Person: Cabrera Granado, Eduardo
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First Name
Eduardo
Last Name
Cabrera Granado
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Óptica y Optometría
Department
Óptica
Area
Optica
Identifiers
21 results
Search Results
Now showing 1 - 10 of 21
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 Control of upconversion luminescence by gold nanoparticle size: from quenching to enhancement(Nanoscale, 2019) Méndez González, Diego; Melle Hernández, Sonia; Gómez Calderón, Óscar; Laurenti, Marco; Cabrera Granado, Eduardo; Egatz-Gómez, Ana; López Cabarcos, Enrique; Rubio Retama, Jorge; Díaz García, ElenaMetallic nanostructures have the potential to modify the anti-Stokes emission of upconverting nanoparticles (UCNPs) by coupling their plasmon resonance with either the excitation or the emission wavelength of the UCNPs. In this regard gold nanoparticles (AuNPs) have often been used in sensors for UCNP luminescence quenching or enhancement, although systematic studies are still needed in order to design optimal UCNP–AuNP based biosensors. Amidst mixed experimental evidence of quenching or enhancement, two key factors arise: the nanoparticle distance and nanoparticle size. In this work, we synthesize AuNPs of different sizes to assess their influence on the luminescence of UCNPs. We find that strong luminescence quenching due to resonance energy transfer is preferentially achieved for small AuNPs, peaking at an optimal size. A further increase in the AuNP size is accompanied by a reduction of luminescence quenching due to an incipient plasmonic enhancement effect. This enhancement counterbalances the luminescence quenching effect at the biggest tested AuNP size. The experimental findings are theoretically validated by studying the decay rate of the UCNP emitters near a gold nanoparticle using both a classical phenomenological model and the finite-difference time-domain method. Results from this study establish general guidelines to consider when designing sensors based on UCNPs–AuNPs as donor–quencher pairs, and suggest the potential of plasmon-induced luminescence enhancement as a sensing strategy.Item FRET distance dependence from upconverting nanoparticles to quantum dots(Journal of physical chemistry C, 2018) Melle Hernández, Sonia; Gómez Calderón, Óscar; Laurenti, Marco; Méndez González, Diego; Egatz-Gómez, Ana; López Cabarcos, Enrique; Cabrera Granado, Eduardo; Díaz García, Elena; Rubio Retama, JorgeFörster resonant energy transfer (FRET) with upconverting nanoparticles (UCNPs) as donors and quantum dots (QDs) as acceptors has been regarded as a promising tool for biosensing applications. In this work, we use time-resolved fluorescence spectroscopy to analyze the UCNP-to-QD FRET and we focus on the most relevant parameter of the FRET phenomenon, UCNP-QD distance. This distance is controlled by a nanometric silica shell around the UCNP surface. We theoretically reproduce the experimental results applying FRET theory to the distribution of emitting erbium ions in the UCNP. This simple model allows us to estimate the contribution of every erbium ion to the final FRET response and to explore different strategies to improve FRET efficiency.Item Plasmon-enhanced terahertz emission in self-assembled quantum dots by femtosecond pulses(Journal of Applied Physics, 2014) Carreño Sánchez, Fernando; Antón Revilla, Miguel Ángel; Melle Hernández, Sonia; Gómez Calderón, Óscar; Cabrera Granado, Eduardo; Cox, Joel; Singh, Mahi R.; Egatz-Gómez, AnaA scheme for terahertz (THz) generation from intraband transition in a self-assembled quantum dot (QD) molecule coupled to a metallic nanoparticle (MNP) is analyzed. The QD structure is described as a three-level atom-like system using the density matrix formalism. The MNP with spherical geometry is considered in the quasistatic approximation. A femtosecond laser pulse creates a coherent superposition of two subbands in the quantum dots and produces localized surface plasmons in the nanoparticle which act back upon the QD molecule via dipole-dipole interaction. As a result, coherent THz radiation with a frequency corresponding to the interlevel spacing can be obtained, which is strongly modified by the presence of the MNP. The peak value of the terahertz signal is analyzed as a function of nanoparticle's size, the MNP to QD distance, and the area of the applied laser field. In addition, we theoretically demonstrate that the terahertz pulse generation can be effectively controlled by making use of a train of femtosecond laser pulses. We show that by a proper choice of the parameters characterizing the pulse train a huge enhancement of the terahertz signal is obtained.Item Propagation-induced transition from slow to fast light in highly doped erbium fibers(Physical review A, 2008) Gómez Calderón, Óscar; Melle