Person: Weigand Talavera, Rosa María
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First Name
Rosa María
Last Name
Weigand Talavera
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Físicas
Department
Óptica
Area
Optica
Identifiers
18 results
Search Results
Now showing 1 - 10 of 18
Item On the generality of measuring ultrabroad-band ultrashort laser pulses with the d-scan technique using ensembles of dielectric nano- and microparticles(Optics and Laser Technology, 2024) Pérez Benito, Óscar; Cabrera Granado, Eduardo; García Martín, Susana; García González, Ester; Weigand Talavera, Rosa MaríaWe demonstrate that temporal characterization of ultrabroadband laser pulses (∼ 7 fs) through the d-scan technique can be implemented using ensembles of SHG micro and/or nanocrystals independently of their crystal size and/or composition. The experimental results have been supported by numerical simulations based on the Finite-Difference-Time-Domain (FDTD) algorithm. Both, experiment and simulations show that, in spite of the low optical quality of the samples and the unavoidable appearance of incoherent light, the technique is robust and allows to measure ultrashort laser pulses using clusters of randomly distributed and piled-up polar micro- and nanocrystals.Item Fundamentals of Highly Non-Degenerate Cascaded Four-Wave Mixing(Applied Sciences, 2015) Weigand Talavera, Rosa María; Crespo, HelderBy crossing two intense ultrashort laser pulses with different colors in a transparent medium, like a simple piece of glass, a fan of multicolored broadband light pulses can be simultaneously generated. These newly generated pulses are emitted in several well-defined directions and can cover a broad spectral range, from the infrared to the ultraviolet and beyond. This beautiful phenomenon, first observed and described 15 years ago, is due to highly-nondegenerate cascaded four-wave mixing (cascaded FWM, or CFWM). Here, we present a review of our work on the generation and measurement of multicolored light pulses based on third-order nonlinearities in transparent solids, from the discovery and first demonstration of highly-nondegenerate CFWM, to the coherent synthesis of single-cycle pulses by superposition of the multicolored light pulses produced by CFWM. We will also present the development and main results of a dedicated 2.5-D nonlinear propagation model, i.e., with propagation occurring along a two-dimensional plane while assuming cylindrically symmetric pump beam profiles, capable of adequately describing noncollinear FWM and CFWM processes. A new method for the generation of femtosecond pulses in the deep-ultraviolet (DUV) based on FWM and CFWM will also be described. These experimental and theoretical results show that highly-nondegenerate third-order nonlinear optical processes are formally well understood and provide broader bandwidths than other nonlinear optical processes for the generation of ultrashort light pulses with wavelengths extending from the near-infrared to the deep-ultraviolet, which have many applications in science and technology.Item Estudio espectroscópico y efecto láser en SO(2)-análogos de Pteridinas y Piridopirimidinas(2002) Weigand Talavera, Rosa María; Guerra Pérez, José Manuel; Dávila Muro, JorgeEl objeto de estudio de esta tesis ha sido, por un lado, la caracterización espectroscópica de algunos derivados de dos familias de compuestos: 2,2-dioxidos de aminopirido (2,3-c) -1,2,6-tiadiazinas y 2,2-dioxidos de pirazino(2,3-c)-1,2,6-tiadiazinas en dimetilsulfoxido y acetonitrilo, con objeto de ver su aplicación como láseres de colorante. Estos compuestos presentan comportamiento acido-base en estos disolventes y las diferentes especies han sido caracterizadas a través de espectros de absorción y fluorescencia, eficiencias cuánticas y tiempos de vida. Asimismo se han caracterizado los procesos acido-base que existen entre ellas a través de los pka y pka* o constantes cinéticas. Por otro lado se ha desarrollado un modelo que describe el efecto láser en sistemas acido-base, cuya resolucion numérica nos ha permitido dar una casuística de los regímenes espectro- temporales de funcionamiento láser presente en estos sistemas. Por ultimo se ha estudiado experimentalmente el efecto láser en las especies de los diversos compuestos, analizando rango espectral, eficiencia y comportamiento temporal de la emisión láser y se han reproducido las medidas experimentales con el modelo propuesto.- Project number: 240
Item Aplicabilidad del software de Diferencias Finitas en el Dominio del Tiempo (FDTD) al aprendizaje en Fotónica(2017) Weigand Talavera, Rosa María; Calvo Padilla, María Luisa; Gonzalo Fonrodona, Isabel; Villafranca Velasco, AitorSe generaran topografías FDTD en sistemas fotónicos para ejemplificación en clase por parte del profesor, realización de trabajos en grupo, realización de prácticas de laboratorio, autoaprendizaje del alumno y Trabajos Fin de Grado y Máster. Item Dispersion-scan measurements of few-cycle pulses compressed with the multiplate continuum process(2017 Conference On Lasers and Electro-Optics Europe & European Quantum Electronics Conference (Cleo/Europe-Eqec), 2017) Canhota, Miguel; Weigand Talavera, Rosa María; Crespo, Helder M.- Project number: PIMCD83/23-24
