Effects of Dislocation Filtering Layers on Optical Properties of Third Telecom Window Emitting InAs/InGaAlAs Quantum Dots Grown on Silicon Substrates.

Integrating light emitters based on III-V materials with silicon-based electronics is crucial for further increase in data transfer rates in communication systems since the indirect bandgap of silicon prevents its direct use as a light source. We investigate here InAs/InGaAlAs quantum dot (QD) structures grown directly on 5° off-cut Si substrate and emitting light at 1.5 μm, compatible with established telecom platform.

Luminescent Properties of Phosphonate Ester-Supported Neodymium(III) Nitrate and Chloride Complexes.

This study examines the synthesis of two geminal bisphosphonate ester-supported Ln complexes [Ln()(NO)] (Ln = Nd (), La ()) and optical properties of the neodymium(III) complex. These results are compared to known mono-phosphonate ester-based Nd complexes [Nd(/)X] (X = NO, n = 1; Cl, n = 2) (-). The optical properties of Nd compounds are determined by micro-photoluminescence (µ-PL) spectroscopy which reveals three characteristic metal-centered emission bands in the NIR region related to transitions from F excited state.

Temperature dependence of refractive indices of AlGaAs and InAlGaAs in the telecommunication spectral range.

In this work, we determine the temperature dependence of refractive indices of InAlGaAs and AlGaAs semiconductor alloys at telecommunication wavelengths in the range from room temperature down to 10 K. For that, we measure the temperature-dependent reflectance of two structures: with an AlGaAs/GaAs distributed Bragg reflector (DBR) designed for 1.3 µm and with an InAlGaAs/InP DBR designed for 1.

Steering coherence in quantum dots by carriers injection via tunneling.

Coherent control is a key experimental technique for quantum optics and quantum information processing. We demonstrate a new degree of freedom in coherent control of semiconductor quantum dot (QD) ensembles operating at room temperature using the tunneling injection (TI) processes in which charge carriers tunnel directly from a quantum well reservoir to QD confined states. The TI scheme was originally proposed and implemented to improve QD lasers and optical amplifiers, by providing a direct injection path of cold carriers thereby eliminating the hot carrier injection problem which enhances gain nonlinearity.

Optical and Spin Properties of NV Center Ensembles in Diamond Nano-Pillars.

Nitrogen-vacancy (NV) color centers in diamond are excellent quantum sensors possessing high sensitivity and nano-scale spatial resolution. Their integration in photonic structures is often desired, since it leads to an increased photon emission and also allows the realization of solid-state quantum technology architectures. Here, we report the fabrication of diamond nano-pillars with diameters up to 1000 nm by electron beam lithography and inductively coupled plasma reactive ion etching in nitrogen-rich diamonds (type Ib) with [100] and [111] crystal orientations.

Spin memory effect in charged single telecom quantum dots.

Single InP-based quantum dots emitting in the third telecom window are probed quasi-resonantly in polarization-resolved microphotoluminescence experiments. For charged quantum dots we observe negative circular polarization being a fingerprint of the optical spin writing of the carriers within the quantum dots. The investigated quantum dots have a very dense ladder of excited states providing relatively easy quasi-resonant optical excitation, and together with telecom wavelengths emission they bring quantum gates and memories closer to compatibility with fiber-optic communication.

Spin memory effect in charged single telecom quantum dots: erratum.

This erratum corrects the value of the wetting layer thickness provided in our Article [Opt. Express29, 34024 (2021)10.1364/OE.

Influence of surface termination of ultrananocrystalline diamond films coated on titanium on response of human osteoblast cells: A proteome study.

Successful osseointegration, i.e. the fully functional connection of patient's bone and artificial implant depends on the response of the cells to the direct contact with the surface of the implant.

Azido-Functionalized Aromatic Phosphonate Esters in POSS-Cage-Supported Lanthanide Ion (Ln = La, Nd, Dy, Er) Coordination.

Within this work, a modified preparation of diethyl 4-azidobenzylphosphonate () is presented and the family of 4- or 4'-azido-substituted aromatic phosphonate esters is increased by three new ligand platforms: diisopropyl 4-azidobenzylphosphonate (), diisopropyl ((4'-azido-[1,1'-biphenyl]-4-yl)methyl)phosphonate (), and diisopropyl 4-azido-2,3,5,6-tetrafluorobenzylphosphonate (), which exhibit an anomalous splitting of the N stretching vibrations. Subsequent coordination to the generated POSS (polyhedral oligomeric silsesquioxane)-cage-supported lanthanide precursors [(Ln{POSS})(THF)] (-) (Ln = La, Nd, Dy, Er; R = Bu, Ph; = 0, 1) yields complexes of the general formula [Ln{POSS}(-)()(THF)] (-) ( = 2, 3; = 0, 1; = 0-2) retaining the azide unit for future semiconductor surface immobilization. Because the latter compounds are mostly oils or viscous waxes, preliminary solution-state structure elucidations via DOSY-ECC-MW estimations have been carried out which are in accordance with H NMR integral ratios as well as solid-state structures, where available.

Magneto-Optical Characterization of Trions in Symmetric InP-Based Quantum Dots for Quantum Communication Applications.

Magneto-optical parameters of trions in novel large and symmetric InP-based quantum dots, uncommon for molecular beam epitaxy-grown nanostructures, with emission in the third telecom window, are measured in Voigt and Faraday configurations of an external magnetic field. The diamagnetic coefficients are found to be in the range of 1.5-4 μeV/T, and 8-15 μeV/T, respectively out-of-plane and in-plane of the dots.

