OPTIMAL DESIGN OF SINGLE-PHOTON SOURCE EMISSION FROM A QUANTUM-DOT IN MICRO-PILLAR MICROCAVITY

We have modelled wavelength scale micro-pillar microcavities of group III-V semiconductor materials using the 3-D finite difference time domain (FDTD) method. A broad band dipole source within the microcavity probes the microcavity mode structure and spectrum. We then investigated the modifications to spontaneous emission of photons form narrowband emitters (e.g. quantum dots) at the centre of the resonance. We find strongly enhanced emission due to small modal volumes and high quality factor (Q-factor). A large fraction of the quantum-dot spontaneous emission is coupled into the fundamental cavity mode. Increasing the number of mirror pairs in the bottom distributed Bragg reflector (DBR) obviously reduces the bottom light leakage, leading to light collection efficiency up to 90%. Moreover, we are now looking at more sophisticated structures with both lateral and perpendicular confinements based on annular and photonic crystal defect cavities in order to suppress the remaining sidewall scattering.

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Au Microdisk-Size Dependence of Quantum Dot Emission from the Hybrid Metal-Distributed Bragg Reflector Structures Employed for Single Photon Sources

Chinese Physics Letters ◽

10.1088/0256-307x/32/10/107804 ◽

2015 ◽

Vol 32 (10) ◽

pp. 107804 ◽

Cited By ~ 2

Author(s):

Hai-Yan Wang ◽

Dan Su ◽

Shuang Yang ◽

Xiu-Ming Dou ◽

Hai-Jun Zhu ◽

...

Keyword(s):

Quantum Dot ◽

Size Dependence ◽

Single Photon ◽

Bragg Reflector ◽

Distributed Bragg Reflector ◽

Photon Sources

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A new III-V Nanowire-Quantum Dot Single Photon Source with Improved Purcell Factor for Quantum Communication

10.21203/rs.3.rs-530578/v1 ◽

2021 ◽

Author(s):

shahramm mohammad nejad ◽

Amine Mahmoudi ◽

Hossein Arab

Keyword(s):

Quantum Dot ◽

Quantum Communication ◽

Single Photon ◽

Fdtd Method ◽

Dipole Source ◽

Single Photon Source ◽

Purcell Factor ◽

Pbs Quantum Dots ◽

Difference Time ◽

Photon Source

Abstract In this work, the finite difference time domain (FDTD) method has been utilized to simulate the propagation emission from PbS quantum dots in a hexagonal InP nanowire as a single photon source. The effect of height and radius of the nanowire as well as the location and orientation of the dipole source in the Purcell factor and Quality factor of the nanowire have been investigated. A broadband electric dipole source has been used to model the quantum dot and the effect of shape and radius of PbS quantum dot have been investigated in the final results. The conclusive structure has been optimized to a nanowire with hexagonal cross section with radius of 220nm and height of 10um. The emission peak obtained above 1um with Purcell factor of 4.72 which is in good agreement with cases have been used as single photon source in quantum communication.

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Неклассические источники света на основе селективно позиционированных микролинзовых структур и (111) In(Ga)As квантовых точек

Физика и техника полупроводников ◽

10.21883/ftp.2019.10.48286.32 ◽

2019 ◽

Vol 53 (10) ◽

pp. 1338

Author(s):

И.А. Деребезов ◽

В.А. Гайслер ◽

А.В. Гайслер ◽

Д.В. Дмитриев ◽

А.И. Торопов ◽

...

Keyword(s):

Quantum Dots ◽

Quantum Dot ◽

Single Photon ◽

Photon Emission ◽

Bragg Reflector ◽

Entangled Photons ◽

Single Photon Emission ◽

Distributed Bragg Reflector ◽

Natural Width ◽

Single Quantum Dot

Hybrid microcavity for single quantum dot based emitters has been developed and realized. The microcavity consists of semiconductor distributed Bragg reflector and microlens, which is selectively positioned over a single (111) In(Ga)As quantum dot. We have demonstrated pure single photon emission with g(2)(0) = 0.07. The fine structure of exciton states of (111) In(Ga)As quantum dots is studied. It is shown that the splitting of exciton states is comparable with the natural width of exciton lines, which is of great interest for the design of emitters of pairs of entangled photons on the basis of these quantum dots.

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Tailoring the Geometry of Bottom-Up Nanowires: Application to High Efficiency Single Photon Sources

Nanomaterials ◽

10.3390/nano11051201 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1201

Author(s):

Dan Dalacu ◽

Philip J. Poole ◽

Robin L. Williams

Keyword(s):

Quantum Dot ◽

High Efficiency ◽

Emission Rate ◽

Single Photon ◽

Collection Efficiency ◽

Photon Emission ◽

Device Performance ◽

Bottom Up ◽

Selective Area ◽

Photon Generation

For nanowire-based sources of non-classical light, the rate at which photons are generated and the ability to efficiently collect them are determined by the nanowire geometry. Using selective-area vapour-liquid-solid epitaxy, we show how it is possible to control the nanowire geometry and tailor it to optimise device performance. High efficiency single photon generation with negligible multi-photon emission is demonstrated using a quantum dot embedded in a nanowire having a geometry tailored to optimise both collection efficiency and emission rate.

