Now showing items 262-281 of 292

    • 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; 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 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; 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 ...
    • 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 ...
    • Transmission spectra changes produced by decreasing compactness of opal-like structures 

      Andueza Unanua, Ángel María; 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 ...
    • Ultra-compact planoconcave zoned metallic lens based on the fishnet metamaterial 

      Pacheco Peña, Víctor Upna; Orazbayev, Bakhtiyar Upna; Torres Landívar, Víctor Upna; Beruete Díaz, Miguel Upna; Navarro Cía, Miguel Upna (AIP Publishing, 2013)   Artículo / Artikulua  OpenAccess
      A 1.5λ0 -thick planoconcave zoned lens based on the fishnet metamaterial is demonstrated experimentally at millimeter wavelengths. The zoning technique applied allows a volume reduction of 60% compared to a full fishnet ...
    • Ultra-long (290 km) remote interrogation sensor network based on a random distributed feedback fiber laser 

      Miguel Soto, Verónica de; Leandro González, Daniel Upna; López-Amo Sáinz, Manuel Upna (Optical Society of America, 2018)   Artículo / Artikulua  OpenAccess
      In this work, an interferometric sensor has been interrogated 290 km away from the monitoring station, reaching the longest distance in fiber optic sensing up to date. This has been attained by employing a double-pumped ...
    • Ultra-wide band corrugated profiled horn antenna design 

      Teniente Vallinas, Jorge Upna; Gonzalo García, Ramón Upna; Río Bocio, Carlos del Upna (IEEE, 2002)   Artículo / Artikulua  OpenAccess
      Nowadays, an increasing number of applications need stable radiation patterns with low sidelobes and low crosspolar levels in a very wide bandwidth. Gaussian Profiled Horn Antennas (GPHA’s) have demonstrated its feasibility ...
    • Ultra-wideband metamaterial filter based on electroinductive-wave coupling between microstrips 

      Navarro Cía, Miguel Upna; Carrasco, J.M.; Beruete Díaz, Miguel Upna; Falcone Lanas, Francisco Javier Upna (EMW Publishing, 2009)   Artículo / Artikulua  OpenAccess
      In this work, we analyse the frequency response of microstrip lines coupled by complementary split ring resonators (CSRRs) etched on the ground plane supporting electroinductive waves (EIWs). The single-particle ...
    • Ultrahigh-sensitivity sensors based on thin-film coated long period gratings with reduced diameter, in transition mode and near the dispersion turning point 

      Del Villar, Ignacio Upna (Optical Society of America, 2015)   Artículo / Artikulua  OpenAccess
      The mode transition and the dispersion turning point have been explored for optimization of thin-film coated long period fiber gratings during the last years. In this work and additional parameter, the cladding diameter, ...
    • Upper bounds on scattering processes and metamaterial-inspired structures that reach them 

      Ederra Urzainqui, Íñigo Upna; Liberal Olleta, Íñigo Upna; Gonzalo García, Ramón Upna; Ziolkowski, Richard W. (IEEE, 2014)   Artículo / Artikulua  OpenAccess
      The physical limitations on time-harmonic scattering processes are investigated on the basis of the optical theorem. Previously derived least upper bounds on the total scattering and absorption cross-sections are obtained ...
    • Vertically coupled microring resonators using one epitaxial growth step and single-side lithography 

      García López, Óscar; Thourhout, Dries Van; Lasaosa Medarde, Daniel; López-Amo Sáinz, Manuel Upna; Baets, Roel; Galarza Galarza, Marko (Optical Society of America, 2015)   Artículo / Artikulua  OpenAccess
      A new concept for the fabrication of integrated microring resonators, requiring only one single epitaxial growth and two single-side lithographic steps, is proposed in what is the simplest fabrication scheme for vertical ...
    • Vibration detection using optical fiber sensors 

      Rodríguez García, Yoany; Corres Sanz, Jesús María Upna; Goicoechea Fernández, Javier Upna (Hindawi, 2010)   Artículo / Artikulua  OpenAccess
      Condition monitoring of heavy electromechanical equipment is commonly accomplished in the industry using vibration analysis. Several techniques, mainly based on capacitive and piezoelectric accelerometers, have been applied ...
    • Vibrato in singing voice: the link between source-filter and sinusoidal models 

      Carlosena García, Alfonso Upna; Arroabarren Alemán, Ixone Upna (Springer Open, 2004)   Artículo / Artikulua  OpenAccess
      The application of inverse filtering techniques for high-quality singing voice analysis/synthesis is discussed. In the context of source-filter models, inverse filtering provides a noninvasive method to extract the voice ...
    • Volatile organic compound optical fiber sensors: a review 

      Elosúa Aguado, César Upna; Matías Maestro, Ignacio Upna; Bariáin Aisa, Cándido Upna; Arregui San Martín, Francisco Javier Upna (MDPI, 2006)   Artículo / Artikulua  OpenAccess
      Volatile organic compound (VOC) detection is a topic of growing interest with applications in diverse fields, ranging from environmental uses to the food or chemical industries. Optical fiber VOC sensors offering new and ...