Search results for "fabry"

Theoretical gain spectrum of coherently pumped mid-infrared Fabry-Pérot lasers

1992

Abstract We study the gain spectrum of a coherently pumped mid-infrared laser which operates in a linear-cavity (Fabry-Perot), using a three-level density matrix theory. Arbitrary pump and emission field strengths as well as pressure and Doppler broadening are considered. A new strong directional gain asymmetry is found, which is related to the presence of two counterpropagating components in the standing-wave generated field. Gain lineshapes in a wide range of operating conditions are obtained and analysed.

Subwavelength sound screening by coupling space-coiled Fabry-Perot resonators

2017

We explore broadband and omnidirectional low frequency sound screening based on locally resonant acoustic metamaterials. We show that the coupling of different resonant modes supported by Fabry-Perot cavities can efficiently generate asymmetric lineshapes in the transmission spectrum, leading to a broadband sound opacity. The Fabry-Perot cavities are space-coiled in order to shift the resonant modes under the diffraction edge, which guaranty the opacity band for all incident angles. Indeed, the deep subwavelength feature of the cavities leads to avoid diffraction that have been proved to be the main limitation of omnidirectional capabilities of locally resonant perforated plates. We experim…

Resilience of singlet-state extraction against non-optimal resonance conditions

2008

We have recently presented a protocol for extracting the singlet state of two non-interacting high-dimensional spins through post-selection of the internal state of interaction mediators sent in succession [F. Ciccarello et al., arXiv:0710.3855v1]. The scheme requires each mediator's wavevector to obey appropriate resonance conditions. Here we show the robustness of the scheme in the realistic case where such conditions are not sharply fulfilled.

Experiments on optical fiber interferometers and laser modes

1992

Three experiments on optical fiber interferometers, suitable for a teaching laboratory, are described. The guiding characteristics of single mode optical fibers enable simple interferometry experiments with large path differences to be carried out easily. These experiments show that the fringe visibility exhibits a periodic dependence on the path difference when using a multilongitudinal mode HeNe laser. A simple model can be used to explain this dependence in terms of the mode spectrum of the laser.

Steady-state emission and stability of a single-mode two-level Fabry-Perot cavity laser

1997

Abstract An analytical steady-state solution for a single-mode homogeneously-broadened two-level Fabry-Perot laser, valid for any field intensity, cavity detuning and level-population decay rates, is obtained. A power-series expansion of this solution allows to perform a linear stability analysis which reveals the existence of two Hopf bifurcations instead of one as in unidirectional ring lasers. These bifurcations delimit the domain of unstable emission of the laser with respect to small perturbations. The instability threshold for hard-mode excitation is higher than in a ring laser, although introduction of a small definite detuning makes them similar. The time-dependent behaviour above t…

Analytical description of resonances in Fabry–Perot and whispering gallery mode resonators

2021

Whispering gallery mode optical resonators have attracted attention due to their simplicity and applicability for sensing. In this paper, analytical formulas are provided that describe resonance conditions in optical resonators. Basic terms (resonance wavelengths and frequencies, free spectral range, Q -factor, summation principle of Q -factors of various processes, finesse, etc.) are introduced. A description of interference of an infinite number of waves of progressively smaller amplitudes and equal phase differences is given. A description of a Fabry–Perot resonator with nonequal reflection coefficients is also given as well as analysis of all-pass and add-drop optical filters. The prese…

Brain structural alterations in Fabry disease: ROI-based and voxel-based analyses of diffusion tensor imaging parameters

2007

Fabry-Pérot Interferometer : construction, calibration and developement

2015

The work presented in this thesis concentrates on the construction and development of a Fabry-Perot Interferometer (FPI). Resonance ionization spectroscopy (RIS) is a powerful technique for the extraction of nuclear structure, namely nuclear spins, moments and changes in mean-square charge radii. However, due to the pulsed nature of the laser, the technique may be limited by the laser linewidth to low resolution spectroscopy. This thesis presents the construction and characterization of a Fabry-Perot Interferometer in order to measure the laser linewidth and to calibrate the wavelength of a pulsed Ti:Sapphire laser in "Narrowband" mode (<1 GHz). The FPI has been directly utilized in the mea…

Enzyme replacement therapy with agalsidase alfa in pregnant women with Fabry disease

2009

A family with various symptomatology suggestive of Anderson-Fabry disease and a genetic polymorphism of alpha galactosidase A gene.

2014

Background: Anderson/Fabry disease expresses a wide range of clinical variability in patients that it is possible to explain referring to a genetic variability with numerous mutations described in the literature (more than 600). Methods: We report some clinical cases of some members of a Sicilian family to express phenotypical variability of this disease in subjects with the same genetic mutation. Results: The first case was a 59-year-old female. Brain MRI revealed right frontal periventricular white matter of likely vascular-degenerative origin. The proband's alpha galactosidase A activity was 3.7. nmol/mL/h. Molecular genetics revealed a polymorphism: - 10 C. &gt;. T; IVS 2-76_80del5; IVS…