Fabrication and Characterization of Single-Crystal Diamond Membranes for Quantum Photonics with Tunable Microcavities.

The development of quantum technologies is one of the big challenges in modern research. A crucial component for many applications is an efficient, coherent spin-photon interface, and coupling single-color centers in thin diamond membranes to a microcavity is a promising approach. To structure such micrometer thin single-crystal diamond (SCD) membranes with a good quality, it is important to minimize defects originating from polishing or etching procedures.

Functionalised phosphonate ester supported lanthanide (Ln = La, Nd, Dy, Er) complexes.

A series of phosphonate ester supported lanthanide complexes bearing functionalities for subsequent immobilisation on semiconductor surfaces are prepared. Six phosphonate ester ligands (L1-L6) with varying aromatic residues are synthesised. Subsequent complexation with lanthanide chloride or -nitrate precursors (Ln = La, Nd, Dy, Er) affords the corresponding mono- or dimeric lanthanide model complexes [LnX3(L1-L3 or L5-L6)3]n (X = NO3, Cl; n = 1 (Nd, Dy, Er), 2 (La, Nd)) or [LnCl2Br(L4-Br)2(L4-Cl)]n (n = 1 (Nd, Dy, Er), 2 (La, Nd)) (1-32).

Novel Ultra Localized and Dense Nitrogen Delta-Doping in Diamond for Advanced Quantum Sensing.

We introduce and demonstrate a new approach for nitrogen-vacancy (NV) patterning in diamond, achieving a deterministic, nanometer-thin, and dense delta-doped layer of negatively charged NV centers in diamond. We employed a pure nitridation stage using microwave plasma and a subsequent diamond overgrowth. We present the highest reported nitrogen concentration in a delta-doped layer (1.

Carrier transfer efficiency and its influence on emission properties of telecom wavelength InP-based quantum dot - quantum well structures.

We investigate a hybrid system containing an InGaAs quantum well (QW), separated by a thin 2 nm InGaAlAs barrier from 1.55 µm emitting InAs quantum dots (QDs), grown by molecular beam epitaxy on an InP substrate. Photoreflectance and photoluminescence (PL) spectroscopies are used to identify optical transitions in the system, with support of 8-band kp modelling.

Acceleration of the nonlinear dynamics in p-doped indium phosphide nanoscale resonators.

We demonstrated a twofold acceleration of the fast time constant characterizing the recovery of a p-doped indium-phosphide photonic crystal all-optical gate. Time-resolved spectral analysis is compared to a three-dimensional drift-diffusion model for the carrier dynamics, demonstrating the transition from the ambipolar to the faster minority carrier dominated diffusion regime. This opens the perspective for faster yet efficient nanophotonic all-optical gates.

Strong attachment of circadian pacemaker neurons on modified ultrananocrystalline diamond surfaces.

Diamond is a promising material for a number of bio-applications, including the fabrication of platforms for attachment and investigation of neurons and of neuroprostheses, such as retinal implants. In the current work ultrananocrystalline diamond (UNCD) films were deposited by microwave plasma chemical vapor deposition, modified by UV/O3 treatment or NH3 plasma, and comprehensively characterized with respect to their bulk and surface properties, such as crystallinity, topography, composition and chemical bonding nature. The interactions of insect circadian pacemaker neurons with UNCD surfaces with H-, O- and NH2-terminations were investigated with respect to cell density and viability.

Rabi oscillations and self-induced transparency in InAs/InP quantum dot semiconductor optical amplifier operating at room temperature.

We report direct observations of Rabi oscillations and self-induced transparency in a quantum dot optical amplifier operating at room temperature. The experiments make use of pulses whose durations are shorter than the coherence time which are characterized using Cross-Frequency-Resolved Optical Gating. A numerical model which solves the Maxwell and Schrödinger equations and accounts for the inhomogeneously broadened nature of the quantum dot gain medium confirms the experimental results.

Single-photon emission from single InGaAs/GaAs quantum dots grown by droplet epitaxy at high substrate temperature.

The authors report single-photon emission from InGaAs quantum dots grown by droplet epitaxy on (100) GaAs substrates using a solid-source molecular beam epitaxy system at elevated substrate temperatures above 400°C without post-growth annealing. High-resolution micro-photoluminescence spectroscopy exhibits sharp excitonic emissions with lifetimes ranging from 0.7 to 1.

Extreme nonlinearities in InAs/InP nanowire gain media: the two-photon induced laser.

We demonstrate a novel laser oscillation scheme in an InAs / InP wire-like quantum dash gain medium. A short optical pulse excites carriers by two photon absorption which relax to the energy levels providing gain thereby enabling laser oscillations. The nonlinear dynamic interaction is analyzed and quantified using multi-color pump-probe measurements and shows a highly efficient nonlinear two photon excitation process which is larger by more than an order of magnitude compared to common quantum well and bulk gain media.

Complex characterization of short-pulse propagation through InAs/InP quantum-dash optical amplifiers: from the quasi-linear to the two-photon-dominated regime.

We describe direct measurements at a high temporal resolution of the changes experienced by the phase and amplitude of an ultra-short pulse upon propagation through an inhomogenously broadened semiconductor nanostructured optical gain medium. Using a cross frequency-resolved optical gating technique, we analyze 150 fs-wide pulses propagating along an InP based quantum dash optical amplifier in both the quasi-linear and saturated regimes. For very large electrical and optical excitations, a second, trailing peak is generated and enhanced by a unique two-photon-induced amplification process.