1B, when ℏ ω 0 = 120 meV, the effect of the harmonic form factor (namely, VDP effect as

{γρ}_{0} = 3, 6, 12, 24 a_{B}^{- 2}

) on TRICs is demonstrated as a function of the incident photon energy.…”

Section: Resultsmentioning

confidence: 99%

Optical analysis of quantum dot with velocity‐dependent potential

Bahar

Ungan

Kaya

et al. 2020

Int J of Quantum Chemistry

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In this study, for the first time, the velocity‐dependent potential (VDP) effects on the total refractive index changes (TRICs) and the total absorption coefficients (TACs) of the parabolic quantum dot with spherical confinement, generated by GaAs/GaAlAs heterostructure, are comprehensively investigated. In order to obtain the subband energy spectra and the electronic wave function of the quantum dot system, the wave equation is numerically solved due to the VDP's complexity by using Runge‐Kutta‐Fehlberg method within the effective mass approximation. The nonlinear optical specifications of the quantum dot with velocity‐dependent potential (QDVDP) are analyzed using the compact density matrix formalism within the framework of the iterative method. To investigate the optical specifications of QDVDP, the isotropic form factor of VDP is taken into consideration as the harmonic oscillator type, F(r) = γρ0r2 (being γ and ρ0 are constants). Optical analysis is also executed for parabolic encompassing under the influence of VDP, as well as VDP, analyzing for TRICs and TACs of QDVDP, for which the result is quite a change compared to cases without VDP due to the symmetry‐breaking repercussion on system confinement of VDP. The main motivation of the present study is to clearly distinguish VDP effects on optical properties of the quantum dot, carrying out an analysis on optimal range and alternative parameter for optical properties.

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{γρ}_{0} = 3, 6, 12, 24 a_{B}^{- 2}

) on TRICs is demonstrated as a function of the incident photon energy.…”

Section: Resultsmentioning

confidence: 99%

Optical analysis of quantum dot with velocity‐dependent potential

Bahar

Ungan

Kaya

et al. 2020

Int J of Quantum Chemistry

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“…Another active medium that can be considered for modulo 2π beam steering is quantum dots. 24,25 Quantum dots have the advantage that both polarizations can be changed based on applying voltage rather than just one polarization, and they can react fast, similar to EO materials, and much faster than LCs. To date, not much has, however, been published using quantum dots for index change, but recently Portland, Oregon based Inv3ctus, Inc. has been granted a patent on a nonmechanical beam scanning technology employing a quantum dot phased array (QDPA).…”

Section: Quantum Dot Modulo 2π Opasmentioning

confidence: 99%

Progress and opportunities in the development of nonmechanical beam steering for electro-optical systems

McManamon¹,

Ataei²

2019

Opt. Eng.

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We discuss over three decades of progress in nonmechanical beam steering, provide a comparison of approaches being developed, and comment on promising approaches not yet fully developed. Most of the work in nonmechanical beam steering has been for narrowband optical systems, but a brief discussion is provided of broadband. The majority of the nonmechanical approaches to beam steering create a tilted optical path delay (OPD) to change the wavefront, but some directly create a phase delay. OPD-based approaches may be true time delay, with no resets or modulo 2πn optical phased arrays that have resets. Most of the nonmechanical optical beam steering approaches tilt an existing wavefront and are called space fed approaches, because the beam is already formed when the wavefront is tilted. For the majority of radar nonmechanical beam steering, the tilted wavefront is formed by individual transmit/receive modules. Periodic structures (gratings) spread different wavelengths of light in angle, thus steering light, and are also used for nonmechanical steering. Our paper is derived from a conference paper presented at Photonics West in February 2019.

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“…Low-dimensional electronic devices such as photo detectors, electro-optical modulators, and far-infrared laser amplifiers are pioneering products of advanced semiconductor technologies. Studies on the electronic and optical properties of these quantum structures have consequently become an essential branch of the concerning research as a lot of work have been devoted to the determination of the transition energies, the absorption coefficients, and the refraction index changes [1][2][3][4][5][6][7][8][9][10]. It has been shown that the potential profile of structure strongly affects the linear and nonlinear optical absorption coefficients [1][2][3].…”

Section: Introductionmentioning

confidence: 99%

“…The photon energies of the total absorption coefficients exhibit the red shift as the hydrostatic pressure is increased while the blue shift is observed if the temperature is increased [5,6]. The radius of the dot, the incident optical intensity, the stoichiometric * corresponding author; e-mail: bahadirbekar@trakya.edu.tr ratio of the constituent elements, and whether the dot is doped with the impurity or not have been proved to be characterizing parameters on the linear and the nonlinear 1s-1p, 1p-1d, and 1d-1f transitions in a spherical quantum dot [8,9]. The photon energies of the optical absorption coefficients showed blue shift with the increasing diameters of the gold nano particle for the hybrid structure in which the metallic nano-particle was coupled with a multilayered quantum dot [10].…”

Section: Introductionmentioning

confidence: 99%

The Effect on the Optical Absorption Coefficients due to the Positions in the Plane of Square GaAs / Al(GaAs) Quantum Well Wire under the Laser Field

et al. 2019

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The laser field effects on the electronic and optical properties depending on two different positions in the plane of GaAs/Al (GaAs) quantum wire with square cross sections have been investigated. The electron energy levels and the electronic wave functions of the wires are calculated using the finite differences method within the effective mass approximation. The differences of the total absorption coefficients and the reflection index changes sourced from the cross-sectional shape were determined and explained with and without laser field. From the results the blue shift and red shift effects on the total absorption coefficients and the reflection index changes were identified depending on the laser field strength and the positions of square GaAs/Al(GaAs) quantum well wire in the plane.

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Refractive index changes and absorption coefficients in a spherical quantum dot with parabolic potential

Cited by 92 publications

References 44 publications

Optical analysis of quantum dot with velocity‐dependent potential

Optical analysis of quantum dot with velocity‐dependent potential

Progress and opportunities in the development of nonmechanical beam steering for electro-optical systems

The Effect on the Optical Absorption Coefficients due to the Positions in the Plane of Square GaAs / Al(GaAs) Quantum Well Wire under the Laser Field

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