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We present a novel single-photon-source based on the emission of a semiconductor quantum dot embedded in a single-mode photonic wire. This geometry ensures a very large coupling (> 95%) of the spontaneous emission to the guided mode. Numerical simulations show that a photon collection efficiency as large as 90% can be obtained for engineered nanowires with a tapered tip and a metallic bottom mirror...
The line-width of the optical transitions in quantum dots is studied theoretically on the basis of the electron coupling to the longitudinal optical phonons in polar semiconductors. With using the self-consistent Born approximation to the electronic self-energy, we are able to reproduce one of the main experimental results obtained on CdSe and CuBr quantum dots, namely the linear dependence of the...
P-doped and undoped quantum dot (QD) semiconductor optical amplifiers (SOA) are compared regarding their static and dynamic characteristics. The amplified spontaneous emission and gain curves are evaluated for p-doped and undoped devices exhibiting a gain per length of 10 dB/mm and 7 dB/mm, respectively. P-doped and undoped devices having 22 dB and 23.5 dB chip gain, respectively, were compared in...
In this paper, based on 8-band k.p method, we study the infrared wavelength absorption through the conduction subbands of InAs/GaAs pyramidal shape quantum dots (PSQDs) using finite difference method. Considering homogeneous and inhomogeneous broadening effects we design an asymmetric multiple barrier resonant tunnelling (AMBRT) quantum dot infrared photodetector (QDIP) for lower dark current at lambda=10...
The following topics are dealt with: supercontinuum generation; optical fiber networks; optical communication equipments; quantum dots; nonlinear optics; optical amplifiers; optical fibers; signal processing and cryptography; optical switching; lasers; metamaterials; optical elements; and plasmonics.
In this paper, the evidence of a polarized and room temperature single photon emission from wet-chemically synthesized colloidal dot-in-a-rod is reported. The time and polarization resolved measurements clearly indicate a high degree of linear polarization and a lifetime of ~11 ns. We report also about a viable strategy to develop single photon sources with polarization control for quantum cryptography.
Quantum-dot twin-stripe lasers have been fabricated and characterized. Dynamic features have been observed indicating regimes of chaotic operation that make these lasers suitable for chaotic-encryption application.
Summary form only given. One-dimensional nanostructures are desirable in modern technology for their potential applications as the smallest possible carriers for electrons or plasmonic signals. The ability to direct the signal from source to destination could have major implications in the fields of nanoelectronics and photonics. However, one of the major challenges facing the application of these...
Forster resonant energy transfer (FRET) has been investigated in two different quantum dot (QD) structures. Colloidal CdTe QDs of two different sizes act as energy donors and acceptors. They have been deposited in a mixed monolayer and a separate donor/acceptor layer structure. The optical properties of these structures have been analysed by steady-state absorption and photoluminescence (PL) spectroscopy,...
We present a formalism for calculating the multiple-quantum-dot-photon dynamics in coupled-cavity photonic crystal slab systems by projecting the Hamiltonian onto non-orthogonal photon quasimodes and applying the quantum jump technique. We apply this approach to the correlated emission by two quantum dots and demonstrate the importance of the non-orthogonality of the quasimodes.
Semiconductor nanocrystals have unique optical properties that make them promising alternatives to traditional dyes in many luminescence based analytical techniques. An overview of the more relevant progresses in the application of quantum dots (QDs) as analytical probes in optical fibre sensing and imaging application will be addressed. Experimental results regarding the use of QDs as self-referenced...
The effects of the electrical parasitics and external optical reflections on the dynamic regimes and spectral properties of Fabry-Perot and Distributed Bragg Reflector monolithic mode-locked laser diodes are investigated numerically. Reduction of the range of stable mode-locking by the screening of the applied electric field by photocarriers accumulated due to the finite absorber circuit response...
In this paper we analyze, based on numerical simulations, the dynamics of semiconductor devices incorporating quantum dots (QDs). In particular we emphasize the unique ultrafast carrier dynamics occurring between discrete QD bound states, and its influence on QD semiconductor optical amplifiers (SOAs). Also the possibility of realizing an all-optical regenerator by incorporating a QD absorber section...
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