Artifact removal in FD-OCT with a B-M mode scanning technique : Condition on the transverse step

One of the main drawbacks of Fournier-domain optical coherence tomography is its inability to differentiate between positive and negative locations relative to the zero-delay position. In the recently proposed B-M mode scanning technique, these artifacts are removed by introducing a transverse modulation between successive A-scans followed by a Fourier filtering in the transverse direction. This paper deals with the relation between the transverse step size and the efficency of artifact removal. This relation is illustrated with measurements performed on an onion with different transverse step sizes and different focusing optics. These experimental results are used to support a proposed criterion for the transverse step. The criterion aims at insuring efficient artifact removal while limiting the amount of oversampling in the transverse scan.Un des principaux probl\ue8mes pos\ue9s par la tomographie par coh\ue9rence optique \ue0 domaine de Fourier (TCO-DF) est son incapacit\ue9 \ue0 faire la diff\ue9rence entre les endroits positifs ou n\ue9gatifs par rapport \ue0 la position de d\ue9lai z\ue9ro. Dans la technique de balayage en mode B-M r\ue9cemment propos\ue9, ces art\ue9facts sont \ue9limin\ue9s en introduisant une modulation transversale entre des A-scans successifs, suivie d\u2019un filtrage Fourier dans la direction transversale. Dans le pr\ue9sent article, on traite de la relation entre la taille du pas transversal et l\u2019efficacit\ue9 de l\u2019\ue9limination des art\ue9facts. Cette relation est illustr\ue9e gr\ue2ce \ue0 des mesures r\ue9alis\ue9es sur un oignon avec diff\ue9rentes tailles de pas transversal et diff\ue9rentes optiques de focalisation. Les r\ue9sultats exp\ue9rimentaux sont utilis\ue9s pour appuyer un crit\ue8re propos\ue9 pour le pas transversal. Le crit\ue8re vise \ue0 assurer une \ue9limination efficace des art\ue9facts tout en limitant la quantit\ue9 de recouvrement du balayage transversal.Peer reviewed: YesNRC publication: Ye

Calculation of the energy spectrum of a two-electron spherical quantum dot

We study the energy spectrum of the two-electron spherical parabolic quantum dot using the exact Schroedinger, the Hartree-Fock, and the Kohn-Sham equations. The results obtained by applying the shifted-1/N method are compared with those obtained by using an accurate numerical technique, showing that the relative error is reasonably small, although the first method consistently underestimates the correct values. The approximate ground-state Hartree-Fock and local-density Kohn-Sham energies, estimated using the shifted-1/N method, are compared with accurate numerical self-consistent solutions. We make some perturbative analyses of the exact energy in terms of the confinement strength, and we propose some interpolation formulae. Similar analysis is made for both mean-field approximations and interpolation formulae are also proposed for these exchange-only ground-state cases.Comment: 18 pages, LaTeX, 2 figures-ep

Artifact removal in Fourier-domain optical coherence tomography with a piezoelectric fiber stretcher

Peer reviewed: YesNRC publication: Ye

Common Path swept-source OCT interferometer with artifact removal

Peer reviewed: YesNRC publication: Ye

Artifacts removal with a piezoelectric fiber stretcher in Fourier domain OCT

Peer reviewed: YesNRC publication: Ye

On the speckle size in optical coherence tomography

Peer reviewed: YesNRC publication: Ye

Magnetic field dependence of the exciton energy in a quantum disk

The groundstate energy and binding energy of an exciton, confined in a^M quantum disk, are calculated as a function of an external magnetic field. The confinement potential is a hard wall of finite height. The diamagnetic shift is investigated for magnetic fields up to 40$T$. Our results are applied to $In_{y}Al_{1-y}As/Al_{x}Ga_{1-x}As$ self-assembled quantum dots and very good agreement with experiments is obtained. Furthermore, we investigated the influence of the dot size on the diamagnetic shift by changing the disk radius. The exciton excited states are found as a function of the magnetic field. The relative angular momentum is not a quantum number and changes with the magnetic field strength.Comment: 10 pages, 17 figure

Consensus standards for acquisition, measurement, and reporting of intravascular optical coherence tomography studies

Objectives: The purpose of this document is to make the output of the International Working Group for Intravascular Optical Coherence Tomography (IWG-IVOCT) Standardization and Validation available to medical and scientific communities, through a peer-reviewed publication, in the interest of improving the diagnosis and treatment of patients with atherosclerosis, including coronary artery disease. Background: Intravascular optical coherence tomography (IVOCT) is a catheter-based modality that acquires images at a resolution of ∼10 μm, enabling visualization of blood vessel wall microstructure in vivo at an unprecedented level of detail. IVOCT devices are now commercially available worldwide, there is an active user base, and the interest in using this technology is growing. Incorporation of IVOCT in research and daily clinical practice can be facilitated by the development of uniform terminology and consensus-based standards on use of the technology, interpretation of the images, and reporting of IVOCT results. Methods: The IWG-IVOCT, comprising more than 260 academic and industry members from Asia, Europe, and the United States, formed in 2008 and convened on the topic of IVOCT standardization through a series of 9 national and international meetings. Results: Knowledge and recommendations from this group on key areas within the IVOCT field were assembled to generate this consensus document, authored by the Writing Committee, composed of academicians who have participated in meetings and/or writing of the text. Conclusions: This document may be broadly used as a standard reference regarding the current state of the IVOCT imaging modality, intended for researchers and clinicians who use IVOCT and analyze IVOCT data