Now showing items 525-544 of 572

    • Tailoring light polarization in vertical cavity surface emitting lasers by isotropic optical feedback from an extremely short external cavity 

      Arizaleta Arteaga, Mikel Upna; López-Amo Sáinz, Manuel Upna; Thienpont, Hugo; Panajotov, Krassimir (AIP Publishing, 2006)   Artículo / Artikulua  OpenAccess
      The authors experimentally show that isotropic optical feedback from an extremely short external cavity can induce switching between the two fundamental transverse modes with orthogonal linear polarization of otherwise ...
    • Technical specifications and quality control procedures for reducing the uncertainty in PV installations: results of the FP7 project PVCROPS 

      Martínez Moreno, Francisco; Lorenzo Pigueiras, Eduardo; Narvarte Fernández, Luis; Moretón Villagra, Rodrigo; Tyutyundzhiev, Nicolay; Parra Laita, Íñigo de la Upna (EU PVSEC, 2015)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      PVCROPS (PhotoVoltaic Cost r€duction, Reliability, Operational performance, Prediction and Simulation) is a project within the European Framework Programme 7 whose objectives are: improving the performance, reliability ...
    • Temperature sensor based on a hybrid ITOsilica resonant cavity 

      Socorro Leránoz, Abián Bentor Upna; Soltani, Soheil; Del Villar, Ignacio Upna; Corres Sanz, Jesús María Upna; Armani, Andrea M. (Optical Society of America, 2015)   Artículo / Artikulua  OpenAccess
      Integrated optical devices comprised of multiple material systems are able to achieve unique performance characteristics, enabling applications in sensing and in telecommunications. Due to ease of fabrication, the majority ...
    • Temperature sensor using a multiwavelength erbium-doped fiber ring laser 

      Díaz Lucas, Silvia Upna; San Fabián García, Noé Upna; Socorro Leránoz, Abián Bentor Upna; Matías Maestro, Ignacio Upna (Hindawi, 2017)   Artículo / Artikulua  OpenAccess
      A novel temperature sensor is presented based on a multiwavelength erbium-doped fiber ring laser.The laser is comprised of fiber Bragg grating reflectors as the oscillation wavelength selecting filters.The performance of ...
    • Terahertz carpet cloak based on a ring resonator metasurface 

      Orazbayev, Bakhtiyar Upna; Mohammadi Estakhri, Nasim; Beruete Díaz, Miguel Upna; Alù, Andrea (American Physical Society, 2015)   Artículo / Artikulua  OpenAccess
      In this work we present the concept and design of an ultrathin (λ/22) terahertz (THz) unidirectional carpet cloak based on the local phase compensation approach enabled by gradient metasurfaces. A triangular surface bump ...
    • Terahertz epsilon-near-zero graded-index lens 

      Torres Landívar, Víctor Upna; Pacheco-Peña, Víctor Upna; Rodríguez Ulibarri, Pablo Upna; Navarro Cía, Miguel Upna; Beruete Díaz, Miguel Upna; Sorolla Ayza, Mario Upna; Engheta, Nader (Optical Society of America, 2013)   Artículo / Artikulua  OpenAccess
      An epsilon-near-zero graded-index converging lens with planar faces is proposed and analyzed. Each perfectly-electric conducting (PEC) waveguide comprising the lens operates slightly above its cut-off frequency and has ...
    • Terahertz time domain spectroscopy allows contactless monitoring of grapevine water status 

      Santesteban García, Gonzaga Upna; Palacios Horcajada, Inés Upna; Miranda Jiménez, Carlos Upna; Iriarte Galarregui, Juan Carlos Upna; Royo Díaz, José Bernardo Upna; Gonzalo García, Ramón Upna (Frontiers Media, 2015)   Artículo / Artikulua  OpenAccess
      Agriculture is the sector with the greatest water consumption, since food production is frequently based on crop irrigation. Proper irrigation management requires reliable information on plant water status, but all the ...
    • Terahertz wave transmission in flexible polystyrene-lined hollow metallic waveguides for the 2.5-5 THz band 

      Navarro Cía, Miguel Upna; Vitiello, Miriam S.; Bledt, Carlos M.; Melzer, Jeffrey E.; Harrington, James A.; Mitrofanov, Oleg (Optical Society of America, 2013)   Artículo / Artikulua  OpenAccess
      A low-loss and low-dispersive optical-fiber-like hybrid HE11 mode is developed within a wide band in metallic hollow waveguides if their inner walls are coated with a thin dielectric layer. We investigate terahertz (THz) ...
    • Terajets produced by dielectric cuboids 

      Pacheco-Peña, Víctor Upna; Beruete Díaz, Miguel Upna; Minin, Igor V.; Minin, Oleg V. (AIP Publishing, 2014)   Artículo / Artikulua  OpenAccess
      The capability of generating terajets using three-dimensional (3D) dielectric cuboids working at terahertz (THZ) frequencies (as analogues of nanojets in the infrared band) is introduced and studied numerically. The focusing ...
    • Theory and model of the hyperacuity in the human eye 

      Domínguez López de Lacalle, Oier Upna (2015)   Tesis doctoral / Doktoretza tesia  OpenAccess
      The hyperacuity of the human eye may be defined as its known capacity to see small details far away from the limitations set by the number and size of the detectors it has. Basically, the problem consists in the fact ...
    • Title enhancement of the sensitivity of a volatile organic compounds MOF-sensor by means of its structure 

