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Sebastien Forget - One of the best experts on this subject based on the ideXlab platform.
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comment on Gain Coefficient method for amplified spontaneous emission in thin waveguided film of a conjugated polymer appl phys lett 93 163307 2008
Applied Physics Letters, 2009Co-Authors: Sebastien Chenais, Sebastien ForgetAbstract:Comment on " Gain Coefficient method for amplified spontaneous emission in thin waveguided film of a conjugated polymer " [APL 93, 163307 (2008)]
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Comment on " Gain Coefficient method for amplified spontaneous emission in thin waveguided film of a conjugated polymer " [APL 93, 163307 (2008)]
2008Co-Authors: Sebastien Chenais, Sebastien ForgetAbstract:Comment on " Gain Coefficient method for amplified spontaneous emission in thin waveguided film of a conjugated polymer " [APL 93, 163307 (2008)]
Tilmann E Kuhn - One of the best experts on this subject based on the ideXlab platform.
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calorimetric determination of the solar heat Gain Coefficient g with steady state laboratory measurements
Energy and Buildings, 2014Co-Authors: Tilmann E KuhnAbstract:Abstract The paper describes procedures for the direct calorimetric measurement of the solar heat Gain Coefficient g in detail. g is also called SHGC, solar factor, g-value or total solar energy transmittance TSET. All these terms are used synonymously in this document although there are some differences in the details of the definitions of these properties (e.g. different reference wind conditions or reference solar spectra). The document aims to summarize more than 25 years of experience in g-value testing at Fraunhofer ISE, Freiburg, Germany, which includes many different transparent and translucent building materials ranging from transparent insulation materials to daylighting and solar control systems and active solar energy harvesting facade components like building-integrated PV systems (BIPV) or building-integrated solar thermal collectors (BIST). The document focuses on methods for the calorimetric measurement of g under steady-state laboratory conditions. Transient outdoor measurements are beyond the scope of this paper. It also describes the corresponding error analysis and methods to correct experimentally determined values gexp to reference conditions, if it is not possible to reproduce the reference boundary conditions exactly in the laboratory.
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calorimetric determination of the solar heat Gain Coefficient g with steady state laboratory measurements
Energy and Buildings, 2014Co-Authors: Tilmann E KuhnAbstract:Abstract The paper describes procedures for the direct calorimetric measurement of the solar heat Gain Coefficient g in detail. g is also called SHGC, solar factor, g-value or total solar energy transmittance TSET. All these terms are used synonymously in this document although there are some differences in the details of the definitions of these properties (e.g. different reference wind conditions or reference solar spectra). The document aims to summarize more than 25 years of experience in g-value testing at Fraunhofer ISE, Freiburg, Germany, which includes many different transparent and translucent building materials ranging from transparent insulation materials to daylighting and solar control systems and active solar energy harvesting facade components like building-integrated PV systems (BIPV) or building-integrated solar thermal collectors (BIST). The document focuses on methods for the calorimetric measurement of g under steady-state laboratory conditions. Transient outdoor measurements are beyond the scope of this paper. It also describes the corresponding error analysis and methods to correct experimentally determined values gexp to reference conditions, if it is not possible to reproduce the reference boundary conditions exactly in the laboratory.
Robert G. Harrison - One of the best experts on this subject based on the ideXlab platform.
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Means for easy and accurate measurement of the stimulated Brillouin scattering Gain Coefficient in optical fiber.
Optics letters, 2008Co-Authors: Valerii I Kovalev, Robert G. HarrisonAbstract:We propose and investigate an accurate method for the experimental measurement of the stimulated Brillouin scattering Gain Coefficient in optical fiber. The Gain is extracted from measuring the transmitted pump power at the threshold of stimulated Brillouin scattering (SBS) laser oscillation in a Fabry-Perot cavity formed by Fresnel reflection at the fiber ends. The method is free from a range of uncertainties and difficulties of commonly used approaches and is easy to implement. Experimental evidence of the variation of the SBS Gain Coefficient with numerical aperture of the fiber, first predicted in [Phys. Rev. Lett. 85, 1879 (2000)], is proven.
S Sarikhani - One of the best experts on this subject based on the ideXlab platform.
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Behavioral study of Ar x-ray lasers at 46.9 nm based on model of geometrically dependent Gain Coefficient
Optik, 2019Co-Authors: A. Hariri, S SarikhaniAbstract:Abstract There are many experimental measurements appeared in the literature, where the researchers reported their measured amplified spontaneous emission (ASE) output energies versus medium excitation lengths. In this paper we report on the ASE analyses, made based on using intensity rate equation along with the geometrically dependent Gain Coefficient (GDGC) model, for different measurements carried out in different laboratories under different experimental conditions. We show that the deduced Gain Coefficients follow a general equation of g0ν° (cm−1) = 0.37 + 11.51/lAMP, where lAMP is the medium excitation length. For this study at least 13 experimental measurements were analyzed. The method also revealed that we can obtain the behavior of Gain Coefficient with respect to input current. The optimum operational current is 30 kA, and the calculated intrinsic spectral linewidth for i = 21 kA is 55.67 mA. With the GDGC model, consequently, it can be concluded that Ne-like Ar x-ray lasers are unified, and method simplifies greatly the analyses of complicated systems.
