M. Hopkinson
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View article: Photonic crystal enhanced light emitting diodes fabricated by single pulse laser interference lithography
Photonic crystal enhanced light emitting diodes fabricated by single pulse laser interference lithography Open
Integration of photonic crystal (PhC) configurations onto the surfaces of light-emitting diodes (LEDs) can play an important role in enhancing light extraction efficiency. While the literature is rich with various PhC fabrication approache…
View article: Fabrication of quantum dot and ring arrays by direct laser interference patterning for nanophotonics
Fabrication of quantum dot and ring arrays by direct laser interference patterning for nanophotonics Open
Epitaxially grown semiconductor quantum dots (QDs) and quantum rings (QRs) have been demonstrated to be excellent sources of single photons and entangled photon pairs enabling applications within quantum photonics. The emerging field of QD…
View article: Characterisation, modelling and design of cut-off wavelength of InGaAs/GaAsSb type-II superlattice photodiodes
Characterisation, modelling and design of cut-off wavelength of InGaAs/GaAsSb type-II superlattice photodiodes Open
InGaAs/GaAsSb type-II superlattice (T2SL) photodiodes grown on InP substrates are an alternative detector technology for applications operating in the short wavelength infrared band. Their cut-off wavelengths are heavily influenced by the …
View article: Ordered GaAs quantum dots by droplet epitaxy using <i>in situ</i> direct laser interference patterning
Ordered GaAs quantum dots by droplet epitaxy using <i>in situ</i> direct laser interference patterning Open
We report the fabrication of highly ordered arrays of GaAs/AlGaAs quantum dots (QDs) by droplet epitaxy using in situ direct laser interference patterning. Two-dimensional arrays of Ga droplets with a periodicity of ∼300 nm are initially f…
View article: Optical Frequency Comb Generation via Cascaded Intensity and Phase Photonic Crystal Modulators
Optical Frequency Comb Generation via Cascaded Intensity and Phase Photonic Crystal Modulators Open
Nanophotonics, driven by low processing power and high density integration, is appearing as the next logical step for microwave photonics. Optical frequency combs (OFCs), which play a vital role in integrated microwave photonics, have not …
View article: Ordered GaAs quantum dots by droplet epitaxy
Ordered GaAs quantum dots by droplet epitaxy Open
We report the fabrication of highly ordered arrays of GaAs/AlGaAs quantum dots (QDs) by droplet epitaxy using in-situ direct laser interference patterning (DLIP). Two-dimensional arrays of Ga droplets with a periodicity of ~ 300 nm are ini…
View article: Direct patterning of periodic semiconductor nanostructures using single-pulse nanosecond laser interference
Direct patterning of periodic semiconductor nanostructures using single-pulse nanosecond laser interference Open
We demonstrate an effective method for fabricating large area periodic two-dimensional semiconductor nanostructures by means of single-pulse laser interference. Utilizing a pulsed nanosecond laser with a wavelength of 355 nm, precisely ord…
View article: Photonic integration of uniform GaAs nanowires in hexagonal and honeycomb lattice for broadband optical absorption
Photonic integration of uniform GaAs nanowires in hexagonal and honeycomb lattice for broadband optical absorption Open
We present an experimental approach toward the realization of GaAs nanowires in the form of square, hexagonal, and honeycomb lattices for photonic integration toward enhanced optical properties. We have carried out a design and fabrication…
View article: Fabrication of sub-micrometer periodic nanostructures using pulsed laser interference for efficient light trapping in optoelectronic devices
Fabrication of sub-micrometer periodic nanostructures using pulsed laser interference for efficient light trapping in optoelectronic devices Open
Surface nano-texturing can play an important role for efficiency enhancement of light emission and absorption in optoelectronic devices through reduced surface reflection or enhanced broadband absorption. Periodic and uniform semiconductor…
View article: In-Situ Pulsed Laser Interference Nanostructuring of Semiconductor Surfaces
In-Situ Pulsed Laser Interference Nanostructuring of Semiconductor Surfaces Open
We report the fabrication of periodic one- and two-dimensional nanostructures on semiconductor surfaces utilizing in-situ single-pulse direct laser interference patterning during molecular beam epitaxial growth. A Nd:YAG laser operating at…
View article: In-Situ Pulsed Laser Interference Nanostructuring of Semiconductor Sur-faces
In-Situ Pulsed Laser Interference Nanostructuring of Semiconductor Sur-faces Open
We report the fabrication of periodic one-and two-dimensional nanostructures on semiconductor surfaces utilizing in-situ single-pulse direct laser interference patterning during molecular beam epitaxial growth.A Nd:YAG laser operating at 3…
View article: Direct patterning of periodic semiconductor nanostructures using single-pulse nanosecond laser interference
Direct patterning of periodic semiconductor nanostructures using single-pulse nanosecond laser interference Open
We demonstrate an effective method for fabricating large area periodic two-dimensional semiconductor nanostructures by means of single-pulse laser interference. Utilizing a pulsed nanosecond laser with a wavelength of 355 nm, precisely ord…
View article: Broadband enhancement of light-matter interaction in photonic crystal cavities integrating site-controlled quantum dots
Broadband enhancement of light-matter interaction in photonic crystal cavities integrating site-controlled quantum dots Open
The fabrication of integrated quantum dot (QD)-optical microcavity systems is a requisite step for the realization of a wide range of nanophotonic experiments (and applications) that exploit the ability of QDs to emit nonclassical light, e…
