Simple and efficient method of lines based algorithm for modelling of erbium doped Q-switched fluoride fiber lasers

An improved algorithm based on the method of lines for modelling of Q-switched fluoride glass based erbium doped fiber lasers is presented. The algorithm uses finite difference method to reduce partial differential equations to a set of ordinary differential equations. Unlike the method of characteristics the ratio of the temporal and spatial step is not fixed. Thus computationally efficient algorithms with an adaptive step control for the solution of a set of ordinary differential equations can be directly applied. The performance of the improved algorithm against the standard one is compared. The results obtained show that the improved algorithm is significantly more computationally efficient

The German electronic order for payment procedure

Bartosz Sujecki describes the procedure to make a claim for money that is owed and not paid, including a brief overview of the history of the procedure

An Efficient Algorithm for Steady State Analysis of Fibre Lasers Operating under Cascade Pumping Scheme

We derive an efficient algorithm for the steady state analysis of fibre lasers operating under cascade pumping scheme by combining the shooting method with the Newton-Raphson method. We compare the proposed algorithm with the two standard algorithms that have been used so far in the available literature: the relaxation method and the coupled solution method. The results obtained show that the proposed shooting method based algorithm achieves much faster convergence rate at the expense of a moderate increase in the calculation time.  It is found that a further improvement in the computational efficiency can be achieved by using few iterations of the relaxation method to calculate the initial guess for the proposed shooting method based algorithm

Fundamentele herbezinning op de betalingsbevelprocedure

In dit artikel worden de voorstellen van de Commissie Fundamentele Herbezin-ning op het burgerlijk procesrecht met betrekking tot de invoering van een betalingsbevel-procedure bekeken en vergeleken met de eind 2006 vastgestelde verordening tot invoering van een Europese betalingsbevelprocedure. Geconcludeerd wordt dat het wenselijk is een nationale betalingsbevelprocedure in te voeren, waarbij de Europese betalingsbevelprocedu-re met enkele aanpassingen model kan staa

De Europese betalingsbevelprocedure

Dit artikel bevat een kritische analyse van de (voorgestelde) verordening voor een Europese betalingsbevelprocedure (EBB-Vo). Aandacht wordt besteed aan de betalingsbevelprocedure in het algemeen en onder het nationale recht, de achtergrond van het Europees betalingsbevel, de inhoud en de implementatie van de verordening. Ons standpunt over de EBB-Vo is gematigd positief. Als mogelijke knelpunten worden gesignaleerd de onnodige uitsluiting van niet-contractuele vorderingen in art. 2 lid 2, de bevoegdheidsregeling van art. 6, de tweeslachtige regeling van de bewijsregeling en toetsing in art. 7 en 8, en de regeling van de heroverweging in art. 20. --- Verordening nr. 1896/2006, vastgesteld op 12 december 2006 Abstract: [The European Order for Payment Procedure. A critical analysis] In this article the European Order for Payment Procedural is thoroughly reviewed. Attention is paid to the or-der for payment procedure in general, background of the European Order for Payment, contents of the regulation and implementation. In general we support this regulation, but we identify some weak points. These are the exclusion of non contractual obligations in Art. 2, para 2 which is unnecessarily complicating, the jurisdiction rule laid down in Art. 6, the am-biguous rules regarding evidence and examination of the application laid down in Art. 7 and 8, and the rules regarding review in Art. 20. --- Regulation no. 1896/2006, established on 12 December 200

Numerical Analysis of Q-Switched Erbium Ion Doped Fluoride Glass Fiber Laser Operation Including Spontaneous Emission

Partial differential equations are solved to perform a spatiotemporal analysis of Q-switched operation of a fluoride fiber laser doped with erbium ions. A method of lines is applied in order to reduce the partial differential equations to a set of ordinary differential equations. The latter set is then solved using an algorithm designed for a solution of stiff equation problems. A spontaneous emission term is added to equations that model the dynamics of the photon population within the laser cavity for the infrared signal wave. The results show that, without an inclusion of the spontaneous emission term, the correct behavior of the photon population and energy level populations cannot be reproduced

Narrow-line coherently combined tapered laser diodes in a Talbot external cavity with a volume Bragg grating

We present the phase locking of an array of index-guided tapered laser diodes. An external cavity based on the self-imaging Talbot effect has been built. A volume Bragg grating is used as the output coupler to stabilize and narrow the spectrum at 976 nm. A power of 1.7 W is achieved in the in-phase single main lobe mode with a high visibility. We have checked that each emitter is locked to the Bragg wavelength with a 100 pm spectrum linewidth. The experimental results compare well with numerical simulations performed with two-dimensional wide-angle finite difference beam propagation method

Socjologia wiedzy jako perspektywa badawcza w analizie interpretacji wzorca programowego

Transformation of the political system in Poland has created a new friendly environment for the research on the history of social movements, including socialistic program, formulated basing on Marxism. The lack of any ideological pressure and censorship restrictions formed particularly advantageous circumstances for the researchers interested in the history of the socialistic concept. Today one can consider whether the opportunity which appeared by vanishing the ideological corset has been used properly. In the 1990s, the former approach, usually coming down to treating Marxism as religious dogma, was replaced by negation mostly resulting in the elimination of the issue itself. You could observe a tendency to avoid the research on the history of socialistic concept, so necessary after decades of barriers, resulting in passing over in silence or misrepresentations. The foregoing considerations show vital stages of the process of forming program interpretations created basing on Marxism. However, the presented here schematic depiction may also be useful for demonstrating the process of formulating the program constructed as one of a few variants of any doctrine, i.e. a pattern. The choice of Marxism as a program pattern is only a consequence of referring to an instance of the hagiography of the Polish socialistic movement and is strictly related to my interests concerning the history of the Polish socialistic concept. I regard the suggestions presented here as my voice in the discussion lasting since 1990 on the use of research abilities being a result of the political system transformation in Polan

Modelling chaos in asymmetric optical fibres

A ray dynamical approach is developed for the study of large-core asymmetric step index fibres (SIF), especially those made from chalcogenide glasses (ChGs) which can exhibit very high refractive index, large numerical aperture, and which are transparent at mid-infrared wavelengths. The model allows for deformations of the SIF away from concentric circular structures, and for the light rays captured by the fibre to behave chaotically within the asymmetric boundaries of the fibre. Chaotic and periodic rays can be classified by the Poincaré surface of sections (SOSs). In the model, the ray dynamics in the SIF are approximated by dividing the SOSs into pixels; the construction of a transfer matrix stores all the mapping probabilities. The light intensity distribution in the SOSs is efficiently propagated using the constructed transfer matrix, providing a viable alternative to propagating all the rays in the SIF by brute force ray tracing. The model enables the rapid calculation of the power accumulated in the fibre core following an arbitrary excitation