      López Torres, Diego Upna; López Aldaba, Aitor Upna; Elosúa Aguado, César Upna; Auguste, Jean-Louis; Jamier, Raphael; Roy, Philippe; López-Amo Sáinz, Manuel Upna; Arregui San Martín, Francisco Javier Upna (MDPI, 2017)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      In this paper, we experimentally compare several core structures of Microstructured Optical Fibers (MOFs) for low-finesse Fabry-Pérot (FP) sensors. These sensors are designed for Volatile Organic Compounds (VOCs) measurements. ...
    • Tools for the high penetration of PV systems in the EU electrical networks: results of PVCROPS Project 

      Narvarte Fernández, Luis; Marroyo Palomo, Luis Upna; Collares Pereira, Manuel; Tyutyundzhiev, Nicolay; Conlon, Michael; Bouzzan, N.; Guelbenzu Michelena, Eugenio; González, R.; Desportes, Adrien; Simmonds, Gary; Wilkin, Benjamin (EU PVSEC, 2015)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      The Solar Energy Industrial Initiative established the objective of integrating PV into the grid to provide up to 12% of the EU electricity demand. The FP7 project PVCROPS has developed solutions to allow the high penetration ...
    • Towards a traceability system based on RFID technology to check the content of pallets within electronic devices supply chain 

      Angulo Martínez, Ignacio; Perallos Ruiz, Asier; Azpilicueta Fernández de las Heras, Leyre Upna; Falcone Lanas, Francisco Javier Upna; Hernández Jayo, Unai; Moreno, Asier; García Zuazola, Ignacio Julio (Hindawi, 2013)   Artículo / Artikulua  OpenAccess
      In the last few years there has been a growing interest in smart solutions capable of dealing with the traceability of products and materials to improve logistical processes. Most of the existing solutions have been ...
    • Transición coaxial a guía doble ridge cargada 

      Cantora Álvarez, Pablo; Río Bocio, Carlos del Upna; Teniente Vallinas, Jorge Upna (2005)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      In this paper a new method to design a transition from coaxial waveguide to a loaded double ridge waveguide is proposed. This method allows the use of the large frequency bandwidth ridge waveguides present. In the ...
    • Transmission spectra changes produced by decreasing compactness of opal-like structures 

      Andueza Unanua, Ángel María Upna; Echeverría, R.; Morales Zimmermann, Paola Andrea Upna; Sevilla Moróder, Joaquín Upna (AIP Publishing, 2009)   Artículo / Artikulua  OpenAccess
      Artificial opal-like structures based on spheres and colloidal particles have been fabricated in a controlled way, presenting optical band-gap properties in the optical frequency range. Nonclose packed artificial opals ...
    • Tunable beam steering enabled by graphene metamaterials 

      Orazbayev, Bakhtiyar Upna; Beruete Díaz, Miguel Upna; Khromova, Irina Upna (Optical Society of America, 2016)   Artículo / Artikulua  OpenAccess
      We demonstrate tunable mid-infrared (MIR) beam steering devices based on multilayer graphene-dielectric metamaterials. The effective refractive index of such metamaterials can be manipulated by changing the chemical potential ...
    • Tunable electro-optic wavelength filter based on lossy-guided mode resonances 

      Corres Sanz, Jesús María Upna; Ascorbe Muruzabal, Joaquín Upna; Arregui San Martín, Francisco Javier Upna; Matías Maestro, Ignacio Upna (Optical Society of America, 2013)   Artículo / Artikulua  OpenAccess
      In this work an optical fiber tunable filter based on lossy guided-mode resonances (LGMR) is proposed. It consists of a multilayer structure deposited onto the surface of a plastic cladding removed multimode fiber. The ...
    • Tunable SESAM-based mode-locked soliton fiber laser in linear cavity by axial-strain applied to a FBG 

      Aporta, I.; Leandro González, Daniel Upna; Quintela, M. A.; Pérez Herrera, Rosa Ana Upna; López-Amo Sáinz, Manuel Upna; López Higuera, José Miguel (IEEE, 2017)   Artículo / Artikulua  OpenAccess
      A self-started stable tunable mode-locked (ML) soliton fiber laser in a linear cavity structure composed by commercial passive elements is presented in this paper. It is based on the combination of an Erbium doped fiber ...
    • Two methods for nonparametric spectrum peak discrimination 

      Zivanovic, Miroslav Upna; Carlosena García, Alfonso Upna (2002)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      The conventional DFT-oriented nonparametric interpolation methods, based on time windowing and the DTFT envelope curve resampling (zero padding, Chirp-z [1], frequency scale distortion [2], etc.), can improve the spectrum ...
    • Ubiquitous connected train based on train-to-ground and intra-wagon communications capable of providing on trip customized digital services for passengers 

      Salaberria, Itziar; Perallos Ruiz, Asier; Azpilicueta Fernández de las Heras, Leyre Upna; Falcone Lanas, Francisco Javier Upna; Carballedo, Roberto; Angulo Martínez, Ignacio; Elejoste Larrucea, Pilar; Bahillo, Alfonso; Astrain Escola, José Javier Upna; Villadangos Alonso, Jesús Upna (MDPI, 2014)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      During the last years, the application of different wireless technologies has been explored in order to enable Internet connectivity from vehicles. In addition, the widespread adoption of smartphones by citizens represents ...