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theoretical study of amplified spontaneous emission in ne like se x ray laser spectral linewidth and Gain Coefficient
Optical and Quantum Electronics, 2016Co-Authors: A. Hariri, S SarikhaniAbstract:A theoretical study for the spectral linewidth behavior of the Se X-ray laser at 206.4 A has been made to obtain the intrinsic linewidth. For a Se target of 6.3 cm in length it is shown that the amplified spontaneous emission (ASE) initiates at the threshold length of z th = 0.13 cm. The method gives an excellent agreement with the measurements, leading to 44 mA intrinsic linewidth for Se X-ray lasers at this wavelength. The calculation is also extended for another Se X-ray transition at 209.6 A. We further confirm that the calculated linewidth follows a Voigt profile and its sensitivity to the collision broadening is examined. For the approach the geometrically dependent Gain Coefficient (GDGC) model is used. The results of the deduced Gain parameters obtained from the experiment related to the target of 6.3 cm in length is used to calculate the Gain profile explaining Gain Coefficients for samples of different excitation lengths such as 1.12 and 2.24 cm in length corresponding to the first report on the Se X-ray laser. The plot of Gain Coefficient versus target length for different measurements confirms that the GDGC model is able to unify Se X-ray lasers. Finally, a summary of the past reported analyses for different types of self terminating lasers will be given, where it further verifies the validity of the GDGC model to be used in different types of laser media.
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application of the geometrically dependent Gain Coefficient model to describe amplified spontaneous emission behavior in organic solid laser materials theoretical considerations
Journal of Modern Optics, 2015Co-Authors: A. Hariri, S SarikhaniAbstract:A model of geometrically dependent Gain Coefficient is applied to small-sized media to explain the amplified spontaneous emission intensity and bandwidth reduction along the light propagation direction. The model is used for two typical experimental examples of photo-pumped pyrromethene 567-doped polymer and BuEH-PPV conjugated polymer waveguides, and excellent consistency with the measurements is obtained. The calculations are performed both analytically and numerically, where the effect of saturation on the Gain Coefficient for the homogeneously broadened line-shape upon using a 4-level system is considered.
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Study of the amplified spontaneous emission spectral width and Gain Coefficient for a KrF laser in unsaturated and saturated conditions
Laser Physics Letters, 2013Co-Authors: A. Hariri, S SarikhaniAbstract:On the basis of a model of a geometrically dependent Gain Coefficient, the amplified spontaneous emission (ASE) spectral width was calculated analytically for the nearly resonant transition of ν ~ ν0, and also numerically for a wide range of transition frequencies. For this purpose, the intensity rate equation was used under unsaturated and saturated conditions. For verifying the proposed model, reported measurements of the ASE energy versus the excitation length for a KrF laser were used. For the excitation length of l = 84 cm corresponding to single-path propagation, the ASE spectral width for the homogeneously broadened transition was calculated to be 6.28 A, to be compared with the measured 4.1 A spectral width reported for a KrF oscillator utilizing a two-mirror resonator. With the Gain parameters obtained from the ASE energy measurements, the unsaturated and saturated Gain Coefficients for l = 84 cm were calculated to be 0.042 cm−1 and 0.014 cm−1, respectively. These values of the Gain Coefficient are comparable to but slightly lower than the measured Gain Coefficient for laser systems of 80–100 cm excitation lengths reported from different laboratories.
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theoretical study of amplified spontaneous emission using a model based on a geometrically dependent Gain Coefficient
Journal of Optics, 2013Co-Authors: A. Hariri, S SarikhaniAbstract:It is shown that a model based on a geometrically dependent Gain Coefficient (GDGC), which is characterized by Gain parameters (m?, , b), introduces a powerful method to describe amplified spontaneous emission (ASE) intensity behavior and its bandwidth reduction when the ASE is propagating along the z-direction. The model also gives correct predictions for unsaturated and saturated Gain Coefficients and the frequency dependence of the ASE output intensity in a given laser system. For the calculation, the GDGC model in saturated and unsaturated conditions along with the intensity rate equation were applied, and for verification of the model the reported ASE intensity measurements and the measured bandwidth reduction in KrF lasers were utilized. The present model will have applications in any type of pulsed laser system of different active media and different dimensions without going through complicated analysis or utilizing heavy computer numerical computations. Details of the present approach will be given and the excellent agreement with the available and typical experimental measurements for KrF lasers confirms the validity of the proposed GDGC model.
L A Cury - One of the best experts on this subject based on the ideXlab platform.
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Gain Coefficient method for amplified spontaneous emission in thin waveguided film of a conjugated polymer
Applied Physics Letters, 2008Co-Authors: Ive Silvestre, P W B Marques, M Valadares, L A CuryAbstract:A method based on the unidimensional Gain equation has been developed in order to fit the experimental data due to amplification of spontaneous emission in a thin film of conjugated polymer waveguide. The results have confirmed not only a dependence of the Gain Coefficient on the laser intensity but also on the length of the excitation laser stripe. The results are presented as a function of the average intensity in W/cm2, which is a manner to express the threshold intensity for a direct comparison between different materials, independent of the setup used.