scholarly journals Upconversion assisted self-pulsing in a high-concentration erbium doped fibre laser

Open Physics ◽  
2010 ◽  
Vol 8 (2) ◽  
Author(s):  
Sergey Sergeyev ◽  
Kieran O’Mahoney ◽  
Sergei Popov ◽  
Ari Friberg
Keyword(s):  
Experimental Data ◽  
Signal Intensity ◽  
Fibre Laser ◽  
Intensity Noise ◽  
Statistical Nature ◽  
High Concentration ◽  
New Model ◽  
Erbium Ions ◽  
Erbium Doped ◽  
Good Agreement

AbstractWe report results on experimental and theoretical characterisation of self-pulsing in high concentration erbium doped fibre laser which is free from erbium clusters. Unlike previous models of self-pulsing accounting for pair-induced quenching (PIQ) on the clustered erbium ions, new model has been developed with accounting for statistical nature of the excitation migration and upconversion and resonance-like pumpto-signal intensity noise transfer. The obtained results are in a good agreement with the experimental data.

Analysis and Validation of Cutting Forces Prediction Models in Micromachining

2006 ◽  
Vol 526 ◽  
pp. 13-18 ◽  
Author(s):  
H. Perez ◽  
Antonio Vizan Idoipe ◽  
J. Perez ◽  
J. Labarga
Keyword(s):  
Experimental Data ◽  
Cutting Force ◽  
Cutting Forces ◽  
Prediction Models ◽  
Precision Machining ◽  
New Model ◽  
Proposed Model ◽  
On Line ◽  
Machine Control ◽  
Good Agreement

Many investigations have been developed related to precision machining with features in the millimetre scale. In this paper different cutting force models for micromilling are analyzed and compared. A new model based on specific cutting force that also considers run-out errors has been developed. The estimated cutting forces obtained with this model had good agreement with the experimental data. Also, the proposed model allows to be implemented within the machine control for the on-line optimization of the micromilling process.

Localized canting model for substituted ferrimagnets. I. Singly substituted YIG systems

1970 ◽  
Vol 48 (23) ◽  
pp. 2857-2867 ◽  
Author(s):  
A. Rosencwaig
Keyword(s):  
Experimental Data ◽  
Magnetic Properties ◽  
Statistical Model ◽  
Magnetic Moments ◽  
Exchange Parameter ◽  
New Model ◽  
Model Based ◽  
Curie Temperatures ◽  
Good Agreement

A statistical model based on the concept of localized canting, originally proposed by Geller and coworkers, is developed to account for the magnetic properties of substituted ferrimagnets. This model is used to determine the exchange parameter ratios Jdd/Jdd and Jaa/Jad in YIG systems by evaluating the magnetic moments and Curie temperatures of two classes of singly substituted YIG over the entire substitution range. Good agreement with experimental data is obtained with the physically reasonable exchange parameter ratios of [Formula: see text] and Jaa/Jad *~ 0.07. It is also shown that both the Yafet-Kittel and the Nowik models may be regarded as particular limiting cases of the new model.

A Compact Model for Spherical Rough Contacts

2005 ◽  
Vol 127 (4) ◽  
pp. 884-889 ◽  
Author(s):  
M. Bahrami ◽  
M. M. Yovanovich ◽  
J. R. Culham
Keyword(s):  
Experimental Data ◽  
Pressure Distribution ◽  
Contact Pressure ◽  
Compact Model ◽  
Elastic Contact ◽  
Smooth Surfaces ◽  
New Model ◽  
Maximum Contact ◽  
Good Agreement ◽  
Key Parameter

A new model is developed that considers the effect of roughness on the elastic contact of spherical bodies. A general pressure distribution is proposed that encompasses the contact of rough spheres and yields the Hertzian theory for ideally smooth surfaces. A new parameter, nondimensional maximum contact pressure, is introduced and it is shown that this is the key parameter that controls the contact. The results of the present study are presented in the form of compact relationships. These relationships are compared against the experimental data collected by others and good agreement is observed.

scholarly journals Analytical modelling of the expansion of a solid obstacle interacting with a radiative shock

2018 ◽  
Vol 6 ◽  
Author(s):  
Th. Michel ◽  
E. Falize ◽  
B. Albertazzi ◽  
G. Rigon ◽  
Y. Sakawa ◽  
...  
Keyword(s):  
Experimental Data ◽  
Shock Front ◽  
Spherical Geometry ◽  
Solid Material ◽  
Gas Cell ◽  
Radiative Shock ◽  
New Model ◽  
Shock Temperature ◽  
Laser Facility ◽  
Good Agreement