Hernández, Sonia; Antón Revilla, Miguel Ángel; Carreño Sánchez, Fernando; Arrieta Yáñez, Francisco; Cabrera Granado, EduardoWe analyze the propagation regime of an amplitude-modulated 1536 nm signal when traveling along a highly doped erbium fiber pumped at 977 nm as a function of the fiber length. A propagation-induced transition from superluminal to subluminal propagation takes place along the fiber length which allows a change in regime solely based upon increasing the signal modulation frequency. This peculiar behavior is due to the interplay between pump absorption and pump-power broadening of the spectral hole induced by coherent population oscillations. The effect of ion density on this frequency-dependent regime change has been investigated.Item Radiation emission from an asymmetric quantum dot coupled to a plasmonic nanostructure(Journal of Optics, 2016) Antón Revilla, Miguel Ángel; Carreño Sánchez, Fernando; Gómez Calderón, Óscar; Melle Hernández, Sonia; Cabrera Granado, EduardoWe propose a scheme for controlling the absorption and RFS of a quantum dot (QD) with broken inversion symmetry interacting with a plasmonic nanostructure. The QD is described as a two-level atom-like system with a permanent dipole moment in the excited state. A linearly polarized laser field drives the optical transition of the QD and produces localized surface plasmons in the MNP. The influence of plasmonic effects between the nanoparticle and the dot is analyzed using the Green tensor method. We found terahertz (THz) emission in the resonance fluorescence spectrum when the laser frequency lies above the transition frequency. The position and strength of the THz peaks is controlled by means of the dot-nanoparticle separation. The quantum nature of the emitted THz photons is analyzed by evaluating the second-order fluorescence intensity correlation function. We found a periodic alternation of photon bunching and anti-bunching with a period that depends on the polarization of the driving field.Item Phase shift of amplitude-modulated optical signals in graphene oxide water dispersions due to thermal lens focal length oscillation(Journal of the Optical Society of America B, 2014) Melle Hernández, Sonia; Gómez Calderón, Óscar; Egatz-Gómez, Ana; Cabrera Granado, Eduardo; Carreño Sánchez, Fernando; Salavagione, H. J.; Antón Revilla, Miguel ÁngelWe analyze the phase shift induced in an amplitude-modulated laser beam propagating through a water dispersion of graphene oxide sheets in a fiber-to-fiber U-bench. This phase shift arises from the thermally induced nonlinear refraction in the sample. The system exhibits strong optical limiting performance for weak continuous-wave signals. A theoretical model including beam propagation and thermal lens focal length oscillation reproduces the experimental findings.- Project number: 200
Item Desarrollo de herramientas interactivas con acceso remoto para el aprendizaje de óptica biomédica(2015) Cabrera Granado, Eduardo; Gómez Calderón, Óscar; Melle Hernández, Sonia; Antón Revilla, Miguel Ángel; Carreño Sánchez, Fernando; Díaz García, Elena; López Alonso, José Manuel; Arrieta Yañez, FranciscoNuevos documentos de trabajo y consulta basados en IPython Notebook han sido desarrollados con el fin de ofrecer nuevas herramientas para el aprendizaje de la asignatura de Óptica Biomédica de la Facultad de Óptica y Optometría. Este tipo de documentos permiten una mayor libertad al estudiante para explorar distintos temas de Óptica Biomédica facilitando su acceso remoto sin la necesidad de instalar software en su ordenador personal. - Project number: 101
Item Desarrollo de experiencias prácticas para el aprendizaje activo en Óptica(2023) Melle Hernández, Sonia; Gómez Calderón, Óscar; Cabrera Granado, Eduardo; Casillas Rubio, Alejandro; Encinas Sanz, Fernando; Melle Hernández, SoniaEn este proyecto se han desarrollado una serie de experiencias prácticas sencillas que permiten un acercamiento de los alumnos que cursan estudios de Óptica a fenómenos relacionados con la luz fomentando un aprendizaje activo. Las experiencias propuestos no requieren de materiales especializados ni de montajes complejos de laboratorio. Se ha elaborado un manual interactivo en formato Jupyter Notebook incluyendo una descripción detallada de cada experiencia práctica acompañada de vídeos explicativos. Este enfoque fomenta la participación proactiva de los alumnos, permitiéndoles no solo presenciar los fenómenos ópticos, sino también reflexionar sobre ellos, formular hipótesis, plantear preguntas y analizar los resultados obtenidos. - Project number: 134
Item Documentos interactivos libres para una metodología docente de “aula invertida”(2017) Cabrera Granado, Eduardo; Díaz García, Elena; Melle Hernández, Sonia; Ortega Moreno, Sergio; Gómez Calderón, Óscar
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