Item Prácticas en óptica avanzada: desarrollo y método de evaluación(2024) Alieva Krasheninnikova, Tatiana; Martínez Matos, Óscar; Weigand Talavera, Rosa María; Rodrigo Martín Romo, José Augusto; Rosich Velarde, Diego; Pérez Benito, Óscar; Franco Rodríguez, Enar; Diez Garrote FranciscoEl proyecto se enfoca en la mejora de la calidad de la enseñanza práctica en la asignatura Coherencia Óptica y Láser del cuarto curso del Grado en Física y en la asignatura obligatoria Instrumentación Biomédica del Máster en Física Biomédica. Para ello se han desarrollado prácticas avanzadas en el área de Óptica, modernizado los contenidos de prácticas ya existentes y actualizado los métodos de evaluación de los resultados de aprendizaje del estudiante. Item Full temporal characterization of ultrabroadband few-cycle laser pulses using atomically thin WS_2(ACS Photonics, 2023) Pérez Benito, Óscar; Hernández Rueda, Francisco Javier; Martínez Maestro, Laura; Noordam, Marc L.; Kuipers, L.; Weigand Talavera, Rosa MaríaNowadays, the accurateand full temporal characterization of ultrabroadbandfew-cycle laser pulses withpulse durations below 7 fs is of great importance in fields of sciencethat investigate ultrafast dynamic processes. There are several indirectmethods that use nonlinear optical signals to retrieve the complexelectric field of femtosecond lasers. However, the precise characterizationof few-cycle femtosecond laser sources with an ultrabroadband spectrumpresents additional difficulties, such as reabsorption of nonlinearsignals, partial phase matching, and spatiotemporal mismatches. Inthis work, we combine the dispersion scan (d-scan) method with atomicallythin WS2 flakes to overcome these difficulties and fullycharacterize ultrabroadband laser pulses with a pulse duration of6.9 fs and a spectrum that ranges from 650 to 1050 nm. Two-dimensionalWS(2) acts as a remarkably efficient nonlinear medium thatoffers a broad transparency range and allows for achieving relaxedphase-matching conditions due to its atomic thickness. Using mono-and trilayers of WS2, we acquire d-scan traces by measuringthe second-harmonic generation (SHG) signal, originated via laser-WS2 interaction, as a function of optical dispersion (i.e., glassthickness) and wavelength. Our retrieval algorithm extracts a pulseduration at full-width half-maximum of 6.9 fs and the same spectralphase function irrespective of the number of layers. We benchmarkand validate our results obtained using WS2 by comparingthem with those obtained using a 10-mu m-thick BBO crystal. Ourfindings show that atomically thin media can be an interesting alternativeto micrometer-thick bulk crystals to characterize ultrabroadband femtosecondlaser pulses using SHG-d-scan with an error below 100 as (attoseconds).Item Powerful algebraic model to design Q-switched lasers using saturable absorbers(Optics and laser technology, 2023) Pérez Alonso, Vanesa; Weigand Talavera, Rosa María; Sánchez Balmaseda, Margarita María; Guerra Pérez, José ManuelUsing the rate equations and their stability analysis, an algebraic model has been developed to predict the values of characteristic magnitudes of the output of a laser operating in passive Q-switched regime, such as peak power, temporal pulse width, pulse energy and pulse period. The results are compared with the numerical integrations of the equations, and an excellent agreement in a vast range of values of the laser parameters (gain, saturable absorption, linear losses, cavity round-trip and saturation energies and lifetimes of laser medium and absorber) has been obtained. The model is very useful to design this type of lasers in an agile way, without the need of integration of the corresponding rate equations.Item Líneas de investigación del Grupo UCM de Física del Láser, Óptica Cuántica y Óptica No Lineal(Óptica Pura y Aplicada, 2011) Antón Revilla, Miguel Ángel; Arrieta Yáñez, Francisco; Cabrera Granado, Eduardo; Carreño Sánchez, Fernando; Ezquerro Rodríguez, José Miguel; Gómez Calderón, Óscar; Gonzalo Fonrodona, Isabel; Guerra Pérez, José Manuel; Melle Hernández, Sonia; Soler Rus, Miguel Odín; Sánchez Balmaseda, Margarita María; Weigand Talavera, Rosa MaríaEn este trabajo presentamos las líneas de investigación del Grupo de Física del Láser, Óptica Cuántica y Óptica No Lineal de la UCM. La investigación comprende trabajos experimentales y teóricos en el desarrollo de prototipos de láser, análisis de inestabilidades espacio-temporales en láseres de gran apertura, el estudio de propagación de radiación en régimen de luz lenta y de pulsos ultracortos en medios resonantes y no resonantes, la generación de radiación por procesos no lineales y el estudio de memorias ópticas por eco fotónico.Item On the Q-switched operation of Titanium: sapphire lasers using a graphene-based saturable absorber mirror(Optics and laser technology, 2015) Weigand Talavera, Rosa María; Pinto, T.; Crespo, H. M.; Guerra, J. M.We numerically demonstrate Q-switched operation of Titanium:Sapphire lasers using mono and multilayer graphene, deposited on a totally reflecting end mirror as a saturable absorber. Output energies, pulse duration and repetition frequencies of the Q-switched pulse trains are given as a function of the pump intensity for different number of graphene layers and cavity lengths. For the geometries studied, pulses from 17 to 491 ns can be achieved, with energies ranging from 11 to 74 μJ and repetition rates from 0.06 to 2.5 MHz. These results can be useful for designing and building laser cavities for Q-switched and mode-locked operation in laser media with short lifetimes as Titanium:Sapphire.