View article: Precise Arrays of Epitaxial Quantum Dots Nucleated by In-Situ Laser Interference for Quantum Information Technology Applications
Precise Arrays of Epitaxial Quantum Dots Nucleated by In-Situ Laser Interference for Quantum Information Technology Applications Open
Precisely ordered arrays of InAs quantum dots are formed on a nanoisland-structured GaAs (100) surface using in-situ laser interference during self-assembled molecularr beam epitaxial growth. Nanoislands induced by single-pulse four-beam l…
View article: Precise Arrays of Epitaxial Quantum Dots Nucleated by In Situ Laser Interference for Quantum Information Technology Applications
Precise Arrays of Epitaxial Quantum Dots Nucleated by In Situ Laser Interference for Quantum Information Technology Applications Open
Precisely ordered arrays of InAs quantum dots are formed on a nanoisland-structured GaAs (100) surface using in situ laser interference during self-assembled molecular beam epitaxial growth. Nanoislands induced by single-pulse four-beam la…
View article: Broadband, wide-angle antireflection in GaAs through surface nano-structuring for solar cell applications
Broadband, wide-angle antireflection in GaAs through surface nano-structuring for solar cell applications Open
We demonstrate broadband and wide-angle antireflective surface nanostructuring in GaAs semiconductors using variable dose electron-beam lithography (EBL). Various designed structures are written with EBL on a positive EB-resist coated GaAs…
View article: Theoretical modelling of single-mode lasing in microcavity lasers via optical interference injection
Theoretical modelling of single-mode lasing in microcavity lasers via optical interference injection Open
The effective manipulation of mode oscillation and competition is of fundamental importance for controlling light emission in semiconductor lasers. Here we develop a rate equation model which considers the spatially modulated gain and spon…
View article: In-situ laser interference patterning of MBE growth surfaces
In-situ laser interference patterning of MBE growth surfaces Open
Single-pulse laser interference is applied to a Molecular Beam Epitaxy growth chamber to achieve in-situ patterning during the growth of III-V materials, with a focus on producing arrays of III-V quantum dots. We will describe the construc…
View article: Control of quality factor in laterally coupled vertical cavities
Control of quality factor in laterally coupled vertical cavities Open
In this work, the authors demonstrate the control of quality factor ( Q ‐factor) is laterally coupled vertical cavities. A 3 μm‐side‐length square cavity directly connected to a 1.5 μm‐width, 10 μm‐length Fabry–Perot (FP) cavity has been f…
View article: Photonic Crystal Cavity-Based Intensity Modulation for Integrated Optical Frequency Comb Generation
Photonic Crystal Cavity-Based Intensity Modulation for Integrated Optical Frequency Comb Generation Open
A simple scheme to generate an integrated, nanoscale optical frequency comb (OFC) is numerically studied. In this study, all optical intensity modulators based on photonic crystal (PhC) cavities are cascaded both in series and parallel. By…
View article: Thermodynamic Processes on a Semiconductor Surface during In-Situ Multi-Beam Laser Interference Patterning
Thermodynamic Processes on a Semiconductor Surface during In-Situ Multi-Beam Laser Interference Patterning Open
Laser interference has been widely used to produce one-dimensional gratings and more recently has shown great potential for two-dimensional patterning. In this paper, we examine by simulation, its application to in-situ patterning during m…
View article: Thermodynamic processes on a semiconductor surface during in‐situ multi‐beam laser interference patterning
Thermodynamic processes on a semiconductor surface during in‐situ multi‐beam laser interference patterning Open
Laser interference has been widely used to produce one‐dimensional gratings and more recently has shown great potential for two‐dimensional patterning. In this study, the authors examine by simulation, its application to in‐situ patterning…
View article: Site-Controlled Single Photon Emitters Fabricated By Near Field Illumination
Site-Controlled Single Photon Emitters Fabricated By Near Field Illumination Open
Many of the most advanced applications of semiconductor quantum dots (QDs) in quantum information technology require a fine control of the QDs’ position and confinement potential, which cannot be achieved with conventional growth technique…
View article: Quantum Dots: Site‐Controlled Single‐Photon Emitters Fabricated by Near‐Field Illumination (Adv. Mater. 21/2018)
Quantum Dots: Site‐Controlled Single‐Photon Emitters Fabricated by Near‐Field Illumination (Adv. Mater. 21/2018) Open
In article number 1705450, Francesco Biccari and co-workers describe a novel and versatile approach for the post-growth fabrication of site-controlled, single-photon-emitting quantum dots. This approach, which deploys the hot spot of a nea…
View article: Site‐Controlled Single‐Photon Emitters Fabricated by Near‐Field Illumination
Site‐Controlled Single‐Photon Emitters Fabricated by Near‐Field Illumination Open
Many of the most advanced applications of semiconductor quantum dots (QDs) in quantum information technology require a fine control of the QDs' position and confinement potential, which cannot be achieved with conventional growth technique…
View article: Dynamical suppression of fluctuations in an interacting nuclear spin bath of a self-assembled quantum dot using multiple pulse nuclear magnetic resonance
Dynamical suppression of fluctuations in an interacting nuclear spin bath of a self-assembled quantum dot using multiple pulse nuclear magnetic resonance Open
Electron spin qubit coherence in quantum dots is ultimately limited by random nuclear spin bath fluctuations. Here we aim to eliminate this randomness by making spin bath evolution deterministic. We introduce spin bath control sequences, w…