In this paper, we present a model characterizing the interaction of a radiative shock (RS) with a solid material, as described in a recent paper (Koenig et al., Phys. Plasmas, 24, 082707 (2017)), the new model is then related to recent experiments performed on the GEKKO XII laser facility. The RS generated in a xenon gas cell propagates towards a solid obstacle that is ablated by radiation coming from the shock front and the radiative precursor, mimicking processes occurring in astrophysical phenomena. The model presented here calculates the dynamics of the obstacle expansion, which depends on several parameters, notably the geometry and the temperature of the shock. All parameters required for the model have been obtained from experiments. Good agreement between experimental data and the model is found when spherical geometry is taken into account. As a consequence, this model is a useful and easy tool to infer parameters from experimental data (such as the shock temperature), and also to design future experiments.

scholarly journals Fast and slowly evolving vector solitons in mode-locked fibre lasers

2014 ◽  
Vol 372 (2027) ◽  
pp. 20140006 ◽  
Author(s):  
Sergey V. Sergeyev
Keyword(s):  
Data Storage ◽  
Laser Cavity ◽  
Vector Model ◽  
Fibre Laser ◽  
Linear Birefringence ◽  
Relaxation Dynamics ◽  
New Family ◽  
Erbium Ions ◽  
Erbium Doped ◽  
Long Time

We report on a new vector model of an erbium-doped fibre laser mode locked with carbon nanotubes. This model goes beyond the limitations of the previously used models based on either coupled nonlinear Schrödinger or Ginzburg–Landau equations. Unlike the previous models, it accounts for the vector nature of the interaction between an optical field and an erbium-doped active medium, slow relaxation dynamics of erbium ions, linear birefringence in a fibre, linear and circular birefringence of a laser cavity caused by in-cavity polarization controller and light-induced anisotropy caused by elliptically polarized pump field. Interplay of aforementioned factors changes coherent coupling of two polarization modes at a long time scale and so results in a new family of vector solitons (VSs) with fast and slowly evolving states of polarization. The observed VSs can be of interest in secure communications, trapping and manipulation of atoms and nanoparticles, control of magnetization in data storage devices and many other areas.

Energy Levels and Electromagnetic Transition of 90-94mo Nuclei Using Ibm-1

2020 ◽  
pp. 149-152
Keyword(s):  
Experimental Data ◽  
Transition Probability ◽  
Energy Levels ◽  
Dynamical Symmetry ◽  
Interacting Boson Model ◽  
Excitation Energies ◽  
Electromagnetic Transition ◽  
Boson Model ◽  
Energy States ◽  
Good Agreement

The energy states for the J , b , ɤ bands and electromagnetic transitions B (E2) values for even – even molybdenum 90 – 94 Mo nuclei are calculated in the present work of "the interacting boson model (IBM-1)" . The parameters of the equation of IBM-1 Hamiltonian are determined which yield the best excellent suit the experimental energy states . The positive parity of energy states are obtained by using IBS1. for program for even 90 – 94 Mo isotopes with bosons number 5 , 4 and 5 respectively. The" reduced transition probability B(E2)" of these neuclei are calculated and compared with the experimental data . The ratio of the excitation energies of the 41+ to 21+ states ( R4/2) are also calculated . The calculated and experimental (R4/2) values showed that the 90 – 94 Mo nuclei have the vibrational dynamical symmetry U(5). Good agreement was found from comparison between the calculated energy states and electric quadruple probabilities B(E2) transition of the 90–94Mo isotopes with the experimental data .

Predicting the Effect of Tire Tread Pattern Design on Thick Film Wet Traction

1977 ◽  
Vol 5 (1) ◽  
pp. 6-28 ◽  
Author(s):  
A. L. Browne
Keyword(s):  
Experimental Data ◽  
Network Design ◽  
Thick Film ◽  
Digital Computer ◽  
Analytical Tool ◽  
Design Practice ◽  
Pattern Design ◽  
Performance Results ◽  
Good Agreement

Abstract An analytical tool is presented for the prediction of the effects of changes in tread pattern design on thick film wet traction performance. Results are reported for studies in which the analysis, implemented on a digital computer, was used to determine the effect of different tread geometry features, among these being the number, width, and lateral spacing of longitudinal grooves and the angle of zigzags in longitudinal grooves, on thick film wet traction. These results are shown to be in good agreement with experimental data appearing in the literature and are used to formulate guidelines for tread groove network design practice.

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