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Narrow Linewidth Distributed Bragg Reflectors Based on InGaN/GaN Laser

Micromachines ◽

10.3390/mi10080529 ◽

2019 ◽

Vol 10 (8) ◽

pp. 529 ◽

Cited By ~ 2

Author(s):

Xie ◽

Li ◽

Liao ◽

Deng ◽

Wang ◽

...

Keyword(s):

Gallium Nitride ◽

Visible Light ◽

Communication Systems ◽

Fdtd Method ◽

Visible Light Communication ◽

Bragg Reflector ◽

Duty Ratio ◽

Light Sources ◽

Distributed Bragg Reflector ◽

Dbr Lasers

A variety of emerging technologies, such as visible light communication systems, require narrow linewidths and easy-to-integrate light sources. Such a requirement could be potentially fulfilled with the distributed Bragg reflector (DBR) lasers, which are also promising for the monolithical integration with other optical components. The InGaN/GaN-based surface etched DBR is designed and optimized using the finite-difference-time-domain (FDTD) method to obtain very narrow-band reflectors that can serve as a wavelength filter. The results reveal that the ultimate reflectivity depends on the grating period and duty ratio of the DBR. Based on the design, the DBR lasers with various duty ratios are fabricated, specifically, the 19th, 13th and 3rd order DBR grating with duty ratio set as 50%/75%/95%. The minimum linewidth could be achieved at 0.45 nm from the 19th order grating with a 75% duty ratio. For comparison, the Fabry–Pérot (F–P) based on the same indium gallium nitride/gallium nitride (InGaN/GaN) epitaxial wafer are fabricated. The full width at half maximum (FWHM) of the DBR laser shrank by 65% compared to that of the conventional F–P laser, which might be helpful in the application of the visible light communication system.

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Light efficiency enhanced quantum dot color conversion layer based on a distributed Bragg reflector

10.1117/12.2606534 ◽

2021 ◽

Author(s):

Yuanyuan Ye ◽

Sheng Xu ◽

Enguo Chen ◽

Yun Ye ◽

Xinpei Hu ◽

...

Keyword(s):

Quantum Dot ◽

Bragg Reflector ◽

Distributed Bragg Reflector ◽

Color Conversion ◽

Light Efficiency

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Quantum-Dot-Based Photon Emission and Media Conversion for Quantum Information Applications

Advances in Mathematical Physics ◽

10.1155/2010/391607 ◽

2010 ◽

Vol 2010 ◽

pp. 1-13 ◽

Cited By ~ 7

Author(s):

H. Kumano ◽

H. Nakajima ◽

S. Ekuni ◽

Y. Idutsu ◽

H. Sasakura ◽

...

Keyword(s):

Quantum Information ◽

Quantum Dot ◽

Electron Spin ◽

Single Photon ◽

Collection Efficiency ◽

Photon Emission ◽

Exciton State ◽

Photon Pair ◽

Photon Polarization ◽

Pair Generation

Single-photon as well as polarization-correlated photon pair emission from a single semiconductor quantum dots is demonstrated. Single photon generation and single photon-pair generation with little uncorrelated multiphoton emission and the feasibility of media conversion of the quantum states between photon polarization and electron spin are fundamental functions for quantum information applications. Mutual media conversion for the angular momentum between photon polarization and electron spin is also achieved with high fidelity via positively charged exciton state without external magnetic field. This is a clear indication that the coupling of photon polarizations and electron spins keeps secured during whole processes before photon emission. Possibility of a metal-embedded structure is demonstrated with the observation of drastic enhancement of excitation and/or collection efficiency of luminescence as well as clear antibunching of photons generated from a quantum dot.

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Semiconductor Laser Linewidth Theory Revisited

Applied Sciences ◽

10.3390/app11136004 ◽

2021 ◽

Vol 11 (13) ◽

pp. 6004

Author(s):

Hans Wenzel ◽

Markus Kantner ◽

Mindaugas Radziunas ◽

Uwe Bandelow

Keyword(s):

Spontaneous Emission ◽

Numerical Study ◽

Analytical Formula ◽

Reduction Factor ◽

Bragg Reflector ◽

Hole Burning ◽

Distributed Bragg Reflector ◽

Theoretical Understanding ◽

Longitudinal Modes ◽

Coupled Wave Equations

More and more applications require semiconductor lasers distinguished not only by large modulation bandwidths or high output powers, but also by small spectral linewidths. The theoretical understanding of the root causes limiting the linewidth is therefore of great practical relevance. In this paper, we derive a general expression for the calculation of the spectral linewidth step by step in a self-contained manner. We build on the linewidth theory developed in the 1980s and 1990s but look from a modern perspective, in the sense that we choose as our starting points the time-dependent coupled-wave equations for the forward and backward propagating fields and an expansion of the fields in terms of the stationary longitudinal modes of the open cavity. As a result, we obtain rather general expressions for the longitudinal excess factor of spontaneous emission (K-factor) and the effective α-factor including the effects of nonlinear gain (gain compression) and refractive index (Kerr effect), gain dispersion, and longitudinal spatial hole burning in multi-section cavity structures. The effect of linewidth narrowing due to feedback from an external cavity often described by the so-called chirp reduction factor is also automatically included. We propose a new analytical formula for the dependence of the spontaneous emission on the carrier density avoiding the use of the population inversion factor. The presented theoretical framework is applied to a numerical study of a two-section distributed Bragg reflector laser.

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