Search results for "HAp"
showing 10 items of 2767 documents
High-quality optical pulse train generator based on solitons on finite background
2013
International audience; We report a simple method to exploit the typical properties of solitons on finite background in order to generate high repetition rate and high quality optical pulse trains. We take advantage of the nonlinear evolution of a modulated continuous wave towards localized structures upon a nonzero background wave in anomalous dispersive fiber. After a stage of nonlinear compression, a delay-line interferometer enables the annihilation of the finite background and simultaneously allows the repetition rate doubling of the pulse train.
Tailored waveform generation in mode-locked fiber lasers by in-cavity pulse shaper
2014
International audience; We numerically show the possibility of pulse shaping in a mode-locked fiber laser by inclusion of an amplitude-phase spectral filter into the laser cavity. Various advanced temporal waveforms are generated, including parabolic, flat-top and triangular pulses.
Amplifier similariton fiber laser with nonlinear spectral compression
2012
International audience; We propose a new concept of a fiber laser architecture supporting self-similar pulse evolution in the amplifier and nonlinear spectral pulse compression in the passive fiber. The latter process allows for transform-limited picosecond pulse generation, and improves the laser's power efficiency by preventing strong spectral filtering from being highly dissipative. Aside from laser technology, the proposed scheme opens new possibilities for studying nonlinear dynamical processes. As an example, we demonstrate a clear period-doubling route to chaos in such nonlinear laser system.
Pulse shaping in mode-locked fiber lasers by in-cavity spectral filter
2014
International audience; We numerically show the possibility of pulse shaping in a passively mode-locked fiber laser by inclusion of a spectral filter into the laser cavity. Depending on the amplitude transfer function of the filter, we are able to achieve various regimes of advanced temporal waveform generation, including ones featuring bright and dark parabolic-, flat-top-, triangular- and saw-tooth-profiled pulses. The results demonstrate the strong potential of an in-cavity spectral pulse shaper for controlling the dynamics of mode-locked fiber lasers.
Effects of fourth-order fiber dispersion on ultrashort parabolic optical pulses in the normal dispersion regime
2011
International audience; We propose a new method for the generation of both triangular-shaped optical pulses and flat-top, coherent supercontinuum spectra using the effect of fourth-order dispersion on parabolic pulses in a passive, normally dispersive highly nonlinear fiber. The pulse re-shaping process is described qualitatively and is compared to numerical simulations.
Spazio, forma, materia, contesto. La lezione perpetua di Távora
2022
Fernando Távora è certamente l’iniziatore, il fondatore e l’ideatore di ciò che è riconosciuta come la Scuola di Architettura di Porto. Una Scuola espressione, oggi, di una palingenesi dell’architettura portoghese contemporanea e, forse, senza esagerazione, di un neo-rinascimento architettonico mondiale a cavallo tra il XX e il XXI secolo. Il magister per eccellenza, colui che traccia il primo solco della strada che sarà, in seguito, percorsa dai Discenti - Alvaro Siza Vieira ed Eduardo Souto de Moura - ma con la visione duplice e antitetica di chi sa che la meta si raggiunge volgendo costantemente lo sguardo in avanti e, nel contempo, indietro, al proprio vissuto formativo e al lascito del…
Ultimate field-free molecular alignment by combined adiabatic-impulsive field design
2008
We show that a laser pulse designed as an adiabatic ramp followed by a kick allows one to reach a perfect postpulse molecular alignment, free of saturation. The mechanism is based on an optimized distribution of the energy between a weakly efficient but non saturating adiabatic ramp and an efficient but saturating impulsive field. Unprecedent degrees of alignment are predicted using state-of-the-art pulse shaping techniques and non-destructive field intensities. The scheme can be extended to reach high degrees of orientation of polar molecules using designed half-cycle pulses.
SINGING THE SELF: THE AUTOBIOGRAPHY OF THE FIFTEENTH-CENTURY GERMAN SINGER AND COMPOSER JOHANNES VON SOEST
2010
The German singer, composer and writer Johannes von Soest (1448–1506), also referred to as Steinwart or Steinwert, is the author of a vernacular autobiography in verse. One of the very few such documents written by a musician, it gives a highly personal insight into his career, which extended from his training as a chorister in Soest to the ducal chapel in Cleves and afterwards to Bruges (in the company of two unnamed English musicians), Aardenburg (Overijssel), Maastricht, possibly Cologne, Kassel and finally Heidelberg, where he was appointed as Kapellmeister. He subsequently decided to become a physician. The article includes a complete transcription of the text, whose original was destr…
Fra testo e musica: l’opposizione 'gai' / 'greu' nella canzone dei trovatori
2021
La questione dei rapporti fra testo e musica nei trovatori è stata affrontata secondo prospettive diverse, in cui raramente si verifica una reale convergenza fra i presupposti epistemici e metodologici della filologia romanza e della musicologia medievale. In questo intervento si cercherà di valutare se e fino a che punto l’opposizione fra melodie ‘gaie’ e ‘gravi’ che emerge dai testi poetici sia riferibile anche ad alcune delle melodie trasmesse, configurando in ultima analisi una caratterizzazione ‘etica’ del testo musicale in relazione a quello verbale all’interno del genere canzone. The question of the relationship between text and music in the Troubadour corpus has been approached from…
Financial Behaviour Under Economic Strain in Different Age Groups: Predictors and Change Across 20 Years
2021
AbstractThe present study examined the multiple micro- and macro-level factors that affect individuals’ financial behaviour under economic strain. The following sociodemographic and economic factors that predict financial behaviour were analysed: age group, year of data gathering, and attitudes towards consumption (economical, deprived, and hedonistic). Subjective financial situations and demographic characteristics were controlled for. Finnish time series data that consisted of five cross-sectional nationally representative surveys were used (n = 10 043). The analyses revealed four types of financial behaviour: cutting expenses, borrowing, increasing income, and gambling. Young adults aged…