Search results for " Cavity"

Quantum groups and quantum complete integrability: Theory and experiment

2008

Role of field losses on the Risken?Nummedal?Graham?Haken laser instability: application to erbium-doped fibre lasers

2003

We analyse the effect of both distributed and localised losses in a laser cavity on the Risken–Nummedal–Graham–Haken multimode instability. For two-level lasers, distributed losses are found to have a negligible influence on the instability conditions as long as they remain below 10 dB, a value hardly ever exceeded under common experimental conditions. If one keeps raising the distributed loss above that value, finally the uniform-field-limit results are recovered: localised loss becomes less and less important, and in the limit does not enter at all. In contrast, for three-level lasers – in particular for erbium-doped fibre lasers – distributed losses are found to have a profound quantitat…

Atomic teleportation via cavity QED and position measurements: efficiency analysis

2008

We have recently presented a novel protocol to teleport an unknown atomic state via cavity QED and position measurements. Here, after a brief review of our scheme, we provide a quantitative study of its efficiency. This is accomplished by an explicit description of the measurement process that allows us to derive the fidelity with respect to the atomic internal state to be teleported.

When Casimir meets Kibble–Zurek

2012

Verification of the dynamical Casimir effect (DCE) in optical systems is still elusive due to the very demanding requirements for its experimental implementation. This typically requires very fast changes in the boundary conditions of the problem. We show that an ensemble of two-level atoms collectively coupled to the electromagnetic field of a cavity, driven at low frequencies and close to a quantum phase transition, stimulates the production of photons from the vacuum. This paves the way for an effective simulation of the DCE through a mechanism that has recently found experimental demonstration. The spectral properties of the emitted radiation reflect the critical nature of the system an…

Photon Production from the Vacuum Close to the Superradiant Transition: Linking the Dynamical Casimir Effect to the Kibble-Zurek Mechanism

2012

The dynamical Casimir effect (DCE) predicts the generation of photons from the vacuum due to the parametric amplification of the quantum fluctuations of an electromagnetic field. The verification of such an effect is still elusive in optical systems due to the very demanding requirements of its experimental implementation. We show that an ensemble of two-level atoms collectively coupled to the electromagnetic field of a cavity, driven at low frequencies and close to a quantum phase transition, stimulates the production of photons from the vacuum. This paves the way to an effective simulation of the DCE through a mechanism that has recently found experimental demonstration. The spectral prop…

Therapiemonitoring mittels 2-[18F]-FDG-Positronenemissionstomographie nach neoadjuvanter Strahlenbehandlung des Mundhöhlenkarzinoms

2001

Die Kombination strahlentherapeutischer und chirurgischer Behandlungsschritte beim Mundhohlenkarzinom erfordert eine fruhe, objektive Bewertung des Bestrahlungserfolgs. Schlechtes radiotherapeutisches Ansprechverhalten verlangt die moglichst umgehende chirurgische Sanierung auch bei hohem Operations- und Narkoserisiko. Eine deutliche Remission unter Strahlentherapie kann dagegen die Fortsetzung der Bestrahlungsbehandlung begrunden. Die vorliegende Studie untersucht daher die Bewertung des Bestrahlungserfolgs anhand der durch Positronenemissionstomographie (PET) bestimmten Glukosestoffwechselaktivitat.

Resection of verrucous squamous cell carcinoma of the nasal cavity using advanced radiofrequency

2008

"Osteolipoma of buccal mucosa: Case report and literature review"

2016

Osteolipoma affecting oral cavity is indeed rare. We hereby report a case of osteolipoma affecting buccal mucosa. A review of literature of osteolipoma of oral cavity, particularly on radiographic/imaging findings was done. Only 16 cases of Osteolipoma of oral cavity are reported in the literature. The radiographic findings of our case, i.e. multiple dense homogenous radio-opaque structures was reported earlier only in one case [out of 16] of osteolipoma of oral cavity. Key words:Lipoma, osteolipoma, panoramic radiography, radio-opaque, radiography.

Pharmacological approach to the pro- and anti-inflammatory effects of Ranunculus sceleratus L.

2003

Ranunculus sceleratus is a widespread species with unique toxicological and pharmacological activities. The present study seeks to assess this species' ability, both in vitro and in vivo, to modulate processes involved in inflammations. To this end, different extracts from the aerial parts of the plant were tested in several models of acute inflammation induced by tetradecanoylphorbol acetate (TPA), arachidonic acid (AA), and carrageenan, as well as in two models of delayed hypersensitivity induced by oxazolone and dinitrofluorobencene (DNFB). The extracts were also assayed in models of eicosanoid and elastase release by intact cells. When tested in vivo, all of the extracts showed anti-inf…

Mechanisms and predictors of chronic facial pain in lateral medullary infarction

2001

The purpose of this study was to identify clinical predictors and anatomical structures involved in patients with pain after dorsolateral medullary infarction. Eight out of 12 patients (67%) developed poststroke pain within 12 days to 24 months after infarction. The pain occurred in the ipsilateral face (6 patients) and/or the contralateral limbs and trunk (5 patients, 3 of whom also had facial pain). Ipsilateral facial pain was significantly correlated with lower medullary lesions, including those of the spinal trigeminal tract and/or nucleus, as documented by magnetic resonance imaging. The R2 blink reflex component was abnormal only in patients with facial pain. Likewise, pain and temper…